May 2026 Ranks as Second-Hottest Globally, EU Climate Monitor Reports

May 2026 was recorded as the second-hottest May in history, with Western Europe experiencing a heatwave that arrived earlier than usual, according to the European Union’s climate monitoring service on Wednesday (10/6).

The Copernicus Climate Change Service (C3S) stated that the global average surface air temperature in May 2026 reached 15.81 degrees Celsius, or 0.55 degrees Celsius above the 1991-2020 average. That figure ranks second only to May 2024 and is 1.42 degrees Celsius above estimated pre-industrial levels.

The average sea surface temperature between 60 degrees south latitude and 60 degrees north latitude hit 20.90 degrees Celsius, the second-highest record for May, as the tropical Pacific continues its transition towards El Niño conditions, which are predicted to develop in the coming months.

Western Europe was struck by an intense, early-arriving heatwave in the second half of May, with France, the United Kingdom, Ireland, Spain, and Portugal breaking numerous local temperature records. In some areas, the feels-like temperature reached 35 to 40 degrees Celsius.

"In Europe, the intense and early heatwave proves how quickly extreme climate phenomena are turning into a new normal, no longer an exception," said Samantha Burgess, Climate Strategy Lead at the European Centre for Medium-Range Weather Forecasts.

C3S noted that the sustained warming trend, combined with persistently high ocean temperatures and the emergence of El Niño conditions, highlights the increased risk of more frequent and intense extreme climate phenomena worldwide.