The Hottest Year 2026 market asks one question: will the global average temperature in 2026 finish above every prior year on record. It is a binary Yes/No contract that resolves against NASA's GISS Land-Ocean Temperature Index, and it trades across roughly $645K in cumulative volume on two platforms. Resolution lands in January 2027, once GISS reports the full-year figure. The live board above ranks the current Kalshi and Polymarket prices on both sides.
The Hottest Year 2026 market is a single binary on the planet's annual temperature ranking. It resolves Yes only if 2026 ends warmer than 2025 and clears a fixed threshold on the NASA GISS index, and No otherwise. There is no middle outcome and no partial credit. With roughly $645K in cumulative volume across Kalshi and Polymarket, it is one of the more liquid climate contracts on the board, and the two platforms track each other closely. Current prices on both sides are on the live board above.
The contract hangs on one number reported by one source. NASA's Goddard Institute for Space Studies (GISS) publishes the unsmoothed Land-Ocean Temperature Index, a global anomaly measured against a 20th-century baseline. The market resolves Yes if the 2026 value comes in both above the 2025 value and above 1.28 degrees Celsius. That dual condition matters: a year can be extremely warm in absolute terms and still resolve No if it falls short of the immediately prior year. The question is not just "was 2026 hot" but "was 2026 the hottest reading GISS has ever recorded."
The backdrop is a string of record and near-record years. The global temperature trend has pushed the annual index steadily upward, and several recent years have set or matched all-time highs in the GISS series. That trend is what keeps the Yes side from being a throwaway. At the same time, year-to-year variation is real. The El Nino and La Nina cycle in the Pacific can swing a single year's global average by a meaningful fraction of a degree, which is exactly the margin this market turns on. A La Nina-leaning year tends to run cooler than its neighbors, and a single tenth of a degree is the difference between a new record and a near-miss.
That is why the price is not pinned near a certainty in either direction. The structural warming trend argues for Yes over a long horizon, but the specific bar here is beating the prior year and clearing a hard threshold in a single 12-month window. Cross-referencing other agencies sharpens the read: NOAA and the Copernicus Climate Change Service publish their own global temperature series, and while they differ slightly in method and baseline, a record year in one usually shows up as a record or near-record in the others. The GISS reading is the only one that settles this contract, but the broader consensus across datasets is the context traders weigh against the live price.
The Hottest Year 2026 market resolves in January 2027, after NASA GISS publishes the full-year unsmoothed Land-Ocean Temperature Index for 2026. It resolves Yes if that value is both above the 2025 figure and above 1.28 degrees Celsius, and No otherwise. The GISS report is the single source of truth, and revisions to the index after publication follow each platform's settlement rules.
For more weather and climate contracts, see the Category 4 hurricane landfall odds and the broader natural disaster 2026 market. Browse the full weather prediction markets hub for temperature, storm, and extreme-event contracts across both platforms, and see Genius Staff's analysis for ongoing coverage of how these markets price climate risk.
Resolves in January 2027, after NASA's Goddard Institute for Space Studies (GISS) publishes the full-year unsmoothed Land-Ocean Temperature Index for 2026. The market resolves Yes if the 2026 value is both above the 2025 value and above 1.28 degrees Celsius; otherwise it resolves No. The GISS report is the source of truth. Yes shares pay $1 each if the condition is met and No shares pay $1 each if it is not. Post-publication revisions to the GISS index, reporting delays, or a discontinuation of the dataset are handled under each platform's specific settlement rules.
The contract trades on both Kalshi and Polymarket, with the two platforms tracking each other closely on the Yes and No sides. The live board above shows the current cross-platform prices for whether 2026 finishes as the hottest year on record.
It resolves in January 2027, once NASA GISS publishes the full-year 2026 Land-Ocean Temperature Index. It resolves Yes only if the 2026 value is above 2025 and above 1.28 degrees Celsius.
NASA's Goddard Institute for Space Studies (GISS) unsmoothed Land-Ocean Temperature Index is the single source of truth. NOAA and Copernicus publish their own series, but only the GISS figure settles this contract.
The market is available on Kalshi and Polymarket, giving it two-platform coverage and roughly $645K in cumulative volume. Comparing the two sides on the live board above shows any cross-platform spread.
Watch the Pacific ENSO state and the mid-year GISS monthly anomaly reports through the summer of 2026. A swing toward El Nino or La Nina, and how each month's reading stacks against 2025, will move the price most before the January 2027 settlement.