August 2026 was Earth’s equal warmest month on record, with a global mean surface air temperature 1.65°C above the pre-industrial average.

According to data from the European Union’s Earth Observation Programme – Copernicus – the average global surface air temperature in August 2026 was 16.96°C. This was 0.85°C above the 1991–2020 average and 1.65°C above the pre-industrial 1850–1900 baseline. This was the planet’s warmest August on record, and the equal warmest month on record, on par with July 2023 in the Copernicus dataset.

Ocean temperatures also broke records in August. Earth’s extra-polar oceans – those between 60°S and 60°N, which is most of the world’s oceans excluding waters near the poles – had an average sea surface temperature of 21.07°C last month. This beat the previous August record of 20.98°C from 2023 and matched the any-month record from March 2024.

Why was it so warm in August?

Last month’s record-breaking warmth in the atmosphere and ocean was caused by the combined influence of climate change and El Niño.

Climate change is making Earth’s oceans warmer. According to data from the Bureau of Meteorology, the average sea surface temperature for Earth’s extra-polar oceans in August increased by 1.14°C between 1900 and 2026.

On top of this background warming trend, a strengthening El Niño has caused abnormally warm water to build up in the tropical Pacific Ocean in recent months. In August, temperatures in the central and eastern tropical Pacific were around 2.5 to 3 °C warmer than average. These exceptionally warm waters associated with El Niño likely contributed to elevated global sea surface temperatures in 2026.

Increasing likelihood that 2026 will be Earth’s warmest year on record The rapid pace at which El Niño has developed in recent months has increased the likelihood that 2026 will become the warmest year on record based on global air temperature.

In mid-August, Berkeley Earth gave a 69% chance that 2026 would become Earth’s warmest year on record. This was up from 12% the previous month.

August's exceptional warmth may increase the likelihood of 2026 becoming the warmest year on record. Updated estimates will be available from Berkeley Earth later this month.