How does 2025 heatwave compare to record-breaking summer of 1976?

Much of England is now in its fifth day of a heatwave, with Tuesday (1 July) expected to be hotter than holiday spots such as Barbados, Jamaica, and Mexico. A heatwave is officially declared when temperatures reach set thresholds for three consecutive days, ranging from 25C to 28C depending on the region. The Met Office says temperatures could reach 35°C on Tuesday in London and the southeast, making it the hottest day of the year so far and just shy of the UK’s all-time June record from 1976. That summer was the hottest in over 350 years and the driest in 200. UN Secretary-General António Guterres has said: "Extreme heat is no longer a rare event – it has become the new normal."