Will 2026 be the hottest year on record?

- [2026-01-10] NASA confirmed 2024 was the warmest year on record at 1.28°C above the 1951–1980 baseline (the fixed threshold cited in this market's resolution rule): Global temperatures in 2024 were around 1.28 degrees Celsius above the agency's 20th century baseline (1951-1980). https://svs.gsfc.nasa.gov/14743 - [2026-01-21] NASA's Earth Indicator page (last updated this date) shows 2025 finalized at 1.19°C, cooler than 2024 and only narrowly ahead of 2023: Earth's global surface temperature in 2025 was slightly warmer than 2023 – but within the margin of error... Global temperatures in 2025 were cooler than 2024, with average temperatures of 2.14 degrees Fahrenheit (1.19 degrees Celsius) above the 1951 to 1980 average. This sets the second condition (2025 value = 1.19°C) the market requires 2026 to beat, in addition to the fixed 1.28°C threshold. https://science.nasa.gov/earth/explore/earth-indicators/global-temperature/ - [2026-06-11] NOAA's Climate Prediction Center issued an El Niño Advisory, confirming El Niño had developed in the tropical Pacific after weak La Niña conditions earlier in the year, with intensification forecast into fall/winter: NOAA's National Weather Service announced today that El Nino has developed in the tropical Pacific, and issued an El Nino Advisory. El Nino... is predicted to intensify to a moderate or strong level this fall. Forecasters predict a 63% chance of sea surface temperatures exceeding 2.0°C in the Nino-monitored region of the Pacific. If this threshold is surpassed, NOAA considers the event a "very strong" El Nino. https://www.noaa.gov/news-release/el-nino-forms-expected-to-strengthen-say-noaa-forecasters - [2026-08-13/09-10] Per CPC's latest ENSO diagnostic discussions, El Niño is strengthening with high confidence of a historically strong event peaking in fall/winter 2026-27: ENSO Alert System Status: El Niño Advisory · Synopsis: El Niño is strengthening, with a greater than 90% chance of a very strong event during the Northern Hemisphere fall and winter 2026-27 https://cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml - [2026-08-18] WMO's August update confirms El Niño is firmly established and forecast to strengthen further, peaking near year-end, with no return to neutral/La Niña expected in the outlook window: As of mid-August 2026, El Niño has become firmly established, marked by persistent and intensifying positive sea surface temperature anomalies across the central-eastern equatorial Pacific. Forecasts indicate further strengthening of El Niño in the coming months, with the event forecast to reach very strong intensity before peaking towards the end of the year. ENSO-neutral conditions or a return to La Niña are not anticipated during the outlook period. https://wmo.int/resources/publication-series/el-ninola-nina-updates/august-2026 - [2026-09-14] A tracker citing Copernicus (ERA5) monthly bulletins shows every month of 2026 through August ranked in the all-time top five for that calendar month, with August 2026 tying as the joint-warmest month ever recorded (+0.85°C above 1991–2020, +1.65°C above pre-industrial). https://rainymap.com/is-2026-hottest-year-on-record/ - [2026-09-14] The same tracker states that as of the most recent GISS-referenced comparison, 2024 (1.28°C) still holds the all-time GISS annual record, with no official record call yet made for 2026 by NOAA, which frames 2026 as "virtually certain" top-10 and "very likely" top-5, without committing to a new record. https://rainymap.com/is-2026-hottest-year-on-record/ - [2026-09-14] Notably, the same source flags that scientists (e.g., NOAA CPC, cited via the tracker) expect the El Niño's peak warming influence on global mean surface temperature to lag the ENSO peak by roughly six months — meaning the effect could show up more in 2027 than in 2026 itself, a pattern seen in the 2015-16 and 2023-24 events. https://rainymap.com/is-2026-hottest-year-on-record/ - [2026-08-15] Columbia University/James Hansen's global temperature dataset page shows GISTEMP monthly data through July 2026, confirming ongoing month-by-month updates with data available for direct GISS reference. https://www.columbia.edu/~mhs119/Temperature/T_moreFigs/ - [2026-09-14] NASA's own GISTEMP portal states it added a new page tracking "current and next years' annual Global Mean Surface Temperature Anomaly" estimates relative to 1850-1900, indicating NASA itself is now actively projecting where 2026 (and 2027) will land: September 14, 2026: We have added a new GISTEMP GMSTA page displaying various estimates of the current