2025 Likely to Tie for Second-Hottest Year on Record

2025 Likely to Tie for Second-Hottest Year on Record

By Andrea Thompson edited by Claire Cameron

This year may be the second-hottest year on record, likely tying for silver with 2023. Europe’s climate agency on Monday reported that 2025 is slightly less scorching than 2024—which was the first year to exceed 1.5 degrees Celsius above preindustrial levels.

The European Union’s Copernicus Climate Change Service (C3S) reported data up to November 2025 that show this year has been 1.48 degrees C above the average from 1850 to 1900. That’s right around the target set by the 2015 Paris climate agreement, under which countries pledged to limit warming to below 1.5 degrees C and “well below” 2 degrees C. Despite 2024’s record-setting temperatures and 2025’s proximity to the 1.5-degrees-C threshold, scientists must take into account many years of data before they can say with certainty that the Paris Agreement’s target has been breached.

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Still, trends are heading that way. “The three-year average for 2023–2025 is on track to exceed 1.5°C for the first time,” Samantha Burgess, C3S’s strategic lead for climate, said in a statement. “These milestones are not abstract—they reflect the accelerating pace of climate change and the only way to mitigate future rising temperatures is to rapidly reduce greenhouse gas emissions.”

Record heat has become far more likely than record cold. Each of the world’s 10 hottest years have occurred within the last decade. The new temperature report comes just weeks after this year’s United Nations meeting to uphold the Paris Agreement ended with countries avoiding mention of fossil fuels, disappointing climate scientists and advocates who had hoped for stronger pledges to bring down planet-warming emissions.

That 2025 was so hot is particularly worrisome because this was a La Niña year. The opposite of an El Niño climate pattern, La Niña typically cools Pacific Ocean waters and leads to slightly colder global temperatures. But this year’s La Niña was weak and short-lived. Indeed, La Niña years are becoming hotter than some past El Niño years. Thanks to El Niño, 2016 was the hottest year on record at the time, but compared with 2025, “2016 is now looking decidedly cool,” said Adam Scaife of the U.K.’s Met Office in a news release issued by the agency last December.

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