The world has just seen its third warmest September on record, with both land and sea surface temperatures staying unusually high, according to the EU’s climate monitoring network.

The Copernicus Climate Change Service (C3S) reported that the global average surface temperature in September this year was 16.11°C. This is slightly lower than the same month in 2023 and 2024 by 0.27°C and 0.07°C, respectively, but remains 1.47°C above pre-industrial levels, according to Xinhua.

C3S data shows that the global average sea surface temperature in September reached 20.72°C, marking the third-highest level for this month on record. Most of the North Pacific experienced sea surface temperatures well above the long-term average, with some regions hitting record highs.

Meanwhile, sea surface temperatures in the central and eastern equatorial Pacific were close to or below the 1991–2020 average, reflecting a neutral phase of the El Niño–Southern Oscillation.

The report also noted that Arctic sea ice extent for the month was 12% below the long-term average, while Antarctic sea ice was 5% below the average.

Samantha Burgess, strategic lead for climate at C3S under the European Centre for Medium-Range Weather Forecasts, said that September 2025 ranks as the third warmest September on record, trailing September 2024 by less than 0.1°C.

“Compared to last year, global temperatures remain largely unchanged, with persistently high land and sea surface temperatures underscoring the ongoing impact of accumulated greenhouse gases in the atmosphere,” she added.