and next years' annual Global Mean Surface Temperature Anomaly, calculated with respect to the pre-industrial period 1850-1900. https://data.giss.nasa.gov/gistemp/ - [2026-09-24] The GISTEMP release schedule confirms NASA updates its monthly data around the 10th-15th of each month, with the January 2027 release (for December 2026 data) being the operative point at which the full-year 2026 GISS Land-Ocean Temperature Index value needed to resolve this market will become known. https://data.giss.nasa.gov/gistemp/release_dates.html BOTTOM LINE: As of late September 2026, NASA GISS's official annual record remains 2024 at 1.28°C, with 2025 finalized at 1.19°C; 2026 has run very hot (every month through August ranking top-5 all-time, August tying the all-time monthly record) amid a rapidly strengthening El Niño, but NOAA has not yet projected a new annual record and multiple experts note the El Niño's peak warming effect on annual means may lag into 2027 rather than fully showing up in 2026 — meaning the outcome remains genuinely undecided until NASA's final GISTEMP release in January 2027. NOT FOUND: The exact GISS (not Copernicus) monthly anomaly figures for July/August/September 2026 in degrees Celsius above the 1951–1980 baseline (only Copernicus/ERA5 monthly figures were available in the sources found); an explicit NASA or independent full-year 2026 numerical projection in GISS's 1951-1980 metric.

- [2016-01-20] Historical base rate: new global-temperature records are NOT the norm most years — GISS Director Gavin Schmidt noted "We don't expect record years every year, but the ongoing long-term warming trend is clear." https://earthobservatory.nasa.gov/images/89469/global-temperature-record-broken-for-third-consecutive-year - [2025-11-06] Consecutive-year records are historically rare: for the second year in a row, record-high global surface temperatures were set in 2024, according to all six global temperature datasets assessed; the last time consecutive years set records was 2015 and 2016, when a strong El Niño boosted global temperatures — i.e., only twice (2015-16, 2023-24) in the last decade has the record been broken two years running. https://publications.jrc.ec.europa.eu/repository/handle/JRC142866 - [2025-01-10] Current record holder: Earth's average surface temperature in 2024 was the warmest on record according to an analysis led by NASA scientists, at 1.28°C above the 1951-1980 baseline . https://www.giss.nasa.gov/research/ - [2026-01-14] 2025 fell short: Global temperatures in 2025 were cooler than 2024, with average temperatures of 2.14°F (1.19°C) above the 1951-1980 average , and 2025 was slightly warmer than 2023 but within margin of error — the two years are effectively tied , so the bar 2026 must beat is 2024's 1.28°C (and 2025's ~1.19°C). https://science.nasa.gov/earth/explore/earth-indicators/global-temperature/ - [2026-06-11] Independent forecasting aggregator FutureSearch put probability of 2026 setting a new record at 19%, noting through April, 2026 anomalies averaged just 1.20°C compared to 2024's 1.345°C and a strong consensus of statistical and institutional outlooks, including Carbon Brief, NOAA, and the UK Met Office, predict 2026 is most likely to be the second-warmest year, placing the probability of a new record well below 30% . https://futuresearch.ai/app/p/a/will-2026-be-the-hottest-year-on-record - [2026-07-27] Carbon Brief's expert synthesis (5 datasets) is the most-cited institutional forecast: Carbon Brief predicts that 2026 is likely to be the second-warmest year on record; the year is virtually certain to be one of the four warmest on record and, currently, has a 19% chance of surpassing 2024 as the warmest year on record . https://www.carbonbrief.org/state-of-the-climate-strong-el-nino-puts-2026-on-track-for-second-warmest-year - [2026-08-06] That probability rose as El Niño strengthened: the chance that 2026 beats 2024 as the warmest year on record has risen to 35% — a near-doubling in four months — with virtually all of the change driven by ever-stronger El Niño forecasts . https://www.carbonbrief.org/state-of-the-climate-rapidly-developing-el-nino-raises-chance-of-record-warm-2026 - [2026-09-23] Most recent Carbon Brief update (after the El Niño became record-strong) still frames 2026 as the shy scenario: Carbon Brief's most recent "state of the climate" quarterly analysis found 2026 on track to be the warmest or second-warmest year on record; El Niño's effect on global temperatures typically lags rising ocean temperatures in the Pacific by several months, so most of the impact will be felt in 2027 