A heat warning is in place from Friday morning in London as temperatures are set to soar to 31C over the weekend amid thunderstorms.
A yellow alert warning has been issued for the capital from 9am on Friday to 9am on Monday June 12 by the UK Health Security Agency (UKHSA) as well as many other parts of the UK.
The Met Office has also issued a yellow alert for thunderstorms in London on Saturday from 2pm to 9pm.
Temperatures are set to reach a high of 25C in London on Friday and a scorching 31C on Saturday, with a chance of heavy showers or thunderstorms developing later on Saturday.
The showers are forecast to continue on Sunday and Monday, and are expected to be heavy and thundery at times. Temperatures are set to stay warm during the nights as well.
A yellow alert has also been issued in the North East, North West and Yorkshire and Humber.
A yellow alert issued on Wednesday in West Midlands, East Midlands, East of England, South East and the South West was escalated to an amber alert on Thursday.
“Weather impacts are likely to be felt across the whole health service, and at this level we may begin to see some health impacts across the wider population, not just the most vulnerable,” the UKHSA said.
Both yellow and amber alerts remain in place from 9am on Friday 9 June to 9am on Monday 12 June.
Under the new HHA system introduced by UKHSA and the Met Office, a yellow alert means more demand on health care services by vulnerable people is expected, and over 65s, or those with pre-existing health conditions, are at an increased risk.
An amber alert is when increased demand is likely to be felt across the whole health service, with potential for “the whole population” to be at risk, not just vulnerable people.
Britons have been urged to check on vulnerable relatives and avoid the sun during the hottest time of day, between 11am and 3pm.
The warning comes after weeks of prolonged high pressure which has led to the recent sun and high temperatures but as the high pressure moves north, the UK is expected to see higher temperatures as well as thunder, hail and rain hit central and southern England and Wales.
Dr Agostinho Sousa, Head of Extreme Events and Health Protection at the UKHSA, said: “Forecasted temperatures this week will primarily impact those over the age of 65 or those with pre-existing health conditions such as respiratory and cardiovascular diseases.
“If you have friends, family or neighbours who you know are more vulnerable to the effects of hot weather, it is important you check in on them and ensure they are aware of the forecasts and are following the necessary advice.’’
