Anchor on the climatological/trend-adjusted base rate for an August maximum ≥125°F at Furnace Creek (~30-40%), then adjust modestly up or down based on the August 2026 seasonal outlook, current summer heat regime (June–July 2026 peaks), and station data reliability, combining via weighted average since all factors reflect the same underlying summer heat regime.
## Cross-Market Signals ### Polymarket - "Will Elon Musk post 90-114 tweets from July 30 to August 1, 2026?" → Yes: 0.20, Volume: $117.7K - "Will Elon Musk post 115-139 tweets from July 30 to August 1, 2026?" → Yes: 0.01, Volume: $116.0K - "NATO x Russia military clash by August 31, 2026?" → Yes: 0.04, Volume: $170.3K - "Will Elon Musk post 65-89 tweets from July 30 to August 1, 2026?" → Yes: 0.79, Volume: $85.4K - "US-Iran Final Nuclear Deal by August 18, 2026?" → Yes: 0.02, Volume: $1.9M - "US announces end of Iranian blockade by August 7, 2026?" → Yes: 0.05, Volume: $161.3K
1. [sq1 | code_execution | STRONG cred 90 | DOWN | DATED] In the last 10 Augusts (2016-2025), Furnace Creek's monthly max reached ≥125°F in 3 of 10 years (2017, 2020, 2021), a 30% base rate. 2. [sq1 | code_execution | MODERATE cred 80 | UP | DATED] August maxima average 124.0°F with SD 2.94°F; a normal fit implies ~43% chance of ≥125°F assuming no trend. 3. [sq1 | code_execution | WEAK cred 65 | NEUTRAL | DATED] Fitted linear trend over the 10-year sample is slightly negative (-0.085°F/yr, p=0.81, not significant), giving a 2026 predicted max of 123.5°F and ~37% probability. 4. [sq1 | code_execution | MODERATE cred 75 | NEUTRAL | DATED] Bootstrap of the 10-year record gives mean probability 0.30 with a wide 95% CI of [0.10, 0.50]. 5. [sq2 | web_search | MODERATE cred 70 | NEUTRAL | RECENT] NOAA CPC's August 2026 outlook favors above-normal temperatures broadly across the U.S., with the strongest signal in the Southeast rather than the Southwest. 6. [sq2 | web_search | WEAK cred 60 | DOWN | RECENT] For the West, CPC kept above-normal probabilities conservative because cooler ocean water off the California coast works against warming. 7. [sq2 | web_search | MODERATE cred 75 | UP | RECENT] NWS noted a Southwest heat wave was set to intensify in late July 2026, with extreme heat warnings in effect for Death Valley July 23-27. 8. [sq3 | web_search | MODERATE cred 70 | DOWN | VERY_RECENT] Furnace Creek zone forecasts issued July 31, 2026 projected highs of only 120-123°F, and observed July 23 high was 120°F. 9. [sq3 | web_search | MODERATE cred 65 | DOWN | VERY_RECENT] A Newsweek report (~July 28, 2026) cited NWS forecasts of 123°F Saturday and 124°F Sunday for Death Valley, with possible daily records. 10. [sq3 | web_search | WEAK cred 30 | UP | VERY_RECENT] A social-media meteorologist post suggested Death Valley could approach 130°F with NWS forecasting 129°F in the hottest part of the valley on a late-July Sunday. 11. [sq3 | web_search | WEAK cred 45 | NEUTRAL | VERY_RECENT] No source found confirming Furnace Creek reached ≥125°F during June or July 2026; a climate tracker cited a 120.9°F figure for the month. 12. [sq4 | web_search | MODERATE cred 65 | UP | VERY_RECENT] Furnace Creek observations and NWS point forecasts were being published normally through late July 2026, with no reported station outage or relocation. ## Cross-Market Signals ### Polymarket - "Will Elon Musk post 90-114 tweets from July 30 to August 1, 2026?" → Yes: 0.20, Volume: $117.7K - "Will Elon Musk post 115-139 tweets from July 30 to August 1, 2026?" → Yes: 0.01, Volume: $116.0K - "NATO x Russia military clash by August 31, 2026?" → Yes: 0.04, Volume: $170.3K - "Will Elon Musk post 65-89 tweets from July 30 to August 1, 2026?" → Yes: 0.79, Volume: $85.4K - "US-Iran Final Nuclear Deal by August 18, 2026?" → Yes: 0.02, Volume: $1.9M - "US announces end of Iranian blockade by August 7, 2026?" → Yes: 0.05, Volume: $161.3K Information gaps: - Actual verified DEVC1 daily maxima for June-July 2026 (no IEM data pulled) - Longer base rate (30-50 years of August maxima), not just 2016-2025 - CPC August 2026 map probabilities specifically for Inyo County/Death Valley - ENSO state (La Niña/El Niño) for summer 2026 and its historical link to Death Valley August heat Key uncertainties: - Whether late-July 2026 heat wave peaked above or below 125°F at Furnace Creek - Whether the July regime persists into August (weak month-to-month persistence) - Monsoon moisture/cloud cover, which can cap Death Valley maxima in August - Wide bootstrap uncertainty (10-50%) on the base rate itself
You are an elite superforecaster using Tetlock-style Fermi decomposition. Estimate each sub-question INDEPENDENTLY, then provide a holistic estimate. The pipeline will mathematically recombine the sub-question estimates — your job is to give the most accurate per-component probabilities.
## Question
Will Death Valley hit 125 degrees in August 2026?
## Description / Resolution Criteria
## Description
Death Valley, California holds the [Guinness World Record](https://www.guinnessworldrecords.com/world-records/highest-recorded-temperature) for the hottest air temperature ever recorded, (134°F (56.7°C) in July 1913, though that observation has recently come under serious [dispute](https://journals.ametsoc.org/view/journals/bams/107/1/BAMS-D-24-0313.1.xml). In recent years, 129.9°F (54.4°C) was recorded in [August 2020](https://mesonet.agron.iastate.edu/sites/hist.phtml?station=DEVC1\&network=CA_DCP\&year=2020\&month=8), and 129°F was recorded as recently as [July 2024](https://mesonet.agron.iastate.edu/sites/hist.phtml?station=DEVC1\&network=CA_DCP\&year=2024\&month=7). 
