2025 Kicks Off With Warmest January on Record

January 2025 was the warmest January on record, according to data from the EU Copernicus Climate Change Service. The data has surprised scientists, who predicted that this January would be at least slightly cooler on average than January 2024 now that the El Niño weather pattern has ended and the cooling La Niña weather pattern is emerging.

But Copernicus Climate Change Service data revealed that last month reached an average air surface temperature of 13.23 degrees Celsius (approximately 55.8 degrees Fahrenheit). This is about 0.09 degrees Celsius warmer than January 2024, the previous hottest January on record, NBC San Diego reported. Further, the data showed that January 2025 was about 1.75 degrees Celsius warmer than average January temperatures from pre-industrial times.

An El Niño event that lasted from summer 2023 well into spring 2024 exacerbated higher temperatures in 2024, leading scientists to believe that January 2025 would bring cooler air and sea surface temperatures. With a cooling La Niña starting up in early 2025, scientists have been left surprised by the record-high air temperature for January.

January 2025 was the warmest January ever recorded. Last month was 1.75°C above the pre-industrial level and 0.79°C above the 1991-2020 average. The persistence of high temperatures underscores significant climate trends. Read the full #C3S Climate Bulletins: bit.ly/3EBUTD1

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— Copernicus ECMWF (@copernicusecmwf.bsky.social) February 6, 2025 at 4:14 AM

“If you’d asked me a few months ago what January 2025 would look like relative to January 2024, my best shot would have been it would be cooler,” said Adam Scaife, head of Monthly to Decadal Prediction at the UK Met Office, as reported by the BBC. “We now know it isn’t, and we don’t really know why that is.”

Sea surface temperatures were also higher than expected, although they just barely missed the record for highest January sea surface temperatures. The average sea surface temperature for 60°S–60°N latitudes was 20.78 degrees Celsius, which was only 0.19 degrees Celsius below the record set in January 2024.

“January 2025 is another surprising month, continuing the record temperatures observed throughout the last two years, despite the development of La Niña conditions in the tropical Pacific and their temporary cooling effect on global temperatures” said Samantha Burgess, strategic lead for climate at the European Centre for Medium-Range Weather Forecasts (ECMWF).

With the rising temperatures, Arctic sea ice also hit a monthly low for January, reaching about 6% below the average sea ice levels, Copernicus Climate Change Service data revealed. In the Antarctic, sea ice was 5% below average but did not reach the record or near-record lows of sea ice found in 2023 and 2024.

According to the Copernicus Climate Change Service, La Niña is still in development. But even if it peaks this year, the phenomenon won’t be enough to lower global average temperatures.

“By far and away the largest contributing factor to our warming climate is the burning of fossil fuels,” Burgess said, as reported by NBC News.

In January, the Copernicus Climate Change Service estimated that 2024 would be the warmest year on record, and last year was the first calendar year to breach an average global temperature that was 1.5 degrees Celsius higher than pre-industrial times.

“Copernicus will continue to closely monitor ocean temperatures and their influence on our evolving climate throughout 2025,” Burgess said in a statement.