The UK is currently experiencing its third heatwave of 2025, a year that has already set numerous weather records. Spring 2025 was the warmest and sunniest on record, followed by June, which became the hottest month ever recorded for England. With temperatures soaring, the country is grappling with the implications of climate change as it faces unprecedented heat.

According to the Intergovernmental Panel on Climate Change (IPCC), human activities have unequivocally warmed the atmosphere, ocean, and land. This rise in temperatures has significantly increased the frequency of extreme weather events, including heatwaves. The current heatwave is raising questions about whether this is merely a seasonal occurrence or a sign of more severe climate impacts.

Data from the Met Office indicates that spring 2025 saw temperatures averaging 1.4°C above the long-term norm. The highest temperature recorded so far this year was 35.8°C in Faversham, Kent, on 1 July. While this is below the UK's record high of over 40°C set in July 2022, the trend of increasingly frequent extreme heat days is evident.

Climate scientist Professor Ed Hawkins from Reading University explains that a global temperature rise of 1°C does not translate to a mere 1°C increase in heatwaves. He states, "Over large parts of the UK, global warming means that heatwaves are 3-4°C warmer." This significant increase is attributed to the vast amounts of heat energy required to elevate the Earth's average temperature.

The oceans play a crucial role in regulating the climate, absorbing over 90% of the excess heat trapped by greenhouse gases. However, the ability of oceans to stabilise the climate is under threat as marine heatwaves become more common.

The current weather patterns may also be influenced by the El Niño phenomenon, which typically raises global temperatures by approximately 0.1°C. Historically, many of the hottest years have coincided with El Niño events. However, climate scientists from NOAA assert that the effects of El Niño and La Niña are now overshadowed by the broader impacts of global warming. They note that recent La Niña years have recorded higher global average temperatures than earlier El Niño years.

As the UK endures this heatwave, the historical context of extreme temperatures, such as the infamous heatwave of June 1976, is being revisited. The ongoing weather patterns are prompting discussions about the long-term implications of climate change and the need for urgent action.