Near-record warm May and March–May for the globe; below-average sea ice extent across both poles
May Highlights:
- May and March–May were much warmer than normal for the globe.
- Global land average precipitation in May was record high, according to preliminary data.
- Northern Hemisphere snow cover extent was below-normal for the month.
- Sea ice extent was below average for both poles.
- Global tropical cyclone activity was below normal with two named storms.
Temperature
Globally, May 2025 was the second-warmest May in NOAA’s 176-year record, with a temperature 1.98°F (1.10°C) higher than the 20th-century baseline. This is 0.14°F (0.08°C) cooler than the record set last May (2024). According to NCEI’s Global Annual Temperature Outlook, it is very likely that 2025 will rank among the five warmest years on record, with less than a 1% chance of ranking as the warmest year on record.
May temperatures were above average across much of the globe’s surface, in particular across most ocean areas and parts of every continent. Warm temperature departures were most notable in northern North America, the central and southern parts of South America, the British Isles and surrounding ocean, northern and southwestern Asia and across much of the Arctic and Antarctic regions. Pockets of below-average temperatures were present across parts of Alaska, eastern Europe, India and Antarctica.
Regionally, North America, South America, Asia, Africa and the Arctic all saw their May temperature rank among the 10 highest on record. Europe, Oceania and the Antarctic region also had above-average May temperatures, although they did not rank among the 20 warmest on record. India, parts of the northern Atlantic Ocean, the eastern and southeastern Pacific Ocean, central and eastern Europe and eastern Antarctica had May temperatures that were below average.
Globally, the March–May 2025 surface temperature was the second-highest in NOAA’s 176-year record, just behind the record set in 2024. This three-month period, defined as meteorological spring for the Northern Hemisphere and autumn in the Southern Hemisphere, was also the second warmest on record for both hemispheres individually.
Precipitation
May saw varied precipitation patterns globally. Many regions experienced drier-than-average conditions, including parts of North and South America, as well as northern Europe, southwestern Asia, southern Australia and areas in Russia and China. Southern Alaska, the eastern U.S., northern and southern parts of South America, northern and southeastern Australia and widespread parts of Asia had wetter-than-average conditions. Preliminary data indicate that the May 2025 globe land, averaged as a whole, had the wettest May in the historical record, which spans from 1979 to present.
Snow Cover
The Northern Hemisphere snow cover extent was the 15th-smallest May extent on record, with 370,000 square miles below average. Snow cover over North America and Greenland was below average by 200,000 square miles and was the 10th-smallest snow cover extent in the 59-year record. Eurasia was also below average by 170,000 square miles–the 16th-smallest extent for May. Below-normal snow cover was observed over Canada, parts of the Rockies in the United States and northern parts of Eurasia, as well as a band from western Mongolia through western China.
Sea Ice
Global sea ice extent was 550,000 square miles below the 1991–2020 average, ranking as the fifth-smallest May extent in the historical record. Arctic sea ice extent was also below average by 140,000 square miles, tying with 2004 as the seventh-smallest extent in the 47-year record. The Barents, Okhotsk and Bering Seas had lower than normal sea ice extent. The Antarctic sea ice extent was the fifth-smallest for May at 410,000 square miles below average.
Tropical Cyclones
Globally, tropical cyclone activity was below normal during May, with only two named storms. Neither storm reached tropical cyclone strength. One storm formed in the East Pacific basin, while the other formed in the Australian region.
For a more complete summary of climate conditions and events, see our May 2025 Global Climate Report or explore our Climate at a Glance Global Time Series.