Recent Augusts have reached the following highs:
| Year | August maximum |
| ---: | -------------: |
| 2016 | 122°F |
| 2017 | 127°F |
| 2018 | 122°F |
| 2019 | 122°F |
| 2020 | 130°F |
| 2021 | 126°F |
| 2022 | 123°F |
| 2023 | 120°F |
| 2024 | 124°F |
| 2025 | 124°F |
`{"format": "metac_reveal_and_close_in_period", "info": {"post_id": 44798, "question_id": 44945}}`
## Resolution Criteria
This question resolves as **Yes** if Death Valley, CA, records a maximum temperature on any day in August 2026 of greater than or equal to 125 °F, according to the observations at the [Furnace Creek Visitors Center](https://mesonet.agron.iastate.edu/sites/hist.phtml?station=DEVC1\&network=CA_DCP) weather station. 
## Fine Print
This question's information (resolution criteria, fine print, background info, etc) is synced with an [original identical question](https://www.metaculus.com/questions/44798) which opened on 2026-07-24 12:00:00. This question will resolve based on the resolution criteria and fine print of the linked original question. However, if this question would resolve differently than the original question, then this question will be annulled. Additionally, if the original question's resolution could have been known before this question opened, then this question will be annulled.
## Sub-question decomposition
- (w=0.45) Does the long-run historical base rate at Furnace Creek (DEVC1) imply that an August monthly maximum of ≥125°F occurs in a given year (i.e., is the unconditional climatological frequency above 40%)? — The dominant driver is climatology: in the last 10 Augusts only 2017 (127), 2020 (130), 2021 (126) reached ≥125°F, ~30%,
- (w=0.25) Do seasonal/monthly outlooks (CPC August 2026 temperature outlook, ENSO state, ridge pattern guidance) favor above-normal heat over the Desert Southwest in August 2026? — A strongly above-normal August outlook (heat dome persistence, weak/absent monsoon) meaningfully raises the odds of one
- (w=0.20) Did Death Valley (Furnace Creek) reach 125°F or higher at any point in June–July 2026, indicating an already hot summer regime? — Summer-to-summer persistence: years where early summer hits 125°F+ (e.g., 2020, 2021, 2024) tend to reflect a hot, ridge
- (w=0.10) Is the Furnace Creek Visitors Center (DEVC1) station reporting data reliably and consistently through late July 2026 (no outage/relocation that would suppress or bias reported maxima)? — Resolution depends on this specific station's observations; data gaps or sensor issues during peak heat days could preve
Combination rule: **weighted_average**
## Synthesized evidence
1. [sq1 | code_execution | STRONG cred 90 | DOWN | DATED] In the last 10 Augusts (2016-2025), Furnace Creek's monthly max reached ≥125°F in 3 of 10 years (2017, 2020, 2021), a 30% base rate.
2. [sq1 | code_execution | MODERATE cred 80 | UP | DATED] August maxima average 124.0°F with SD 2.94°F; a normal fit implies ~43% chance of ≥125°F assuming no trend.
3. [sq1 | code_execution | WEAK cred 65 | NEUTRAL | DATED] Fitted linear trend over the 10-year sample is slightly negative (-0.085°F/yr, p=0.81, not significant), giving a 2026 predicted max of 123.5°F and ~37% probability.
4. [sq1 | code_execution | MODERATE cred 75 | NEUTRAL | DATED] Bootstrap of the 10-year record gives mean probability 0.30 with a wide 95% CI of [0.10, 0.50].
5. [sq2 | web_search | MODERATE cred 70 | NEUTRAL | RECENT] NOAA CPC's August 2026 outlook favors above-normal temperatures broadly across the U.S., with the strongest signal in the Southeast rather than the Southwest.
6. [sq2 | web_search | WEAK cred 60 | DOWN | RECENT] For the West, CPC kept above-normal probabilities conservative because cooler ocean water off the California coast works against warming.
7. [sq2 | web_search | MODERATE cred 75 | UP | RECENT] NWS noted a Southwest heat wave was set to intensify in late July 2026, with extreme heat warnings in effect for Death Valley July 23-27.
8. [sq3 | web_search | MODERATE cred 70 | DOWN | VERY_RECENT] Furnace Creek zone forecasts issued July 31, 2026 projected highs of only 120-123°F, and observed July 23 high was 120°F.
9. [sq3 | web_search | MODERATE cred 65 | DOWN | VERY_RECENT] A Newsweek report (~July 28, 2026) cited NWS forecasts of 123°F Saturday and 124°F Sunday for Death Valley, with possible daily records.
10. [sq3 | web_search | WEAK cred 30 | UP | VERY_RECENT] A social-media meteorologist post suggested Death Valley could approach 130°F with NWS forecasting 129°F in the hottest part of the valley on a late-July Sunday.
11. [sq3 | web_search | WEAK cred 45 | NEUTRAL | VERY_RECENT] No source found confirming Furnace Creek reached ≥125°F during June or July 2026; a climate tracker cited a 120.9°F figure for the month.
12. [sq4 | web_search | MODERATE cred 65 | UP | VERY_RECENT] Furnace Creek observations and NWS point forecasts were being published normally through late July 2026, with no reported station outage or relocation.