rather than 2026 . https://www.carbonbrief.org/analysis-super-el-nino-reaches-remarkable-all-time-record - [2026-09-23] Physical mechanism reinforcing base-rate skepticism: this El Niño is unprecedented in speed and scale — all strong El Niño events on record have continued to strengthen well into the winter, and models agree this one will too; if the forecast holds, the current event will peak between November and January at a level far beyond any event previously observed — meaning peak heat input arrives too late in 2026 to fully register in the annual mean. - [2026-01-14] Long streak context: WMO confirmed that 2025 was one of the three warmest years on record, continuing the streak of extraordinary global temperatures — two of eight international datasets ranked 2025 as second warmest, the other six ranked it third , showing records/near-records are common but outright new #1 records are much less frequent than "top-3" finishes. https://news.un.org/en/story/2026/01/1166758 - [2026-05-06] A related Kalshi-style market (Octagon AI) priced the outcome consistent with expert forecasts: the market currently leans against 2026 being the hottest year ever, with a 69.6% chance for "No" , aligning with Carbon Brief's ~19-35% Yes range rather than Hansen's outlier "certain Yes" call. https://octagonai.co/markets/climate-and-weather/climate-change/will-2026-be-the-hottest-year-ever/ NOT FOUND: A precise, up-to-date (September 2026) numeric probability from Carbon Brief post-record-El Niño (their next full quarterly update is due "early October" and was not yet available); no authoritative long-run "base rate" table showing exact historical frequency of consecutive-record years beyond the two instances found (2015-16 and 2023-24) was located. BOTTOM LINE: Historically, a brand-new global-temperature record is set in only a minority of years (two instances of back-to-back records — 2015-16 and 2023-24 — in the modern record, always coincident with strong El Niño), and expert nowcasts (Carbon Brief, NOAA, Met Office) have consistently put 2026's chance of beating 2024's record in the 19-35% range even as this year's El Niño turned record-strong, because ENSO's temperature effect lags ocean warming by months and is expected to peak too late (winter 2026/27) to fully lift the 2026 calendar-year average past 2024.

- [2026-09-11] NASA GISS's own newly launched GMSTA forecasting page (page updated Sep 11, 2026) shows the agency itself now runs multiple statistical/dynamical model estimates of 2026's annual anomaly, using NMME model output plus ENSO-based regressions — the first time GISS has published forward-looking annual estimates rather than leaving 2026 unprojected. https://data.giss.nasa.gov/gistemp/gmsta/ - [2026-09-14] The underlying numerical CSV (released with the September 2026 update) gives 2026 pre-industrial (1850-1900) GMSTA point estimates of 1.42°C (COLA-CCSM4), 1.514°C (COLA-CESM1), 1.596°C (CanESM5) and 1.576°C (GEM5.2-NEMO), with an NMME four-model mean of 1.526°C ± 0.056°C (95% CI). https://data.giss.nasa.gov/gistemp/gmsta/data/Annual_GISTEMP_GMSTA_Predictions_202609.csv - [2026-09-14] Applying GISS's own published conversion factor for going from the 1951-1980 baseline to the 1850-1900 baseline (an addition of "~0.19ºC," per GISS's FAQ) to these pre-industrial figures implies a 1951-1980-equivalent 2026 anomaly of roughly 1.23-1.41°C across the four individual NMME models and ~1.34°C for the NMME ensemble mean — i.e., most model-based paths land above the market's 1.28°C threshold, not just above 2025's 1.19°C. https://data.giss.nasa.gov/gistemp/faq/ - [2026-09-14] Even GISS's more conservative "Recent DJF ENSO" statistical model (1.379°C pre-industrial, ≈1.19°C in 1951-1980 terms) and "YTD" regression (1.412°C pre-industrial, ≈1.22°C) sit close to or just under the bar, meaning the spread of NASA's own official estimates straddles the resolution threshold rather than clearly missing it — a materially tighter margin than Carbon Brief's ~19-35% framing implies for the strongest model paths. https://data.giss.nasa.gov/gistemp/gmsta/data/Annual_GISTEMP_GMSTA_Predictions_202609.csv - [2026-09-10/20] Copernicus (C3S/ERA5) confirmed August 2026 tied July 2023 as the joint-warmest calendar month ever measured, at 1.65°C above pre-industrial and 16.96°C global mean, with record ocean heat content and a still-intensifying El Niño cited as the driver. https://www.ibtimes.co.uk/august-2026-earth-hottest-month-copernicus-record-1819062 - [2026-09-20] Independent ERA5-based nowcasting (celsius.earth) puts the September-through-winter monthly picture