This summer has felt particularly warm and humid across the UK, prompting many to ask: is this just a typical British summer, or is something more unusual going on?
Looking at the data, it’s clear this is not just business as usual. June 2025 was exceptionally warm. That warmth has continued into July, with mean temperatures placing this summer so far in the top 5% of all summers on record.
Night-time temperatures have been especially notable, exceeding previous records for this stage of the season. By the end of the recent hot spell, temperatures of 30°C or more had been recorded on 11 separate days, something that has only happened twice before, in 1976 and 2018.
What’s driving the heat?
Several factors are contributing to the current warm spell. One is the condition of the ground. While overall summer rainfall has been close to average across the UK, it followed a very dry spring. Much of England, Wales, and parts of eastern Scotland received less than 50% of average rainfall during spring, with some areas seeing less than 30%. This has led to high soil moisture deficits, particularly in parts of Wales, the West Midlands, and Yorkshire.
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Dry ground heats up more quickly than moist soil. When soil is wet, some of the sun’s energy goes into evaporating moisture. When it’s dry, more of that energy goes directly into heating the air, contributing to higher temperatures.
Another factor is sea surface temperature. The seas surrounding the UK are currently significantly warmer than average, with a marine heatwave affecting parts of southern England, South Wales, and the Irish Sea. This warm water helps to keep the air temperatures elevated, especially when winds bring air in from over the sea.
Persistent high pressure has also played a role. High pressure systems suppress cloud formation and trap warm air near the surface, allowing temperatures to build day after day under strong sunshine.
Finally, the background influence of climate change. The UK, like the rest of the world, is warming. This long-term trend increases the likelihood of hotter summers and more frequent heatwaves.
Why does it feel so humid?
Have you been one of the many people wondering if the heat this summer feels different? More oppressive, more draining. That’s because it’s not just hot, it’s also humid.
Humidity refers to the amount of water vapour in the air. The UK, being a group of islands, is naturally more humid than many inland areas. But with sea temperatures currently elevated, the air masses moving over the UK are carrying even more moisture than usual.
Humidity affects how we experience heat. When the air is humid, sweat evaporates less efficiently, making it harder for our bodies to cool down. This can lead to heat stress, dehydration, and in extreme cases, heatstroke. Vulnerable groups such as the elderly, young children, and those with pre-existing health conditions are particularly at risk.
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As the climate continues to warm, the atmosphere will be able to hold more water vapour, increasing the likelihood of both extreme heat and high humidity. This has implications not just for comfort, but for public health, infrastructure, and the environment.
The Met Office, in collaboration with international partners, is monitoring these changes closely through datasets such as HadISDH, which track humidity trends over land and sea. Understanding how heat and humidity interact is essential for preparing for future extremes.
This summer is a clear reminder that climate change is not a distant threat, it’s happening now, and it’s reshaping the weather we experience day to day.
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