## Cross-Market Signals
### Polymarket
- "Will Elon Musk post 90-114 tweets from July 30 to August 1, 2026?" → Yes: 0.20, Volume: $117.7K
- "Will Elon Musk post 115-139 tweets from July 30 to August 1, 2026?" → Yes: 0.01, Volume: $116.0K
- "NATO x Russia military clash by August 31, 2026?" → Yes: 0.04, Volume: $170.3K
- "Will Elon Musk post 65-89 tweets from July 30 to August 1, 2026?" → Yes: 0.79, Volume: $85.4K
- "US-Iran Final Nuclear Deal by August 18, 2026?" → Yes: 0.02, Volume: $1.9M
- "US announces end of Iranian blockade by August 7, 2026?" → Yes: 0.05, Volume: $161.3K
Information gaps:
- Actual verified DEVC1 daily maxima for June-July 2026 (no IEM data pulled)
- Longer base rate (30-50 years of August maxima), not just 2016-2025
- CPC August 2026 map probabilities specifically for Inyo County/Death Valley
- ENSO state (La Niña/El Niño) for summer 2026 and its historical link to Death Valley August heat
Key uncertainties:
- Whether late-July 2026 heat wave peaked above or below 125°F at Furnace Creek
- Whether the July regime persists into August (weak month-to-month persistence)
- Monsoon moisture/cloud cover, which can cap Death Valley maxima in August
- Wide bootstrap uncertainty (10-50%) on the base rate itself
## Required pre-forecast walkthrough
Before giving probabilities, walk through these explicitly:
(a) The time left until the question resolves.
(b) The status quo outcome — what happens if nothing changes from today.
(c) A brief scenario that results in NO.
(d) A brief scenario that results in YES.
## Calibration guidance
- **Estimate each sub-question in isolation.** Do not let your answer to one sub-question anchor your answer to another. This is the core of Fermi decomposition — independence forces more careful reasoning per factor.
- **Anchor on the status quo.** Require strong specific evidence to move far from it.
- 0.05 / 0.95 require strong, multi-source evidence. Avoid >0.97 or <0.03 unless the outcome is already settled or near-tautological — overconfident misses are punished heavily by the log score.
- **Anchor on prediction markets.** If liquid market prices (Polymarket / Kalshi) or a community forecast appear in the evidence, treat them as a strong, well-calibrated prior. Your final estimate should rarely sit more than ~15 percentage points from a liquid market on the SAME question — move further only with specific evidence the market lacks.
- **Treat research as fallible, not ground truth.** A single-source or "very recent" claim — especially one the evidence flags as unverified, possibly AI-generated, or low-credibility — must not drive you to near-certainty. When a load-bearing fact is unverified, keep at least 10-15% on the chance it is wrong.
- **Also provide a holistic estimate** — your overall gut feeling about the main question, BEFORE you see the mathematical combination. This serves as a sanity check: if the Fermi result and holistic estimate diverge wildly, something is wrong.
## Output
Return ONLY valid JSON, no markdown fences:
{
"rationale": "<address (a) (b) (c) (d) above — 5-8 sentences total>",
"sub_question_estimates": {
"sq1": <float in [0.01, 0.99]>,
"sq2": <float in [0.01, 0.99]>,
"sq3": <float in [0.01, 0.99]>,
"sq4": <float in [0.01, 0.99]>
},
"holistic_p_yes": <float in [0.01, 0.99] — your overall estimate ignoring the decomposition>,
"what_would_change_my_mind": "<1-2 sentences: what new info would push you above 70% or below 30%>"
}
{
"forecast": {
"combination_logic": "weighted_average",
"evidence_brief": "1. [sq1 | code_execution | STRONG cred 90 | DOWN | DATED] In the last 10 Augusts (2016-2025), Furnace Creek\u0027s monthly max reached \u2265125\u00b0F in 3 of 10 years (2017, 2020, 2021), a 30% base rate.\n2. [sq1 | code_execution | MODERATE cred 80 | UP | DATED] August maxima average 124.0\u00b0F with SD 2.94\u00b0F; a normal fit implies ~43% chance of \u2265125\u00b0F assuming no trend.\n3. [sq1 | code_execution | WEAK cred 65 | NEUTRAL | DATED] Fitted linear trend over the 10-year sample is slightly negative (-0.085\u00b0F/yr, p=0.81, not significant), giving a 2026 predicted max of 123.5\u00b0F and ~37% probability.\n4. [sq1 | code_execution | MODERATE cred 75 | NEUTRAL | DATED] Bootstrap of the 10-year record gives mean probability 0.30 with a wide 95% CI of [0.10, 0.50].\n5. [sq2 | web_search | MODERATE cred 70 | NEUTRAL | RECENT] NOAA CPC\u0027s August 2026 outlook favors above-normal temperatures broadly across the U.S., with the strongest signal in the Southeast rather than the Southwest.\n6. [sq2 | web_search | WEAK cred 60 | DOWN | RECENT] For the West, CPC kept above-normal probabilities conservative because cooler ocean water off the California coast works against warming.\n7. [sq2 | web_search | MODERATE cred 75 | UP | RECENT] NWS noted a Southwest heat wave was set to intensify in late July 2026, with extreme heat warnings in effect for Death Valley July 23-27.\n8. [sq3 | web_search | MODERATE cred 70 | DOWN | VERY_RECENT] Furnace Creek zone forecasts issued July 31, 2026 projected highs of only 120-123\u00b0F, and observed July 23 high was 120\u00b0F.\n9. [sq3 | web_search | MODERATE cred 65 | DOWN | VERY_RECENT] A Newsweek report (~July 28, 2026) cited NWS forecasts of 123\u00b0F Saturday and 124\u00b0F Sunday for Death Valley, with possible daily records.\n10. [sq3 | web_search | WEAK cred 30 | UP | VERY_RECENT] A social-media meteorologist post suggested Death Valley could approach 130\u00b0F with NWS forecasting 129\u00b0F in the hottest part of the valley on a late-July Sunday.\n11. [sq3 | web_search | WEAK cred 45 | NEUTRAL | VERY_RECENT] No source found confirming Furnace Creek reached \u2265125\u00b0F during June or July 2026; a climate tracker cited a 120.9\u00b0F figure for the month.\n12. [sq4 | web_search | MODERATE cred 65 | UP | VERY_RECENT] Furnace Creek observations and NWS point forecasts were being published normally through late July 2026, with no reported station outage or relocation.