1569. August 2026 ties as the hottest month on record—global temperature 1.65°C above pre-industrial levels

On 10 September 2026, the European Union’s Copernicus Climate Change Service (C3S) announced that the global-average surface air temperature in August 2026 was 16.96°C, tying July 2023 as the hottest month on record across all calendar months. This was 0.85°C above the 1991–2020 average and 1.65°C above the estimated 1850–1900 pre-industrial average. It was the first month since November 2025 in which the monthly global-average temperature exceeded the pre-industrial level by more than 1.5°C. The sections below outline conditions in the oceans and the main regional features, including those in Europe and Japan.

According to C3S, the average sea surface temperature between 60°N and 60°S in August 2026 was 21.07°C, the highest value recorded for August. It also equalled the record for the highest monthly average across all calendar months in the dataset used by C3S, previously reached in March 2024. C3S attributed these exceptionally high sea surface temperatures to global warming caused by fossil-fuel combustion, together with rapidly rising sea surface temperatures and strengthening El Niño conditions in the equatorial Pacific. The Copernicus Atmosphere Monitoring Service (CAMS), a sister service of C3S, also reported that El Niño-related conditions were creating an environment conducive to more intense seasonal forest fires in Indonesia.

In Western Europe, the average temperature for summer 2026 (June–August) surpassed the previous record set in 2003, making it the hottest summer on record. C3S linked this record-breaking summer to an exceptionally early, persistent and intense heatwave that began in May.

In August 2026, drier-than-average conditions affected broad areas of Central and Eastern Europe as well as Western Europe. Although the August rainfall deficit in Western Europe had eased compared with early summer, surface soil moisture remained exceptionally low in dry areas, reflecting the effects of several preceding months of dryness. Severe drought was reported in France, the United Kingdom, Hungary, Romania and Serbia, while river flows were exceptionally low in the Rhine, Danube, Southern Bug and Dnieper. C3S also noted widespread reports of severe drought, the occurrence and spread of wildfires, and associated emissions across Europe during summer 2026.

For Japan, C3S identified the eastern edge of East Asia—including eastern China, Taiwan and Japan—as one of the regions that was wetter than average in August 2026. This indicates a regional pattern in monthly precipitation and does not imply uniform weather conditions across all of Japan.

The exceedance of 1.5°C above the pre-industrial level reported here refers to the global-average temperature for a single month. It therefore does not in itself mean that the long-term warming level associated with the Paris Agreement’s 1.5°C goal has already been exceeded.

At the same time, the UNEP report published in September 2026 and introduced in the recent Pick Up 1567 noted that, if the long-term global-average temperature rises above 1.5°C in an “overshoot,” risks to people and nature increase as the peak warming becomes higher and the period above 1.5°C becomes longer. The report indicated that impacts such as extreme heat, heavy rainfall, drought and ecosystem loss could intensify. It also highlighted the growing possibility of crossing thresholds that could trigger irreversible changes, or changes that would be extremely difficult to reverse on human timescales, as well as an increased likelihood of reaching the limits of adaptation.

Although the latest record does not itself demonstrate a long-term overshoot, it is an important observation showing that global temperatures have reached a stage at which the 1.5°C level may be met or exceeded repeatedly. It is therefore more important than ever to limit both the peak and duration of any overshoot through rapid and sustained reductions in greenhouse gas emissions, while strengthening adaptation measures to address impacts that are already emerging.

References

Copernicus Climate Change Service (C3S). (10 September 2026). “Copernicus: August was the world’s joint hottest month on record, pushing global temperatures back above 1.5°C above pre-industrial levels.” https://climate.copernicus.eu/copernicus-august-was-worlds-joint-hottes… (accessed 10 September 2026).

United Nations Environment Programme (UNEP). (2 September 2026). “Limiting Overshoot: Navigating exceedance of 1.5°C and pathways towards return.” https://www.unep.org/resources/limiting-overshoot-navigating-exceedance (accessed 13 September 2026).

Contributor: Miyuki IIYAMA, Strategic Coordination Office