Earth experienced its hottest August on record, according to monthly reports from the EU's Copernicus Climate Service, the US National Oceanic and Atmospheric Administration and NASA, the World Meteorological Organization said in a report published on 11 September 2026. The Northern Hemisphere had its warmest summer, from 1 June to 31 August 2026, while the Southern Hemisphere saw a near-record warm winter.

Global sea surface temperature reached an all-time observed high in August, with El Niño conditions fuelling record temperatures across large areas of the central and eastern tropical Pacific Ocean. Arctic and Antarctic sea ice extent was below average. Copernicus ERA5 data showed August was the joint warmest month ever recorded, tied with July 2023, with global average surface air temperature 1.65°C above the estimated pre-industrial baseline. NOAA said the August 2026 global surface temperature was 2.38°F (1.32°C) above the 20th-century average, the warmest August in the 1850–2026 record.

WMO said El Niño was firmly established and would intensify into a very strong event in the coming months, with impacts on rainfall and temperature patterns well into 2027. Global tropical cyclone activity was above average in August, producing 19 tropical storms, of which five reached hurricane or typhoon intensity. Western Europe saw further heatwaves, and severe drought conditions were reported in France, the UK, Hungary, Romania and Serbia.