\n\n## Cross-Market Signals\n\n### Polymarket\n- \"Will Elon Musk post 90-114 tweets from July 30 to August 1, 2026?\" \u2192 Yes: 0.20, Volume: $117.7K\n- \"Will Elon Musk post 115-139 tweets from July 30 to August 1, 2026?\" \u2192 Yes: 0.01, Volume: $116.0K\n- \"NATO x Russia military clash by August 31, 2026?\" \u2192 Yes: 0.04, Volume: $170.3K\n- \"Will Elon Musk post 65-89 tweets from July 30 to August 1, 2026?\" \u2192 Yes: 0.79, Volume: $85.4K\n- \"US-Iran Final Nuclear Deal by August 18, 2026?\" \u2192 Yes: 0.02, Volume: $1.9M\n- \"US announces end of Iranian blockade by August 7, 2026?\" \u2192 Yes: 0.05, Volume: $161.3K\n\nInformation gaps:\n - Actual verified DEVC1 daily maxima for June-July 2026 (no IEM data pulled)\n - Longer base rate (30-50 years of August maxima), not just 2016-2025\n - CPC August 2026 map probabilities specifically for Inyo County/Death Valley\n - ENSO state (La Ni\u00f1a/El Ni\u00f1o) for summer 2026 and its historical link to Death Valley August heat\n\nKey uncertainties:\n - Whether late-July 2026 heat wave peaked above or below 125\u00b0F at Furnace Creek\n - Whether the July regime persists into August (weak month-to-month persistence)\n - Monsoon moisture/cloud cover, which can cap Death Valley maxima in August\n - Wide bootstrap uncertainty (10-50%) on the base rate itself",
"forecast_prompt": "You are an elite superforecaster using Tetlock-style Fermi decomposition. Estimate each sub-question INDEPENDENTLY, then provide a holistic estimate. The pipeline will mathematically recombine the sub-question estimates \u2014 your job is to give the most accurate per-component probabilities.\n\n## Question\nWill Death Valley hit 125 degrees in August 2026?\n\n## Description / Resolution Criteria\n## Description\nDeath Valley, California holds the [Guinness World Record](https://www.guinnessworldrecords.com/world-records/highest-recorded-temperature) for the hottest air temperature ever recorded, (134\u00b0F (56.7\u00b0C) in July 1913, though that observation has recently come under serious [dispute](https://journals.ametsoc.org/view/journals/bams/107/1/BAMS-D-24-0313.1.xml). In recent years, 129.9\u00b0F (54.4\u00b0C) was recorded in [August 2020](https://mesonet.agron.iastate.edu/sites/hist.phtml?station=DEVC1\\\u0026network=CA_DCP\\\u0026year=2020\\\u0026month=8), and 129\u00b0F was recorded as recently as [July 2024](https://mesonet.agron.iastate.edu/sites/hist.phtml?station=DEVC1\\\u0026network=CA_DCP\\\u0026year=2024\\\u0026month=7).\u0026#x20;\n\nRecent Augusts have reached the following highs:\n\n| Year | August maximum |\n| ---: | -------------: |\n| 2016 | 122\u00b0F |\n| 2017 | 127\u00b0F |\n| 2018 | 122\u00b0F |\n| 2019 | 122\u00b0F |\n| 2020 | 130\u00b0F |\n| 2021 | 126\u00b0F |\n| 2022 | 123\u00b0F |\n| 2023 | 120\u00b0F |\n| 2024 | 124\u00b0F |\n| 2025 | 124\u00b0F |\n\n`{\"format\": \"metac_reveal_and_close_in_period\", \"info\": {\"post_id\": 44798, \"question_id\": 44945}}`\n\n## Resolution Criteria\nThis question resolves as **Yes** if Death Valley, CA, records a maximum temperature on any day in August 2026 of greater than or equal to 125 \u00b0F, according to the observations at the [Furnace Creek Visitors Center](https://mesonet.agron.iastate.edu/sites/hist.phtml?station=DEVC1\\\u0026network=CA_DCP) weather station.\u0026#x20;\n\n## Fine Print\nThis question\u0027s information (resolution criteria, fine print, background info, etc) is synced with an [original identical question](https://www.metaculus.com/questions/44798) which opened on 2026-07-24 12:00:00. This question will resolve based on the resolution criteria and fine print of the linked original question. However, if this question would resolve differently than the original question, then this question will be annulled. Additionally, if the original question\u0027s resolution could have been known before this question opened, then this question will be annulled.\n\n## Sub-question decomposition\n- (w=0.45) Does the long-run historical base rate at Furnace Creek (DEVC1) imply that an August monthly maximum of \u2265125\u00b0F occurs in a given year (i.e., is the unconditional climatological frequency above 40%)? \u2014 The dominant driver is climatology: in the last 10 Augusts only 2017 (127), 2020 (130), 2021 (126) reached \u2265125\u00b0F, ~30%,\n- (w=0.25) Do seasonal/monthly outlooks (CPC August 2026 temperature outlook, ENSO state, ridge pattern guidance) favor above-normal heat over the Desert Southwest in August 2026? \u2014 A strongly above-normal August outlook (heat dome persistence, weak/absent monsoon) meaningfully raises the odds of one \n- (w=0.20) Did Death Valley (Furnace Creek) reach 125\u00b0F or higher at any point in June\u2013July 2026, indicating an already hot summer regime? \u2014 Summer-to-summer persistence: years where early summer hits 125\u00b0F+ (e.g., 2020, 2021, 2024) tend to reflect a hot, ridge\n- (w=0.10) Is the Furnace Creek Visitors Center (DEVC1) station reporting data reliably and consistently through late July 2026 (no outage/relocation that would suppress or bias reported maxima)? \u2014 Resolution depends on this specific station\u0027s observations; data gaps or sensor issues during peak heat days could preve\n\nCombination rule: **weighted_average**\n\n## Synthesized evidence\n1. [sq1 | code_execution | STRONG cred 90 | DOWN | DATED] In the last 10 Augusts (2016-2025), Furnace Creek\u0027s monthly max reached \u2265125\u00b0F in 3 of 10 years (2017, 2020, 2021), a 30% base rate.\n2. [sq1 | code_execution | MODERATE cred 80 | UP | DATED] August maxima average 124.0\u00b0F with SD 2.94\u00b0F; a normal fit implies ~43% chance of \u2265125\u00b0F assuming no trend.\n3. [sq1 | code_execution | WEAK cred 65 | NEUTRAL | DATED] Fitted linear trend over the 10-year sample is slightly negative (-0.085\u00b0F/yr, p=0.81, not significant), giving a 2026 predicted max of 123.5\u00b0F and ~37% probability.