Amber heat warning as UK temperatures climb to 35C by Tuesday

A short pause in the heat is giving way to a sharper surge, with temperatures set to climb again and an amber extreme heat warning now covering much of southern England and southeastern Wales. The Met Office warned that impacts to people and infrastructure are possible at the start of next week, as the country moves from a slightly cooler Saturday into a hotter spell that could push readings to 35C by Tuesday.

The warning also puts water safety in the spotlight. The Met Office says more people are likely to head to coastal areas, lakes and rivers during the hot spell, increasing the risk of incidents. It also said tropical nights are likely in some areas, meaning temperatures may not fall below 20C overnight and offering little relief for people trying to recover from daytime heat.

The warning was issued on Friday 19 June 2026, and the Met Office says the heatwave is expected to ease from the middle of next week. Even then, southern and eastern parts of the country are likely to hold on to the warmth for longer, leaving little room for complacency after the brief dip in temperatures.

In Sheffield, the heat is expected to build steadily rather than arrive all at once. The Met Office forecast shows around 25C on Monday 22 June and 32C on Tuesday 23 June, with the detailed hourly outlook peaking at about 31C later in the day. The city is not currently under a weather warning, and Yorkshire and the Humber is forecast to sit in the low-to-mid 20s across the region.

Health officials are treating the risk as seasonal but serious. The UK Health Security Agency says its heat-health alerting system runs from 1 June to 30 September each year, and its dashboard for Yorkshire and the Humber shows no alert in force. Even so, it lists minor possible impacts across health and social care, including increased demand from vulnerable people, warmer indoor environments and possible water-related incidents.

NHS advice remains clear: hot weather can cause dehydration, heat exhaustion and heatstroke, and the highest risk falls on babies, older people and people with long-term health conditions. Sheffield City Council says the city’s climate projection points to much hotter, drier summers and warmer winters, underlining why heat planning now matters as much as the forecast itself. Sheffield reached 39.4C in 2022, far above its previous maximum of 35.6C set in July 2019, and the next surge will test how well people, services and infrastructure can cope.