This market has settled: RESOLVED
Settled on May 20, 2026
Will global temperature increase by between 1.25ºC and 1.29ºC in May 2026?
Will global temperature increase by between 1.25ºC and 1.29ºC in May 2026? Odds: 0.9% YES on Polymarket. See live prices and trade this market.
This extremely narrow temperature band has drawn minimal trader interest, reflected in basement-level odds that suggest market participants view such precise warming as unlikely within a specific month. The specificity matters because global temperature anomalies typically fluctuate by 0.1-0.2°C month-to-month, making a single narrow band prediction a difficult target even if overall warming trends upward.
Current Odds
| Platform | Yes | No | Volume | Trade |
|---|---|---|---|---|
| Polymarket | 0.9% | 99.1% | $10K | Trade on Polymarket |
Market Analysis
The bull case rests on continued acceleration of anthropogenic warming combined with a potential El Niño event persisting into mid-2026, which historically amplifies global temperatures by 0.1-0.3°C above baseline. May 2026 falls in Northern Hemisphere spring when land masses warm rapidly, potentially pushing anomalies higher. If current warming rates of roughly 0.25°C per decade hold and a moderate El Niño develops by late 2025, the market band becomes plausible. Temperature data providers like NOAA, UAH, and Berkeley Earth will report April 2026 anomalies around May 15th, providing crucial directional signals two weeks before market expiry.
The bear case dominates because this band represents less than 5% of the likely distribution around expected 2026 warming. May typically shows lower anomalies than June or July in seasonal patterns, and the precise 1.25-1.29°C range requires alignment of multiple variables. A La Niña or neutral ENSO state developing by early 2026 would suppress odds materially. Measurement methodology differences between agencies (satellite vs. surface records) mean even “same month” data can vary by 0.1-0.15°C, creating execution risk.
Traders should monitor ENSO forecasts through December 2025 and January 2026 closely—these determine roughly 30-40% of month-to-month variation. Watch preliminary April 2026 anomalies around May 15 for the clearest signal. The El Niño Southern Oscillation prediction released monthly by NOAA’s Climate Prediction Center becomes critical; any forecast shift toward neutral or La Niña conditions before Q1 2026 should compress these already-thin odds further.
Frequently Asked Questions
Why is a single-month temperature band so unlikely to hit when warming is accelerating?
Month-to-month noise from weather patterns and ENSO cycles typically creates ±0.15°C swings around any trend, making a 0.04°C-wide band a statistical long shot even if the directional forecast is correct.
How much does seasonal variation affect May specifically versus other months?
May typically runs 0.05-0.1°C cooler than June and July due to oceanic heat lag, meaning if trend warming would push June into this band, May likely falls short.
Will different temperature measurement agencies (NOAA, UAH, Berkeley Earth) agree on whether this band was hit?
Historical divergences between surface and satellite records can reach 0.1-0.15°C, so one agency could report YES while another reports NO, creating dispute risk depending on market resolution criteria.