The United Kingdom experienced a "tropical night" on Monday, May 26, 2026, as temperatures failed to drop below 21.3°C [1].
This event marks a significant climatic anomaly for the region. The persistence of high overnight temperatures follows a heatwave that produced the hottest May day since the Met Office began its records [1].
The record-breaking minimum temperature of 21.3°C was recorded at Kenley airfield in south London [1], [2]. This result represents the second consecutive day that May temperature records were broken in the UK [2].
A tropical night is characterized by the daily minimum temperature remaining above 20°C. The current heatwave has pushed the UK's spring weather into territory typically associated with much warmer climates, a shift that has drawn attention from meteorologists.
While the Met Office focused on the overnight records, other reports indicated that the heatwave may continue. Some forecasts suggested that temperatures could reach 36°C on the following day [3].
The combination of an all-time high daytime temperature and a record-breaking tropical night suggests a high level of heat retention in the atmosphere. This pattern has led to an unprecedented stretch of warmth for the month of May in Britain [1], [2].
“The UK recorded its hottest May day since Met Office records began”
The occurrence of a tropical night in May is an extreme deviation from historical UK weather patterns. When minimum temperatures remain high overnight, it prevents the environment and human populations from recovering from daytime heat, which can exacerbate the health risks associated with heatwaves. This trend of consecutive record-breaking days in May indicates a potential shift in seasonal temperature volatility.
