August 2026 officially matched July 2023 as the world's hottest month on record, with global average surface air temperatures soaring to 1.65°C above pre-industrial levels. This unprecedented heat coincided with Western Europe experiencing its warmest summer ever, marked by widespread drought and exceptionally low river flows across several nations.
Global Temperatures Reach Critical Thresholds
According to the Copernicus Climate Change Service (C3S), the global average surface air temperature in August 2026 reached 16.96°C, representing an increase of 0.85°C compared to the 1991–2020 average. Notably, August was the first month since November 2025 where global temperatures consistently exceeded the crucial 1.5°C threshold above the estimated 1850–1900 pre-industrial baseline.
While a single month's breach does not signify a permanent exceedance of the Paris Agreement's long-term warming limit, it underscores a clear pattern of persistently warmer global climates and an escalating frequency and intensity of temperature extremes worldwide.
Oceans Experience Record Warming
The warming trend extended significantly into the world's oceans. The average sea surface temperature (SST) over extra-polar oceans (between 60°S and 60°N) hit an unprecedented 21.07°C in August, surpassing the previous August record set in 2023. This figure also tied with March 2024 as the highest recorded for any calendar month, with a daily global SST peaking at 21.11°C.
Compounding these concerns, El Niño conditions continued to intensify across the tropical Pacific. C3S projections indicate a further strengthening of El Niño in the coming months, potentially leading to one of the most powerful events on record. The combined effect of global warming and these unusually warm Pacific waters is already impacting weather patterns, including contributing to increased seasonal wildfire activity in regions like Indonesia.
Western Europe's Hottest Summer on Record
Europe endured particularly severe heat throughout the June-August 2026 period. Western Europe, in particular, recorded its warmest summer ever, surpassing the previous record established in 2003. The region experienced a succession of exceptionally early, persistent, and intense heatwaves that began as early as May.
Widespread dryness characterized much of western, central, and eastern Europe through August. Countries like France, the UK, Hungary, Romania, and Serbia reported severe drought conditions. This prolonged lack of moisture severely impacted major river systems, with the Rhine, Danube, Southern Bug, and Dnieper all recording exceptionally low flows. Other significant rivers, including the Seine, Rhône, Loire, and Glomma, also experienced unusually low seasonal water levels.
However, the climate extremes were not uniform; parts of western Iberia, the Alpine region, northeastern Europe, and eastern Türkiye experienced wetter-than-average conditions, leading to localized heavy rainfall and flooding.
A Broader Warning from 2026 Data
Globally, the June-August 2026 period collectively stood as jointly the warmest summer on record, matching 2024. The comprehensive data—encompassing temperature, ocean conditions, and hydrological indicators—paints a clear picture of a global climate system grappling with increasingly pronounced extremes. C3S observations from August highlight how climate change is intensifying these extremes across both atmospheric and oceanic domains, with growing consequences for communities, economies, and ecosystems worldwide.