Sep 11, 2026
Probability rose from 71.0% to 87.1% — a 16.1-point move over the past day.
Minimum Arctic sea ice extent this summer: Odds & Probability
Markets price the chance of this summer’s minimum Arctic sea ice extent slipping below 4m square kilometres at 95.3%. Resolution will use the lowest daily value recorded by NSIDC between 1 August and 1 October 2026.
95.3%+1.2 pts 24h
Will the minimum Arctic sea ice extent this summer be between 4.4m & 4.6m square kilometers?
Updated · Volume $85.2K
| Outcome | Probability | 24h |
|---|---|---|
| Will the minimum Arctic sea ice extent this summer be between 4.4m & 4.6m square kilometers? | 95.3% | +1.2 |
| Will the minimum Arctic sea ice extent this summer be between 4.2m & 4.4m square kilometers? | 2.3% | -1.2 |
| Will the minimum Arctic sea ice extent this summer be between 4.0m & 4.2m square kilometers? | 1.5% | -0.6 |
| Will the minimum Arctic sea ice extent this summer be less than 4m square kilometers? | 1.4% | -0.2 |
| Will the minimum Arctic sea ice extent this summer be between 4.6m & 4.8m square kilometers? | 0.3% | -0.4 |
| Will the minimum Arctic sea ice extent this summer be between 4.8m & 5m square kilometers? | 0.3% | -0.2 |
| Will the minimum Arctic sea ice extent this summer be at least 5m square kilometers? | 0.1% | -0.2 |
Beyond the headline sub-4m question, the market offers bets on specific extent ranges. A minimum between 4.4m and 4.6m sq km carries a probability of 2.3%, seen as a long shot. The 4.2–4.4m range stands at 1.5% (effectively ruled out), while 4.0–4.2m is priced at 1.4% (effectively ruled out). The 4.6–4.8m interval sits at 0.3% and is considered effectively ruled out. The remaining scenarios are all long shots.
Context
Sep 10, 2026
Probability rose from 73.3% to 82.8% — a 9.5-point move over the past day.
Sep 9, 2026
Probability rose from 56.4% to 67.0% — a 10.7-point move over the past day.
Sep 8, 2026
Probability rose from 31.4% to 58.0% — a 26.6-point move over the past day.
Sep 7, 2026
Probability rose from 44.5% to 61.9% — a 17.4-point move over the past day.
Show earlier updates
Sep 7, 2026
Probability rose from 39.4% to 54.6% — a 15.2-point move over the past day.
Sep 6, 2026
Probability rose from 39.8% to 46.7% — a 6.9-point move over the past day.
Sep 6, 2026
Probability rose from 30.5% to 40.6% — a 10.1-point move over the past day.
Sep 5, 2026
Probability fell from 60.4% to 57.1% — a 3.2-point move over the past day.
Sep 4, 2026
Probability rose from 48.9% to 60.4% — a 11.5-point move over the past day.
Arctic sea ice extent is a closely watched indicator of the planet's changing climate. This market asks whether the minimum daily extent—the low point of the summer melt—will drop below 4 million square kilometres. The monitoring window runs from 1 August to 1 October 2026, capturing the period when the ice typically reaches its smallest area. The National Snow and Ice Data Center provides the official numbers, updating its daily extent dataset throughout the season. The final resolution value will be the single lowest reading in that window, taken from the ‘NH-Daily-Extent’ tab of the Sea Ice Index. Currently, the market assigns a probability of 95.3% to the event, a view characterized as near-certain. This implies that most participants expect the minimum to stay at or above 4m sq km. The price has swung between 31.4% and 95.4% over the life of the contract, with total volume reaching $85.2K. The resolution process is straightforward. Once NSIDC publishes data for 1 October 2026, the market closes immediately. Only the officially reported minimum counts, to the nearest thousand square kilometres, and any later data revisions are disregarded. This mechanical clarity helps the market focus purely on the physical measurement.
FAQ
How does this market resolve?
It resolves based on the lowest daily Arctic sea ice extent recorded between 1 August and 1 October 2026, as published by the National Snow and Ice Data Center (NSIDC) in its ‘Sea Ice Index Daily Extent’ dataset. The minimum is taken from the ‘NH-Daily-Extent’ tab, and if that figure falls below 4 million square kilometres, the main outcome resolves positively.
What is the measurement precision?
The NSIDC reports extent values to the nearest thousand square kilometres. The market uses that same level of precision, so any difference within one thousand sq km would not change the resolution.
When will the outcome be known?
Once NSIDC releases data for 1 October 2026, the market will resolve. Any subsequent revisions to the data after that point are ignored.
What is the current probability of the minimum falling below 4m sq km?
As of 16 min ago, traders place the probability at 95.3%.
What if the NSIDC data is no longer available?
If the primary resolution source becomes unavailable, the market will select an alternative source to determine the minimum extent.
Data: Polymarket · Methodology · Not financial advice