May 2026 was the second warmest ever recorded globally for land and sea, the Copernicus Climate Change Service (C3S), implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF), reported.
The ERA5 record shows May 2026 was the second warmest May on record, with an average surface air temperature of 15.81°C, or 0.55°C above the May 1991-2020 average, only surpassed by May 2024. This was 1.42°C higher than the estimated average for 1850–1900, before industrialisation.
The average May 2026 SST (sea surface temperature) in the 60°S-60°N band was tied for the second warmest on record for the month at 20.90°C, behind May 2024 (20.93°C).
