August 2026 tied July 2023 as the hottest month ever recorded globally, as human-caused climate change combined with a strengthening El Niño to push temperatures to exceptional levels.

According to the European Union's Copernicus Climate Change Service (C3S), the global average surface air temperature reached 16.96°C during August, 1.65°C above the estimated 1850–1900 pre-industrial average.

The month was also the warmest August in the ERA5 climate dataset, exceeding the previous August records set in 2023 and 2024.

The reading pushed the monthly global temperature above 1.5°C over pre-industrial levels for the first time since November 2025. However, an individual month above that level does not by itself mean the Paris Agreement's 1.5°C goal has been breached, since the agreement refers to long-term global warming rather than a single month.

Oceans were exceptionally warm as well. The average sea-surface temperature across the extra-polar oceans reached 21.07°C in August, the highest recorded for the month and tied with March 2024 for the highest monthly value across the dataset.

Western Europe also experienced its warmest summer on record, surpassing the long-standing record from 2003. Persistent and intense heatwaves affected much of the region during the season.

Scientists say the long-term rise in global temperatures is primarily driven by greenhouse gas emissions from human activities, particularly the burning of fossil fuels.

El Niño adding to global temperatures

Alongside human-caused warming, a developing El Niño is providing an additional natural influence on global temperatures.

El Niño occurs when surface waters in parts of the central and eastern equatorial Pacific become unusually warm, affecting atmospheric circulation and altering temperature and rainfall patterns around the world.

The World Meteorological Organization said in its latest update that El Niño is now firmly established and is expected to strengthen further during the coming months.

Forecasts from WMO's global climate centres indicate a nearly 100% likelihood that El Niño will persist through February 2027. The organisation expects the event to reach very strong intensity before peaking towards the end of 2026.

A strong El Niño can shift rainfall and temperature patterns significantly, increasing the risk of extreme heat, drought and flooding in different parts of the world. Its effects are not uniform, however, and depend on interactions with other ocean and atmospheric conditions.

The combination of a strengthening El Niño and the continued rise in temperatures caused by greenhouse gas emissions means unusually high global temperatures could persist in the months ahead.