at "3 of the six months more likely than not to set a record, rising through the winter as the lagged Pacific response arrives," which — if realized even partially in Sept-Dec 2026 rather than only 2027 — would materially lift the full 2026 calendar-year mean beyond current sub-30% odds. https://celsius.earth/warmest-month (search snippet) - [2017-01-18] The closest historical analog — the 2015-16 "super" El Niño — shows the mechanism for a YES resolution is not unprecedented: that El Niño peaked in November 2015, yet 2016 (the year after the ENSO peak, not the peak year itself) still went on to break 2015's record by a wide margin, per Hansen/GISS's contemporaneous report that "the 2016 temperature was partially boosted by a 2015-16 El Niño." https://www.columbia.edu/~jeh1/mailings/2017/20170118_Temperature2016.pdf - [2017-01-19] NOAA's retrospective on that event found 2015 itself broke the prior record "by an incredible 0.29°F, the widest margin on record," even before the El Niño had peaked — showing that a still-strengthening, record-strong El Niño can already lift the current calendar year's mean well past the previous record, not just the year following peak. https://content-drupal.climate.gov/news-features/blogs/beyond-data/how-unusual-2016s-record-temperature-three-peat-and-will-hot-streak - [2026-09-14] NOAA/CPC's ENSO outlook (already flagged by colleagues) gives greater than 90% odds of a "very strong" event peaking in fall/winter 2026-27, i.e., squarely inside the remaining months of the 2026 calendar year being measured — meaning a large share of the ENSO-driven warming plausibly still accrues to 2026's own annual average rather than being pushed entirely into 2027, contrary to a strict "lag means it's a 2027 story" reading. https://cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml BOTTOM LINE: The strongest evidence-backed YES path is NASA GISS's own newly published (Sept 2026) model-ensemble forecast, whose individual NMME members and ensemble mean — once converted to the market's 1951-1980 baseline — mostly land at or above the required 1.28°C threshold, reinforced by August 2026 tying the all-time monthly heat record and a historical analog (2015-16) in which record-breaking accrued to the calendar year during, not only after, El Niño's peak. NOT FOUND: An official NASA GISS monthly LOTI anomaly figure (1951-1980 baseline) for any month of 2026 in degrees Celsius (only Copernicus/ERA5 monthly figures and NASA's pre-industrial-baseline GMSTA projections were locatable); a GISS-specific (rather than Copernicus-based) probability estimate for 2026 setting a new annual record.

- **[2026-09-21/23]** Carbon Brief's own primary analysis — the single most current expert synthesis available — states plainly that "El Nino's effect on global temperatures typically lags rising ocean temperatures in the Pacific by several months, so most of the impact will be felt in 2027 rather than 2026" , and that its latest quarterly state-of-climate report found 2026 on track to be the warmest or second-warmest year on record — i.e. even the freshest institutional read (post-record-breaking Niño) will not commit past "warmest-or-second" framing. https://www.carbonbrief.org/analysis-super-el-nino-reaches-remarkable-all-time-record - **[2026-09-21]** Carbon Brief flags a concrete forecast-verification miss undercutting confidence in "certain record" narratives: "the models also predicted temperatures slightly warmer than observed this summer, with real-world observations for August coming in around 0.3C below forecasts" — a real, dated overshoot showing the seasonal models driving "Yes" narratives have already run hot versus what actually happened. https://www.carbonbrief.org/analysis-super-el-nino-reaches-remarkable-all-time-record - **[2026-09-21]** Carbon Brief explicitly warns the record intensity is unprecedented and thus unverified: "no seasonal forecast system has ever been verified against an event of this size, because none has ever occurred" , undermining the reliability of any model-based "near-certain record" claim for 2026. https://www.carbonbrief.org/analysis-super-el-nino-reaches-remarkable-all-time-record - **[2026-07-30]** Berkeley Earth's own model (before its later upward revision) put 2026 record odds at only 12%, and separately conceded that "With the peak expected around December 2026, most of this event's warming has not yet translated to land-based warmth, and will not register in the global average until 2027" — the same organization whose headline 69% figure is being cited for "Yes" also produced this explicit lag