The warning, issued by the UK Health Security Agency (UKHSA) with the Met Office, covers the East Midlands, South East, East of England and London. It will be active from 9am on Wednesday until 9am on Thursday as forecasters predict a brief period of high temperatures.
The alert means significant impacts are likely, including possible pressure on vulnerable groups, health services and water safety. According to the UKHSA, hot weather can raise the risk of heart attacks, strokes, lung problems and other illnesses, particularly among older people, babies and young children.
Temperatures Expected to Peak in South-East England
The Met Office has forecast a rapid rise in temperatures during the first half of the week, with Wednesday expected to bring the highest values. Maximum temperatures of 35C are possible across south-eastern England, while much of England, Wales and eastern Scotland are expected to experience dry and sunny conditions.
Met Office Deputy Chief Forecaster Gregory Wolverson said the heat would be short-lived but that temperatures would climb quickly, especially in the south-east. “By Wednesday, some areas could see temperatures in the mid-30Cs, and while the heat will not be widespread across the whole of the UK, it will be enough for parts of the southeast to likely meet official heatwave criteria by Thursday,” he said.
A yellow heat health alert will also be in place during the same period for Yorkshire and the Humber, the West Midlands and the South West. The Met Office said conditions elsewhere would become more changeable, with cooler and less settled weather arriving earlier from the north and west. Northern areas could see heavier showers, with a small risk of isolated thunderstorms during the week.
Health Concerns Linked to Hot Weather and Dry Conditions
The UKHSA has warned that the amber alert period could bring a rise in heat-related deaths, particularly among people aged 65 and over. Hospitals and care homes may also experience internal temperatures above recommended levels, while water-related incidents could increase due to risks linked to swimming during hot weather.
According to the UKHSA, around 550 people are estimated to have died from heat-related causes in England and Wales during the hot weather in May 2026. The agency also highlighted the impact of the extreme heat seen in 2022, when temperatures exceeded 40C in parts of Britain for the first time on record and were linked to 2,985 excess deaths.
The incoming heat arrives after a period of unusually dry weather in parts of England and Wales. Wales has officially entered drought status after receiving less than two per cent of its expected rainfall for July so far, putting the month on track to become the driest July recorded there in almost 190 years.
According to the Met Office, parts of southern, central and eastern England are currently experiencing “prolonged dry weather”, which is the final stage before drought is declared.
The current forecast points to a short period of high temperatures followed by a return to more unsettled conditions across parts of the country.
