The sea surface did something it had never done in the record: in August, the daily global sea surface temperature outside the polar regions hit 21.11°C, the highest ever observed. It was one marker in a month that three agencies agree was the hottest August on record.
The World Meteorological Organization (WMO) pointed to reports from the EU’s Copernicus Climate Change Service, the US National Oceanic and Atmospheric Administration (NOAA) and NASA. Copernicus put the global average surface air temperature at 1.65°C above the estimated pre-industrial level. Its ERA5 data showed August tied with July 2023 as the joint warmest month ever recorded. NOAA’s figure was 1.32°C (2.38°F) above the 20th-century average, the warmest August in a record that starts in 1850. All ten of the hottest Augusts have come since 2016.
Oceans, ice and storms
The Northern Hemisphere had its warmest summer on record, and the Southern Hemisphere a near-record warm winter. Both the Arctic and Antarctic ended August with below-average sea ice. Marine heatwaves, strong or severe in places, hit the Atlantic coast of Europe and the western Mediterranean.
Tropical cyclones ran above average, with 19 tropical storms. Five reached hurricane or typhoon strength and four of those were major. The pattern differed by basin. The Atlantic was unusually quiet, with two weak, short-lived storms, while warm water in the eastern tropical Pacific helped fuel eight named storms in the Eastern North Pacific. Typhoon Dolphin was the strongest storm of the season to make landfall in China.
Europe baked, then dried
Western Europe had more heatwaves, extending an exceptional run of extreme heat that began in May. Severe drought was reported in France, the UK, Hungary, Romania and Serbia, and large parts of central and eastern Europe stayed dry, in some cases since May. River flows were exceptionally low in the Rhine, Danube, Southern Bug and Dnieper.
El Niño is just getting going
“It is now firmly established and will intensify into a very strong event in the coming months, with big impacts on rainfall and temperature patterns well into 2027,” the WMO said, citing its latest El Niño Update. The agency gave a nearly 100% probability that El Niño lasts through February 2027, peaking toward the end of 2026.
It also issued a caution: how strong an El Niño is does not map directly onto how severe its effects are in a given region. This month it brought heavy rain and floods to some countries, and drought and worse wildfires to Indonesia. The WMO urged governments and disaster agencies to strengthen preparedness and early-warning systems.
The agency will present an updated climate assessment at COP31 in Antalya, Turkey, in November.
Sources
- Earth records hottest August as El Niño intensifies – Channel Africa
- Earth has hottest August on record
