The UK recorded its highest daily minimum temperature for May during the night of May 30, 2024 [1].
This event marks a significant shift in seasonal weather patterns. The occurrence of a "tropical night" indicates that the environment failed to cool down overnight, which can exacerbate the physical stress of a heatwave on residents and infrastructure.
The Met Office said the minimum temperature reached 21.3°C [1]. This record was reported on May 31, 2024, following a period of intense heat across the country [2].
High readings were reported in several regions, with south-west London specifically noted as a hotspot [3]. At Kew Gardens, the maximum temperature on the same day reached 34.8°C [3].
The extreme conditions were driven by a prolonged heatwave that pushed daytime temperatures above 30°C [4]. This sustained heat prevented the typical nocturnal cooling process, a phenomenon that led to the classification of the event as a tropical night [4].
Such temperature spikes in late spring are rare for the region. The combination of record-breaking daytime highs and an unprecedented overnight minimum highlights the intensity of the atmospheric pressure system that stalled over the UK during that period [1], [2].
“The UK recorded its highest daily minimum temperature for May”
The emergence of 'tropical nights' in the UK suggests a trend toward more extreme temperature volatility in the spring. When overnight temperatures remain high, the human body and urban environments cannot recover from daytime heat, increasing the risk of heat-related illness and placing higher demands on energy grids for cooling.
