Will global temperature increase by less than 1.10ºC in May 2026?

Prediction markets put the probability at 10%: Will global temperature increase by less than 1.10ºC in May 2026. Currently, markets see this as unlikely (10% YES). The projections by the U.N.

What’s Happening

The World Meteorological Organization and the UK Met Office released joint projections on May 28, 2026 indicating that average global temperatures over the next five years are forecast to reach near-record levels, with a 75% probability that the average global temperature between 2026 and 2030 will exceed the 1.5°C warming threshold agreed under the Paris Accord. The agencies also project Arctic warming of nearly 1.66°C by 2030, alongside elevated drought and wildfire risk for the Amazon basin. The question of whether the global temperature increase by less than 1.10ºC in May 2026 materialises sits well below the baseline trajectory now described by the agencies. [NBC News, May 28]

According to the WMO's annual decadal update, the Earth is "overwhelmingly likely" to repeatedly surpass the international climate threshold set as safe and break its hottest-year record within the five-year window. Research scientist Melissa Seabrook of the Met Office stated there is "very clear evidence that the climate is warming and that the global average temperature is continuing to rise." Recent monthly anomalies from Copernicus and NOAA have consistently registered above 1.30°C relative to the pre-industrial baseline since 2023, with only brief dips during La Niña phases. The probability of the global temperature increase by less than 1.10ºC in May reflects how far the recent monthly trend sits from that lower band. [Yahoo/Reuters, May 28]

The structural drivers behind the elevated baseline include sustained record ocean heat content, reduced sulphate aerosol loading from shipping fuel regulations, and the residual heat from the 2023–2024 El Niño event. The WMO report further warns of compounding regional impacts, including accelerated Arctic ice loss and a dangerous drought outlook for the Amazon, described as a crucial natural carbon sink. Resolution of whether the global temperature increase by less than 1.10ºC in May 2026 is achieved will depend on the official Copernicus ERA5 and NASA GISTEMP monthly bulletins released in early June, which historically publish within the first two weeks of the following month. [Houston Chronicle, May 28]

Traded on Polymarket — $52K Volume

Lower-volume market on Polymarket ($52K). Wider spreads expected — enter with limit orders and be aware of slippage risk. Currently 10c YES.