\n4. [sq1 | code_execution | MODERATE cred 75 | NEUTRAL | DATED] Bootstrap of the 10-year record gives mean probability 0.30 with a wide 95% CI of [0.10, 0.50].\n5. [sq2 | web_search | MODERATE cred 70 | NEUTRAL | RECENT] NOAA CPC\u0027s August 2026 outlook favors above-normal temperatures broadly across the U.S., with the strongest signal in the Southeast rather than the Southwest.\n6. [sq2 | web_search | WEAK cred 60 | DOWN | RECENT] For the West, CPC kept above-normal probabilities conservative because cooler ocean water off the California coast works against warming.\n7. [sq2 | web_search | MODERATE cred 75 | UP | RECENT] NWS noted a Southwest heat wave was set to intensify in late July 2026, with extreme heat warnings in effect for Death Valley July 23-27.\n8. [sq3 | web_search | MODERATE cred 70 | DOWN | VERY_RECENT] Furnace Creek zone forecasts issued July 31, 2026 projected highs of only 120-123\u00b0F, and observed July 23 high was 120\u00b0F.\n9. [sq3 | web_search | MODERATE cred 65 | DOWN | VERY_RECENT] A Newsweek report (~July 28, 2026) cited NWS forecasts of 123\u00b0F Saturday and 124\u00b0F Sunday for Death Valley, with possible daily records.\n10. [sq3 | web_search | WEAK cred 30 | UP | VERY_RECENT] A social-media meteorologist post suggested Death Valley could approach 130\u00b0F with NWS forecasting 129\u00b0F in the hottest part of the valley on a late-July Sunday.\n11. [sq3 | web_search | WEAK cred 45 | NEUTRAL | VERY_RECENT] No source found confirming Furnace Creek reached \u2265125\u00b0F during June or July 2026; a climate tracker cited a 120.9\u00b0F figure for the month.\n12. [sq4 | web_search | MODERATE cred 65 | UP | VERY_RECENT] Furnace Creek observations and NWS point forecasts were being published normally through late July 2026, with no reported station outage or relocation.\n\n## Cross-Market Signals\n\n### Polymarket\n- \"Will Elon Musk post 90-114 tweets from July 30 to August 1, 2026?\" \u2192 Yes: 0.20, Volume: $117.7K\n- \"Will Elon Musk post 115-139 tweets from July 30 to August 1, 2026?\" \u2192 Yes: 0.01, Volume: $116.0K\n- \"NATO x Russia military clash by August 31, 2026?\" \u2192 Yes: 0.04, Volume: $170.3K\n- \"Will Elon Musk post 65-89 tweets from July 30 to August 1, 2026?\" \u2192 Yes: 0.79, Volume: $85.4K\n- \"US-Iran Final Nuclear Deal by August 18, 2026?\" \u2192 Yes: 0.02, Volume: $1.9M\n- \"US announces end of Iranian blockade by August 7, 2026?\" \u2192 Yes: 0.05, Volume: $161.3K\n\nInformation gaps:\n - Actual verified DEVC1 daily maxima for June-July 2026 (no IEM data pulled)\n - Longer base rate (30-50 years of August maxima), not just 2016-2025\n - CPC August 2026 map probabilities specifically for Inyo County/Death Valley\n - ENSO state (La Ni\u00f1a/El Ni\u00f1o) for summer 2026 and its historical link to Death Valley August heat\n\nKey uncertainties:\n - Whether late-July 2026 heat wave peaked above or below 125\u00b0F at Furnace Creek\n - Whether the July regime persists into August (weak month-to-month persistence)\n - Monsoon moisture/cloud cover, which can cap Death Valley maxima in August\n - Wide bootstrap uncertainty (10-50%) on the base rate itself\n\n## Required pre-forecast walkthrough\n\nBefore giving probabilities, walk through these explicitly:\n (a) The time left until the question resolves.\n (b) The status quo outcome \u2014 what happens if nothing changes from today.\n (c) A brief scenario that results in NO.\n (d) A brief scenario that results in YES.\n\n## Calibration guidance\n\n- **Estimate each sub-question in isolation.** Do not let your answer to one sub-question anchor your answer to another. This is the core of Fermi decomposition \u2014 independence forces more careful reasoning per factor.\n- **Anchor on the status quo.** Require strong specific evidence to move far from it.\n- 0.05 / 0.95 require strong, multi-source evidence. Avoid \u003e0.97 or \u003c0.03 unless the outcome is already settled or near-tautological \u2014 overconfident misses are punished heavily by the log score.\n- **Anchor on prediction markets.** If liquid market prices (Polymarket / Kalshi) or a community forecast appear in the evidence, treat them as a strong, well-calibrated prior. Your final estimate should rarely sit more than ~15 percentage points from a liquid market on the SAME question \u2014 move further only with specific evidence the market lacks.\n- **Treat research as fallible, not ground truth.** A single-source or \"very recent\" claim \u2014 especially one the evidence flags as unverified, possibly AI-generated, or low-credibility \u2014 must not drive you to near-certainty. When a load-bearing fact is unverified, keep at least 10-15% on the chance it is wrong.\n- **Also provide a holistic estimate** \u2014 your overall gut feeling about the main question, BEFORE you see the mathematical combination. This serves as a sanity check: if the Fermi result and holistic estimate diverge wildly, something is wrong.\n\n## Output\n\nReturn ONLY valid JSON, no markdown fences:\n\n{\n \"rationale\": \"\u003caddress (a) (b) (c) (d) above \u2014 5-8 sentences total\u003e\",\n \"sub_question_estimates\": {\n \"sq1\": \u003cfloat in [0.01, 0.99]\u003e,\n \"sq2\": \u003cfloat in [0.01, 0.99]\u003e,\n \"sq3\": \u003cfloat in [0.01, 0.99]\u003e,\n \"sq4\": \u003cfloat in [0.01, 0.99]\u003e\n },\n \"holistic_p_yes\": \u003cfloat in [0.01, 0.99] \u2014 your overall estimate ignoring the decomposition\u003e,\n \"what_would_change_my_mind\": \"\u003c1-2 sentences: what new info would push you above 70% or below 30%\u003e\"\n}\n",
"holistic_p_yes": 0.3,
"models": [
"opus",
"secondary"
],
"p_yes": 0.41105,
