September 2026 Was the Second-Warmest on Record, With Global Temperatures Above 1.5°C for a Second Month

September 2026 was the second-warmest September in the ERA5 global dataset, with an average surface air temperature of 16.27°C—0.82°C above the 1991–2020 average. It was 1.63°C above the estimated pre-industrial level, marking the second consecutive month above 1.5°C. The monthly threshold is not the same as breaching the Paris Agreement’s long-term warming limit. Copernicus says intensifying El Niño conditions could keep temperatures unusually high into 2027. September was also Europe’s third-warmest on record and western Europe’s joint-warmest.