BBC Weather Watchers/Juniperbeddy
Blue skies on the beach in Lowestoft, Suffolk
Yellow heat health alerts have been issued for most of England with temperatures set to soar across the country later this week.
Yorkshire and The Humber, East Midlands, West Midlands, East England, the South East, the South West and London are all covered by the alert which comes into force at 12:00 BST on Wednesday and lasts until 18:00 on Sunday.
The alert is the lowest behind amber and red on the UK Health Security Agency's (UKHSA) alerting system, but warns of possible impacts on health and social services.
Temperatures are set to be as high as 26C in London on Tuesday, with an area of high pressure building across the UK likely to bring the first heatwave of 2025 during the week.
All of the affected areas excluding Yorkshire and the Humber have been given a risk score of 10 out of a possible 16, meaning "significant impacts are possible" due to high temperatures.
The UKHSA's website says this includes a possible rise in deaths, particularly among those aged 65 and over or with health conditions, while younger age groups could also be affected.
An increase in demand for health services is likely, it said, and there is a risk the heat could affect the ability of people working in hospitals and care homes to deliver services.
Internal temperatures in hospitals, care homes and independent accommodation could also pose a risk to vulnerable people, it said.
Yorkshire and the Humber's score of seven means that only minor impacts are likely.
According to the Met Office, Tuesday will see cloudy weather with patches of rain in southern Scotland, the east of Northern Ireland, northwest England and northwest Wales.
Sunny spells and showers are expected in northern parts of the UK, and after a locally grey start further south, there will be some very warm sunshine.