May 2025 was the planet's 2nd-warmest on record: Copernicus
Last month was the second-warmest May on record globally, trailing only the previous May, according to new data analyzed by the Copernicus Climate Change Service (C3S). And in the Northern Hemisphere, spring also ranked as the second-warmest on record, again behind 2024.
Notably, May marked the first month since July 2024 in which the global average temperature did not exceed the 1.5-degree Celsius warming threshold established in the 2015 Paris Climate Agreement. Instead, it registered 1.40 degrees Celsius above the pre-industrial reference period (1850-1900). The Earth's average surface air temperature came in at 60.42 degrees Fahrenheit, or 15.79 degrees Celsius.
A short-term drop in global temperatures was anticipated due to the recent La Niña event in the equatorial eastern Pacific Ocean, a climate pattern that typically brings a temporary dip in global average temperatures. However, climate scientists caution that this pause is unlikely to last, as human-caused greenhouse gas emissions continue to fuel the long-term warming trend.

Global daily sea surface temperatures across much of the world's oceans remained well above average in May, with the second-highest value on record for the month, according to Copernicus.
Unusually warm sea surface temperatures across portions of the Atlantic Basin could play a key role in tropical cyclone development during the Atlantic Hurricane Season, which is now underway. The National Oceanic and Atmospheric Administration (NOAA) predicts that Atlantic tropical cyclone activity will likely be above average this year, citing elevated ocean temperatures as a contributing factor.
-ABC News meteorologist Dan Peck