The UK's climate has been fundamentally rewritten in just two decades. Gone are the weather patterns of the 20th Century – now relegated to a bygone era. The Met Office warns that what was once considered extreme is rapidly becoming the new normal, putting immense pressure on Britain's infrastructure and public health.
2025 marked the warmest year on record since data collection began in 1884, with temperatures soaring an average of 1.33C above the 1961-1990 baseline over the past decade. This modest rise has a significant impact: the hottest day of the year in southern England is now typically 4.5C warmer than it was between 1961 and 1990.
Met Office climate scientist Mike Kendon notes that Britain's climate is "on the move," with northern regions experiencing temperatures once reserved for southern England. The warming trend is also affecting higher altitudes, leading to the loss of habitats at mountain summits. Areas like the Vale of York and Lancashire now enjoy temperatures comparable to Greater London in the 1961-1990 period.
The report highlights the severe consequences of these changes, particularly during heatwaves. This summer has seen a plethora of homes, schools, hospitals, and transport networks struggling to cope with successive periods of high temperatures. In Greater London, for instance, there's been a more than quadrupling of days exceeding 30C and nights above 18C in the 2016-2025 period compared to 1961-1990. Estimates from experts at Imperial College London, the Met Office, and the London School of Hygiene and Tropical Medicine suggest over 2,700 heat-related deaths in England and Wales during the exceptionally hot May and June of 2026.
Water availability and drought frequency have also been examined in the report. Spring 2025 saw most of England and Wales receive less than half their average rainfall for 1991-2020 – marking England's driest spring in over a century. This led to river flows across England from March to August 2025 being the second lowest since 1961, resulting in drier-than-average soils, stunted plant growth, impacts on food production, and increased wildfire risks.