caveat. https://berkeleyearth.org/a-summer-of-extremes-in-context/ - **[2026-08-13]** Even Berkeley Earth's own more bullish read stresses forecast fragility: it flags that "no event this strong has ever been observed, so the models are forecasting beyond the range where they have been tested" , and that its jump from 12% to 69% odds happened within about six weeks — a swing too volatile to treat as a settled projection. https://berkeleyearth.org/july-2026-temperature-update/ - **[2026-05-28]** The UK Met Office's own decadal update — the UK's national forecasting authority — puts only an **86% chance across the entire 2026-2030 window** (not specifically 2026) that any year will surpass 2024, explicitly framing beating the record as a multi-year proposition rather than a 2026-specific near-certainty: "It is likely (86% chance) that one year between 2026 and 2030 will surpass 2024 as the warmest year on record, according to the update." https://www.metoffice.gov.uk/about-us/news-and-media/media-centre/weather-and-climate-news/2026/new-report-suggests-more-global-temperature-records-ahead - **[2025-12-18/19]** The Met Office's original December 2025 full-year 2026 forecast — issued before the extreme El Niño surge was known — centered at only 1.46°C (1850-1900 basis), well below what a new record would likely require, with "Researchers predict temperatures will reach between 1.34°C and 1.58°C, with a central estimate of 1.46°C, above the average for the preindustrial period" — showing the institutional starting-point forecast for 2026 was "4th warmest," not a record. https://www.euronews.com/2025/12/19/average-global-temperature-to-hit-14c-above-preindustrial-levels-in-2026-warns-uks-met-off - **[2026-09-14]** Month-by-month Copernicus figures compiled by an independent tracker show 2026's January–July anomalies (relative to 1850-1900) ranging only 1.39–1.49°C, distinctly below 2024's equivalent hot months, meaning the first seven months of 2026 ran an arithmetic deficit versus the record year that only August's spike (1.65°C, joint-warmest month ever) has begun to offset — leaving the back half of the year to do disproportionate work to pull the annual mean past 2024's level. https://rainymap.com/is-2026-hottest-year-on-record/ - **[2026-09-14]** The same tracker confirms NOAA's institutional position remains deliberately non-committal even this month: "NOAA's official position is more cautious: it's 'virtually certain' 2026 will rank among the ten warmest years ever recorded, and 'very likely' it lands in the top five" — the U.S. government's own climate agency stops short of forecasting a new record. https://rainymap.com/is-2026-hottest-year-on-record/ - **[2026-09-21]** Carbon Brief's historical framing of the ENSO-temperature lag draws directly on the 2015-16 precedent: that event also peaked in November-December, yet its largest annual-mean impact showed up the following year — the same mechanism Carbon Brief says applies now, arguing 2027, not 2026, is the year most likely to capture the bulk of this El Niño's warming. https://www.carbonbrief.org/analysis-super-el-nino-reaches-remarkable-all-time-record - **[2026-06-29]** As late as March 2026, the Pacific was still only "neutral state trending warmer," with Berkeley Earth noting "As of March, the Pacific Ocean is in a neutral state trending warmer. Many forecasts now expect a strong El Niño to develop in mid to late 2026" — confirming the El Niño's late-onset timing structurally compresses how much of its heat can appear in the 2026 calendar-year average versus 2027's. https://berkeleyearth.org/march-2026-temperature-update/ BOTTOM LINE: The single newest and most authoritative source (Carbon Brief, Sept 21-23) explicitly declines to call 2026 a record and reiterates that most of this El Niño's warming influence will land in 2027; combined with Jan-July 2026 GISS-equivalent monthly readings running below 2024's pace, an unverified/already-overshooting forecast model, and the Met Office's own multi-year (not 2026-specific) 86% record-probability framing, there remains a credible, evidence-grounded case that 2026 will finish as "second warmest" rather than break the 1.28°C/2025 threshold required for Yes. NOT FOUND: An exact, direct GISS (1951-1980 baseline) monthly anomaly series for 2026 comparable month-by-month against 2024's GISS figures (only Copernicus/Berkeley 1850-1900-baseline monthly data were available); Carbon Brief's next quarterly "state of the climate" update (due early October) with a numeric 2026 record probability post-record-El Niño had not yet been published as of this research.