Global temperature by month: 2026 vs 2024 and 2025

Will 2026 Be the Hottest Year on Record? Prediction Markets vs. NASA’s Data

Kalshi gives 66% that 2026 will be the hottest year on record. NASA’s data so far puts it just behind.

NASA’s global temperature index averages 1.23°C above the 1951–1980 baseline for January–September 2026, against the record 1.28°C for 2024. To pass 2024, the remaining 3 months would need to average about 1.42°C, a level only 3 single months have reached in NASA’s record.

Kalshi market data and official statistics, pulled Oct 15, 2026, 7:54 AM ET. Updated daily (NASA updates monthly).

By Arthur Angelo, PredictionScout Research · Updated Oct 15, 2026, 7:54 AM ET

66%chance 2026 is hottest (Kalshi)
1.23°C2026 so far (NASA)
1.28°Crecord (2024)
1.42°Cneeded per month for the rest of the year

Key findings

  • 2026 so far: 1.23°C. Record year: 2024 at 1.28°C. Kalshi’s market resolves on NASA’s annual figure, which must top both 1.28°C and 2025.
  • Needed for a record: about 1.42°C a month from October to December. September 2026 came in at 1.38°C. NASA’s annual figure is computed from its monthly values and rounded, so the exact threshold can shift by about 0.01°C.
  • Monthly “hottest ever” markets: 30 of 32 called right. Priced 24 hours before each market closed. Brier score 0.035.
  • NASA check: 31 of 32 agree. We checked each monthly settlement against whether NASA’s value topped every earlier year for that month. Kalshi’s short monthly rule does not name a data source, so differences are listed below.
  • Next: Will Oct 2026 be the hottest Oct ever? Market: 78%. NASA’s record for that month: 1.34°C.
Global temperature by month: 2026 vs 2024 and 2025Global temperature by month: 2026 vs 2024 and 20250.80.91.11.21.41.5JanFebMarAprMayJunJulAugSepOctNovDec202620242025°C vs 1951–1980NASA GISS GISTEMP v4; PredictionScout
NASA GISTEMP v4 monthly global land-ocean temperature anomalies.

Past “hottest year” markets

YearKalshi resultNASA annual anomaly (°C)
2022Not a record0.89
2023Hottest on record1.17
2024Hottest on record1.28
2025Not a record1.18

Monthly “hottest ever” markets

MonthChance 24h beforeKalshi resultNASA anomaly (°C)Prior NASA record for the monthNASA agrees
Sep 20262%NO1.381.48✓
Aug 2026100%YES1.421.30✓
Jul 202621%NO1.241.20differs
Jun 20260%NO1.171.23✓
May 20261%NO1.131.16✓
Apr 20260%NO1.161.32✓
Mar 20264%NO1.301.39✓
Feb 20261%NO1.231.43✓
Jan 20260%NO1.081.37✓
Nov 20251%NO1.211.40✓
Oct 20251%NO1.181.34✓
Sep 20251%NO1.241.48✓
Aug 20250%NO1.171.30✓
Jul 20250%NO1.021.20✓
Jun 20251%NO1.061.23✓
May 20250%NO1.071.16✓
Apr 20251%NO1.241.32✓
Mar 20258%NO1.361.39✓
Feb 20250%NO1.251.43✓
Jan 2025100%YES1.371.25✓
Dec 20240%NO1.261.35✓
Nov 20246%NO1.291.40✓
Oct 20241%NO1.341.34✓
Sep 20246%NO1.211.48✓
Aug 202448%YES1.301.19✓
Jul 202430%YES1.201.19✓
Jun 202498%YES1.231.08✓
May 202498%YES1.160.99✓
Apr 202494%YES1.321.11✓
Mar 202450%YES1.391.35✓
Feb 202478%YES1.431.36✓
Jan 202490%YES1.251.18✓

Download the data

Monthly markets vs NASA (CSV)NASA monthly anomalies (2015 on) (CSV)

One row per settled market period. Per-contract price histories are not included. Free to reuse under CC BY 4.0 with a link back to this page.

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Methodology

  • Official data. NASA GISS Surface Temperature Analysis v4, global land-ocean index (GLB.Ts+dSST.csv), anomalies vs 1951–1980. NASA revises past values slightly each month; we use the current file.
  • Markets. Kalshi’s KXGTEMP (hottest year; resolves on NASA’s unsmoothed annual value) and KXHMONTH/HMONTH (hottest month ever), from Kalshi’s public API. Monthly prices are taken 24 hours before close (bid/ask midpoint when the spread is 10¢ or less, otherwise last trade).
  • Needed value. (record × 12 − sum of months so far) ÷ months remaining.
  • Limits. Few annual markets; monthly settlement may rely on a source other than NASA; NASA revisions can change past months by a few hundredths of a degree. Nothing here is investment advice. Last run: Oct 15, 2026, 7:54 AM ET.

Cite this research

Suggested citation: PredictionScout. (2026, October 15). Will 2026 Be the Hottest Year on Record? Prediction Markets vs. NASA's Data. https://predictionscout.com/research/hottest-year-prediction-markets-nasa/

For a chart or news story: “Source: PredictionScout analysis of public exchange data (https://predictionscout.com/research/hottest-year-prediction-markets-nasa/)”

The data and charts on this page are free to reuse under CC BY 4.0 with a link back to this page. Temperature data: NASA Goddard Institute for Space Studies (GISTEMP v4). Market data: Kalshi.

Data sources: prices and volumes come from the public APIs of Kalshi and Polymarket, with temperature data from NASA GISS. All trademarks belong to their owners. PredictionScout is independent and not affiliated with any exchange. Nothing here is investment, betting, or legal advice.

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