The Met Office has issued an Amber extreme heat warning for much of southern England and southeastern Wales, with impacts to people and infrastructure possible at the start of next week and water safety a particular concern.

A heatwave, centred around southern and eastern England initially, is developing over the weekend and will continue into the start of next week. The Amber extreme heat warning coincides with what is expected to be the peak of the heat through Monday and Tuesday, when temperatures are likely to reach 34°C – the Met Office is warning there remains a chance of this being exceeded in some spots.

The current highest temperature on record for June is 35.6°C and there remains a chance of this figure being challenged at the start of next week.

Met Office Deputy Chief Forecaster Greg Wolverson said:

“While heatwave criteria will be met for some in the south and southeast of England over the weekend, with temperatures into the low 30s Celsius possible, the warmth will expand and intensify at the start of next week, which, coupled with high temperatures overnight, leads to potential impacts.

“Temperatures will peak around the mid-30s Celsius on Monday and Tuesday. The humidity will also mean this feels close, warmer and more uncomfortable for many. Tropical nights – where the temperature doesn’t drop below 20°C are also likely for some.”

The heatwave will regress from the middle of next week, though those in the south and east are likely to hold on to the warmth the longest.

The warning highlights potential health impacts for those vulnerable to extreme heat, as well as the potential for heat-related issues for the wider population. A combination of higher humidity and temperatures remaining high overnight exacerbate health impacts.

An increase in potential water safety incidents is also noted, as more people are likely to visit coastal areas, lakes or rivers.

The UK Health Security Agency has also issued a series of Heat Health Alerts, which specifically highlight the potential health and social care impacts