Weather experts have revealed last month was the joint warmest month ever recorded, tied with July 2023, amid warnings over the impact of fossil fuels and a potentially extreme El Niño event.

The Copernicus Climate Change Service (C3S), implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF) added August also saw the average sea surface temperature (SST) over the extra-polar ocean reach a record high, due to global heating from burning fossil fuels and rapidly increasing SSTs in the equatorial Pacific associated with strong El Niño conditions.

With a global average surface air temperature 1.65°C higher than the estimated pre-industrial baseline, this August was the first month to exceed 1.5°C since November 2025. The month saw the joint highest monthly average SST ever recorded across the extra-polar ocean*, tied with March 2024, and the highest daily global SST over the extra-polar ocean ever recorded, at 21.11ºC. Meanwhile, record high SSTs were seen across the tropical Pacific, an area where a potentially extreme El Niño event continues to intensify. The impacts of this event are already being felt over land, with conditions favouring the intensification of seasonal wildfires across Indonesia, as reported by the Copernicus Atmosphere Monitoring Service (CAMS).

The month marked the end of western Europe’s warmest summer on record, surpassing the previous record set in 2003. The region also saw further heatwaves in August, continuing an exceptional run of extreme heat that began in May. Much of the region and large parts of central and eastern Europe also saw widespread dryness in August, in some cases persisting since May, with severe drought conditions reported in France, the UK, Hungary, Romania and Serbia. Across the dry regions, major European river flows were exceptionally low, including – from west to east – the Rhine, Danube, Southern Bug and Dnieper experiencing exceptionally low flows.

“August 2026 was a remarkable month in the global climate record,” explained Samantha Burgess, strategic lead for climate at ECMW,. “It was both the warmest August and the warmest month ever recorded, with global temperatures reaching 1.65°C above pre-industrial levels, marking the return of global temperatures above 1.5°C. Combined with record global sea surface temperatures and the warmest summer on record for Western Europe, these observations show how climate change is driving extremes across both the atmosphere and the oceans. The impacts of these conditions are increasingly being felt by communities, economies and ecosystems across the world.”
The organisation reported:

• The global-average surface air temperature in August 2026 was 16.96°C, 0.85°C above the 1991–2020 average, making it the warmest August globally in the ERA5 dataset, surpassing the previous joint record set in 2023 and 2024.
• August 2026 was also the joint-warmest month ever recorded globally across all calendar months, on par with July 2023.
• The period from June to August 2026 was the joint-warmest on record globally, on par with 2024.

Europe’s surface air temperature created a new record:

• The average temperature over European land in August 2026 was 20.26°C, 1.10°C above the 1991-2020 average for the month, making it the fourth-warmest August on record.
• Summer 2026 (June to August) was the third warmest on record for Europe, behind 2024 and 2022.
• Western Europe experienced its warmest summer on record, surpassing the long-standing 2003 record. The 2026 season was marked by a succession of exceptionally early, persistent and intense heatwaves across the region.

Sea surface temperatures (SSTs)

• The average SST for extra-polar oceans (60°S–60°N) in August 2026 was the highest on record for the month, at 21.07°C, surpassing the previous August record of 20.98°C set in 2023.
• The average extra-polar SST for August 2026 was also the joint highest on record across all calendar months, on par with March 2024.
• SSTs remained exceptionally high across much of the tropical Pacific, where El Niño conditions are present and forecast to further strengthen in the coming months, potentially into one of the strongest El Niño events on record.
• Around Europe, SSTs reached record highs for August along the Atlantic coast and in the western Mediterranean, associated with widespread strong or severe marine heatwave conditions.

On the European summer C3S said: “In summer 2026, conditions were much drier than average in western and central Europe, southern Scandinavia and southeastern Europe. The precipitation deficit, more pronounced over the western regions in June, progressively shifted eastward during the season.

“Severe impacts of these conditions included widely reported exceptional drought and wildfire activity and related emissions.  In contrast, western Iberia, southern Greece, southern Türkiye and Cyprus, as well as northeastern Europe, were wetter than average.

“For the season as a whole, much of continental Europe saw lower than average river flow. Large stretches of the Seine, Rhône, Loire and Glomma recorded their lowest seasonal flows since the beginning of the data record in 1992, with record-low conditions extending along the entire length of the Danube, Vistula and Rhine.”