"rationale": "(a) The question opened July 24, 2026 and resolves at the end of August 2026, so roughly a full month of Death Valley\u0027s peak heat season remains \u2014 plenty of time for a single 125\u00b0F day, which is the only requirement. (b) Status quo: climatology dominates. Furnace Creek\u0027s August monthly max averaged 124.0\u00b0F over 2016-2025 with only 3 of 10 years reaching \u2265125\u00b0F (2017, 2020, 2021), so the default is a narrow miss (~30-40%). (c) NO scenario: the pattern seen in late July 2026 continues \u2014 a Pacific with cool coastal SSTs, CPC\u0027s conservative above-normal signal for the West, and NWS Furnace Creek forecasts topping out at 120-124\u00b0F \u2014 plus any monsoon moisture/cloud cover, which regularly caps Death Valley August maxima in the low 120s. (d) YES scenario: a strong, dry subtropical ridge parks over the Great Basin for several days in mid-August with no monsoon interference; Furnace Creek then easily spikes to 125-128\u00b0F, as it did in 2017, 2020, and 2021 \u2014 this requires only one day. Notably, evidence suggests June-July 2026 did not clearly reach 125\u00b0F at this station, which is unusual (July normally peaks 126-129\u00b0F) and hints at a genuinely less extreme summer regime, arguing for a probability at or slightly below base rate. The station appears to be reporting normally, so data availability is unlikely to be the binding constraint. Overall I land near the low-30s, modestly below the naive normal-distribution fit of 43% because the observed frequency is 30% and current-season signals lean cool for the Southwest.",
"sub_question_estimates": {
"sq1": 0.34,
"sq2": 0.5,
"sq3": 0.42,
"sq4": 0.93
},
"what_would_change_my_mind": "Verified DEVC1 data showing June-July 2026 already hit 127\u00b0F+ plus model guidance for a strong mid-August Great Basin ridge would push me above 70%; confirmation that July 2026 peaked at only ~121-123\u00b0F alongside an active monsoon/cool-Pacific August outlook would push me below 25%."
},
"plan": {
"combination_logic": "weighted_average",
"domain": "climate",
"n_sub_qs": 4,
"n_tools": 4,
"reasoning_approach": "Anchor on the climatological/trend-adjusted base rate for an August maximum \u2265125\u00b0F at Furnace Creek (~30-40%), then adjust modestly up or down based on the August 2026 seasonal outlook, current summer heat regime (June\u2013July 2026 peaks), and station data reliability, combining via weighted average since all factors reflect the same underlying summer heat regime.",
"sub_questions": [
{
"id": "sq1",
"question": "Does the long-run historical base rate at Furnace Creek (DEVC1) imply that an August monthly maximum of \u2265125\u00b0F occurs in a given year (i.e., is the unconditional climatological frequency above 40%)?",
"rationale": "The dominant driver is climatology: in the last 10 Augusts only 2017 (127), 2020 (130), 2021 (126) reached \u2265125\u00b0F, ~30%, but a longer record plus warming trend may shift this. This anchors the forecast.",
"weight": 0.45
},
{
"id": "sq2",
"question": "Do seasonal/monthly outlooks (CPC August 2026 temperature outlook, ENSO state, ridge pattern guidance) favor above-normal heat over the Desert Southwest in August 2026?",
"rationale": "A strongly above-normal August outlook (heat dome persistence, weak/absent monsoon) meaningfully raises the odds of one extreme day; an active monsoon suppresses peak highs.",
"weight": 0.25
},
{
"id": "sq3",
"question": "Did Death Valley (Furnace Creek) reach 125\u00b0F or higher at any point in June\u2013July 2026, indicating an already hot summer regime?",
"rationale": "Summer-to-summer persistence: years where early summer hits 125\u00b0F+ (e.g., 2020, 2021, 2024) tend to reflect a hot, ridge-dominated regime that can extend into August.",
"weight": 0.2
},
{
"id": "sq4",
"question": "Is the Furnace Creek Visitors Center (DEVC1) station reporting data reliably and consistently through late July 2026 (no outage/relocation that would suppress or bias reported maxima)?",
"rationale": "Resolution depends on this specific station\u0027s observations; data gaps or sensor issues during peak heat days could prevent a qualifying reading.",
"weight": 0.1
}
],
"tool_requests": [
{
"parameters": {
"code": "import numpy as np\nfrom scipy import stats\n\n# August maximum temperatures at Furnace Creek / Death Valley (F), recent record\naug = {2016:122,2017:127,2018:122,2019:122,2020:130,2021:126,2022:123,2023:120,2024:124,2025:124}\nvals = np.array(list(aug.values()), float)\nyears = np.array(list(aug.keys()), float)\nprint(\u0027mean\u0027, vals.mean(), \u0027sd\u0027, vals.std(ddof=1))\nprint(\u0027base rate \u003e=125 last10:\u0027, (vals\u003e=125).mean())\n\n# linear trend\nsl, ic, r, p, se = stats.linregress(years, vals)\nprint(\u0027trend F/yr\u0027, round(sl,3), \u0027p\u0027, round(p,3), \u0027pred2026\u0027, round(ic+sl*2026,2))\n\n# Normal approx probability \u003e=125 using detrended residual sd and 2026 trend prediction\nresid = vals - (ic+sl*years)\nsd = resid.std(ddof=1)\nmu_trend = ic+sl*2026\nprint(\u0027P(\u003e=125) trend-normal\u0027, round(1-stats.norm.cdf(124.5, mu_trend, sd),3))\nprint(\u0027P(\u003e=125) flat-normal\u0027, round(1-stats.norm.cdf(124.5, vals.mean(), vals.std(ddof=1)),3))\n\n# Longer-context sensitivity: assume slightly hotter distribution (warming) mu+0.5,+1.0\nfor bump in [0,0.5,1.0,1.5]:\n print(\u0027bump\u0027,bump, round(1-stats.norm.cdf(124.5, vals.mean()+bump, vals.std(ddof=1)),3))\n\n# Bootstrap of last-10 exceedance rate\nrng=np.random.default_rng(0)\nbs=[ (rng.choice(vals,10,replace=True)\u003e=125).mean() for _ in range(20000)]\nprint(\u0027bootstrap mean\u0027, np.mean(bs), \u0027CI\u0027, np.percentile(bs,[5,95]))\n",
"description": "Estimate base rate and trend-adjusted probability that August max at Death Valley \u003e=125F"
},
"target_sub_questions": [
"sq1"
],
"tool_name": "code_execution"
},
{
"parameters": {
"brief": "Find (1) NOAA CPC\u0027s monthly/seasonal temperature outlook for August 2026 for California/Desert Southwest, (2) current ENSO status and Southwest monsoon outlook for August 2026, and (3) the highest temperatures recorded at Death Valley / Furnace Creek in June and July 2026, including any excessive heat warnings or records. Report specific numbers and dates.",
"max_searches": 4,
"question_title": "Will Death Valley hit 125 degrees in August 2026?"
