Unusual May warmth gripping the United Kingdom is set to escalate over the bank holiday weekend, with temperatures forecast to reach heatwave conditions in multiple areas. Daytime highs are expected to climb into the upper 20s Celsius across much of the country, with the potential for low 30s Celsius in the week following.

Friday marked the warmest day of the year so far, with London exceeding 28C (82.4F) and meeting the official heatwave threshold. The current heat is unusual for May, typically seeing average highs in the upper teens. Some locations may experience temperatures around 10 degrees Celsius higher than normal for this time of year.

The UK Health Security Agency has issued amber heat health alerts for the Midlands, eastern, and south-east England. These alerts signal a risk of significant impact on health and social care services, particularly for children and individuals over 65. The rest of England is under yellow heat health alerts, indicating that adverse weather conditions are likely to affect vulnerable populations.

Temperatures are predicted to continue climbing on Saturday, with the highest readings expected in central and southern England and parts of Wales. The Met Office notes that days exceeding 30C, termed 'very hot days,' have become significantly more frequent, more than tripling in number over the last decade compared to the 1961-1990 average. The last time temperatures reached 30C in May was in 2012.

By Sunday, the first heatwaves of 2026 are likely to be declared as several regions, including London, south-east England, and Cardiff, are expected to surpass the heatwave threshold for a third consecutive day. Locally, the south Midlands and south-east England could reach 30C on Sunday, a rare occurrence for May.

Bank holiday Monday holds the possibility of becoming the hottest May day on record for the UK, with forecasts suggesting temperatures could approach 33C in south-east England. This would surpass the previous May record of 32.8C, set on the Late May Bank Holiday in 1944. However, coastal areas on the east coast of England might experience mist, potentially moderating temperatures.

Looking ahead to Tuesday, Wednesday, and Thursday, temperatures are expected to rise across Scotland and Northern Ireland, which have seen cooler conditions. Glasgow could reach the low to mid-20s Celsius, and western Northern Ireland may also experience warmth approaching the mid-20s.

While natural weather variations exist, this early-season heat aligns with long-term trends of rising global temperatures attributed to human-caused climate change. Experts highlight that the duration of this heatwave, in addition to its intensity, is a notable characteristic.