This market will resolve based on the data for the Global Land-Ocean Temperature Index for December 2025 versus the data points available for all other Decembers on record.

Note: If December 2025 is tied for first, second, or third hottest with another year, it will qualify for the bracket it ties with.

The primary resolution source for this market will be the figures found in the table titled "GLOBAL Land-Ocean Temperature Index in 0.01 degrees Celsius" under the column "Dec" (https://data.giss.nasa.gov/gistemp/tabledata_v4/GLB.Ts+dSST.txt). If NASA's "Global Temperature Index" is rendered permanently unavailable, other information from NASA may be used.
If no information for December 2025 is provided by NASA by January 31, 2026, 11:59 PM ET, a consensus of credible sources will be used to resolve this market.