},
"target_sub_questions": [
"sq2",
"sq3"
],
"tool_name": "claude_news"
},
{
"parameters": {
"queries": [
"Death Valley Furnace Creek highest temperature July 2026",
"CPC August 2026 temperature outlook Southwest above normal",
"Death Valley heat record 2026 excessive heat warning"
]
},
"target_sub_questions": [
"sq2",
"sq3",
"sq4"
],
"tool_name": "web_search"
},
{
"parameters": {
"lookback_days": 60,
"queries": [
"Death Valley record heat 2026",
"Southwest heat dome July 2026 forecast",
"Death Valley 130 degrees 2026 national park heat"
]
},
"target_sub_questions": [
"sq3",
"sq4"
],
"tool_name": "article_search"
}
]
},
"question": {
"close_time": "2026-08-01T12:00:00Z",
"description": "## Description\nDeath Valley, California holds the [Guinness World Record](https://www.guinnessworldrecords.com/world-records/highest-recorded-temperature) for the hottest air temperature ever recorded, (134\u00b0F (56.7\u00b0C) in July 1913, though that observation has recently come under serious [dispute](https://journals.ametsoc.org/view/journals/bams/107/1/BAMS-D-24-0313.1.xml). In recent years, 129.9\u00b0F (54.4\u00b0C) was recorded in [August 2020](https://mesonet.agron.iastate.edu/sites/hist.phtml?station=DEVC1\\\u0026network=CA_DCP\\\u0026year=2020\\\u0026month=8), and 129\u00b0F was recorded as recently as [July 2024](https://mesonet.agron.iastate.edu/sites/hist.phtml?station=DEVC1\\\u0026network=CA_DCP\\\u0026year=2024\\\u0026month=7).\u0026#x20;\n\nRecent Augusts have reached the following highs:\n\n| Year | August maximum |\n| ---: | -------------: |\n| 2016 | 122\u00b0F |\n| 2017 | 127\u00b0F |\n| 2018 | 122\u00b0F |\n| 2019 | 122\u00b0F |\n| 2020 | 130\u00b0F |\n| 2021 | 126\u00b0F |\n| 2022 | 123\u00b0F |\n| 2023 | 120\u00b0F |\n| 2024 | 124\u00b0F |\n| 2025 | 124\u00b0F |\n\n`{\"format\": \"metac_reveal_and_close_in_period\", \"info\": {\"post_id\": 44798, \"question_id\": 44945}}`\n\n## Resolution Criteria\nThis question resolves as **Yes** if Death Valley, CA, records a maximum temperature on any day in August 2026 of greater than or equal to 125 \u00b0F, according to the observations at the [Furnace Creek Visitors Center](https://mesonet.agron.iastate.edu/sites/hist.phtml?station=DEVC1\\\u0026network=CA_DCP) weather station.\u0026#x20;\n\n## Fine Print\nThis question\u0027s information (resolution criteria, fine print, background info, etc) is synced with an [original identical question](https://www.metaculus.com/questions/44798) which opened on 2026-07-24 12:00:00. This question will resolve based on the resolution criteria and fine print of the linked original question. However, if this question would resolve differently than the original question, then this question will be annulled. Additionally, if the original question\u0027s resolution could have been known before this question opened, then this question will be annulled.",
"question_type": "binary",
"title": "Will Death Valley hit 125 degrees in August 2026?"
