Min Arctic sea ice extent this summer?

This market will resolve according to the minimum Arctic sea ice extent for all days between August 1, 2026 and October 1, 2026, as published by the National Snow and Ice Data Center. This market will remain open until data has been published for October 1, 2026, at which point it will resolve immediately. Any revisions to sea ice extent recorded after data is published for October 1, 2026 will not be considered. The resolution source for this market measures temperatures to thousands of square kilometers (e.g. 4.255 million sq km). Thus, this is the level of precision that will be used when resolving the market. The resolution source for this market will be information from the National Snow and Ice Data Center, specifically the minimum value recorded for any day between August 1, 2026 and October 1, 2026 in the “NH-Daily-Extent” tab of the “Sea Ice Index Daily Extent” data set, available at https://nsidc.org/sea-ice-today/sea-ice-tools. If this resolution source becomes unavailable, another resolution source will be chosen.

How trading works

Polymarket uses a central limit order book (CLOB) model — you can buy or sell shares of any outcome at the current market price, or place limit orders. Prices represent implied probability: a $0.65 contract means the market prices a 65% chance of that outcome.