The United Kingdom and continental Europe experienced two consecutive record-breaking heatwaves in May and June 2024, with temperatures departing from historical norms by unusually large margins. The UK recorded 37.7°C in Norfolk, surpassing the previous June high by over 2°C, while more than a dozen European countries similarly shattered their June records by gaps of 2–3 degrees. Scientists emphasised the extraordinary nature of such large breaks from previous baselines, noting that records are typically exceeded by only fractions of a degree.

The oppressive character of June's heat stemmed partly from concurrent high humidity that impaired the body's natural cooling mechanisms, combined with warm nights that prevented recovery—with Cardiff recording a historic 23.5°C minimum temperature. Experts linked these intensified events to human-driven climate change from fossil fuel emissions, cautioning that such conditions will likely intensify and occur more regularly as global temperatures continue to rise. Another heatwave was already forecast to follow the brief respite.