},
"research": {
"cross_market_brief": "## Cross-Market Signals\n\n### Polymarket\n- \"Will Elon Musk post 90-114 tweets from July 30 to August 1, 2026?\" \u2192 Yes: 0.20, Volume: $117.7K\n- \"Will Elon Musk post 115-139 tweets from July 30 to August 1, 2026?\" \u2192 Yes: 0.01, Volume: $116.0K\n- \"NATO x Russia military clash by August 31, 2026?\" \u2192 Yes: 0.04, Volume: $170.3K\n- \"Will Elon Musk post 65-89 tweets from July 30 to August 1, 2026?\" \u2192 Yes: 0.79, Volume: $85.4K\n- \"US-Iran Final Nuclear Deal by August 18, 2026?\" \u2192 Yes: 0.02, Volume: $1.9M\n- \"US announces end of Iranian blockade by August 7, 2026?\" \u2192 Yes: 0.05, Volume: $161.3K",
"errors": [],
"has_cross_market": true,
"n_errors": 0,
"n_tools": 4,
"tools": [
{
"elapsed_s": 1.48,
"error": null,
"success": true,
"summary": "Estimate base rate and trend-adjusted probability that Augus",
"tool_name": "code_execution"
},
{
"elapsed_s": 22.98,
"error": null,
"success": true,
"summary": "13 citations",
"tool_name": "claude_news"
},
{
"elapsed_s": 36.64,
"error": null,
"success": true,
"summary": "0 results",
"tool_name": "web_search"
},
{
"elapsed_s": 0.94,
"error": null,
"success": true,
"summary": "20 articles",
"tool_name": "article_search"
}
]
},
"synthesis": {
"evidence": [
{
"claim": "In the last 10 Augusts (2016-2025), Furnace Creek\u0027s monthly max reached \u2265125\u00b0F in 3 of 10 years (2017, 2020, 2021), a 30% base rate.",
"credibility": 90,
"direction": "DOWN",
"priced_in": true,
"recency": "DATED",
"source": "code_execution",
"strength": "STRONG",
"sub_question_id": "sq1"
},
{
"claim": "August maxima average 124.0\u00b0F with SD 2.94\u00b0F; a normal fit implies ~43% chance of \u2265125\u00b0F assuming no trend.",
"credibility": 80,
"direction": "UP",
"priced_in": true,
"recency": "DATED",
"source": "code_execution",
"strength": "MODERATE",
"sub_question_id": "sq1"
},
{
"claim": "Fitted linear trend over the 10-year sample is slightly negative (-0.085\u00b0F/yr, p=0.81, not significant), giving a 2026 predicted max of 123.5\u00b0F and ~37% probability.",
"credibility": 65,
"direction": "NEUTRAL",
"priced_in": true,
"recency": "DATED",
"source": "code_execution",
"strength": "WEAK",
"sub_question_id": "sq1"
},
{
"claim": "Bootstrap of the 10-year record gives mean probability 0.30 with a wide 95% CI of [0.10, 0.50].",
"credibility": 75,
"direction": "NEUTRAL",
"priced_in": true,
"recency": "DATED",
"source": "code_execution",
"strength": "MODERATE",
"sub_question_id": "sq1"
},
{
"claim": "NOAA CPC\u0027s August 2026 outlook favors above-normal temperatures broadly across the U.S., with the strongest signal in the Southeast rather than the Southwest.",
"credibility": 70,
"direction": "NEUTRAL",
"priced_in": true,
"recency": "RECENT",
"source": "web_search",
"strength": "MODERATE",
"sub_question_id": "sq2"
},
{
"claim": "For the West, CPC kept above-normal probabilities conservative because cooler ocean water off the California coast works against warming.",
"credibility": 60,
"direction": "DOWN",
"priced_in": false,
"recency": "RECENT",
"source": "web_search",
"strength": "WEAK",
"sub_question_id": "sq2"
},
{
"claim": "NWS noted a Southwest heat wave was set to intensify in late July 2026, with extreme heat warnings in effect for Death Valley July 23-27.",
"credibility": 75,
"direction": "UP",
"priced_in": true,
"recency": "RECENT",
"source": "web_search",
"strength": "MODERATE",
"sub_question_id": "sq2"
},
{
"claim": "Furnace Creek zone forecasts issued July 31, 2026 projected highs of only 120-123\u00b0F, and observed July 23 high was 120\u00b0F.",
"credibility": 70,
"direction": "DOWN",
"priced_in": false,
"recency": "VERY_RECENT",
"source": "web_search",
"strength": "MODERATE",
"sub_question_id": "sq3"
},
{
"claim": "A Newsweek report (~July 28, 2026) cited NWS forecasts of 123\u00b0F Saturday and 124\u00b0F Sunday for Death Valley, with possible daily records.",
"credibility": 65,
"direction": "DOWN",
"priced_in": false,
"recency": "VERY_RECENT",
"source": "web_search",
"strength": "MODERATE",
"sub_question_id": "sq3"
},
{
"claim": "A social-media meteorologist post suggested Death Valley could approach 130\u00b0F with NWS forecasting 129\u00b0F in the hottest part of the valley on a late-July Sunday.",
"credibility": 30,
"direction": "UP",
"priced_in": false,
"recency": "VERY_RECENT",
"source": "web_search",
"strength": "WEAK",
"sub_question_id": "sq3"
},
{
"claim": "No source found confirming Furnace Creek reached \u2265125\u00b0F during June or July 2026; a climate tracker cited a 120.9\u00b0F figure for the month.",
"credibility": 45,
"direction": "NEUTRAL",
"priced_in": false,
"recency": "VERY_RECENT",
"source": "web_search",
"strength": "WEAK",
"sub_question_id": "sq3"
},
{
"claim": "Furnace Creek observations and NWS point forecasts were being published normally through late July 2026, with no reported station outage or relocation.",
"credibility": 65,
"direction": "UP",
"priced_in": true,
"recency": "VERY_RECENT",
"source": "web_search",
"strength": "MODERATE",
"sub_question_id": "sq4"
}
],
"information_gaps": [
"Actual verified DEVC1 daily maxima for June-July 2026 (no IEM data pulled)",
"Longer base rate (30-50 years of August maxima), not just 2016-2025",
"CPC August 2026 map probabilities specifically for Inyo County/Death Valley",
"ENSO state (La Ni\u00f1a/El Ni\u00f1o) for summer 2026 and its historical link to Death Valley August heat"
],
"key_uncertainties": [
"Whether late-July 2026 heat wave peaked above or below 125\u00b0F at Furnace Creek",
"Whether the July regime persists into August (weak month-to-month persistence)",
"Monsoon moisture/cloud cover, which can cap Death Valley maxima in August",
"Wide bootstrap uncertainty (10-50%) on the base rate itself"
],
"n_evidence": 12
},
"timings": {
"forecast": 68.67,
"plan": 29.42,
"research": 36.64,
"synthesis": 31.24
}
}