Brits are set to enjoy a 34C scorcher today as the Met Office predicts sizzling temperatures.
The Met Office said London and potentially some spots in East Anglia are most likely to reach the 34C high, making it the hottest day of the year so far.
Away from the capital and the South East, 27-30C is expected across most of England and Wales.
The UK Health Security Agency (UKHSA) and the Met Office have issued a Level 3 Heat-Health alert for London, the East of England and the South East.
This alert follows the Level 2 alert issued on Tuesday and confirms that the Met Office's threshold temperatures for an alert will be reached in three regions from Friday.
A Level 2 alert remains in place for the East Midlands and South West.
But when will this hot spell end?
Temperatures will fall to the mid 20s in some areas in the south and around London on Saturday, while others may experience thunderstorms.
By Sunday conditions are due to settle into the mid teens, according to the Met Office.
If thermometers do reach 34C on Friday it will be for the fourth time since the 1960s, happening only in 1976, 2017 and 2019 before this year.
The hottest temperature for June was recorded on June 28 1976 when the mercury hit 35.6C in Southampton Mayflower Park.
A spokesman added: “It is very unusual for us to have temperatures of 34C in the month of June.
“It has happened only three times since the 1960s before this year.
“Tomorrow will be the last day of the heatwave for most of the country.
“We may see temperatures of 34C or 35C which is exceptionally high for June.
“After that on Saturday it will be quite a bit cooler, with temperatures in the mid to high 20s in the south and London.
“Sunday there will be some showery rain with average temperatures in the high teens before standard weather for the time of year returns next week when there may even be thunder with temperatures in the mid teens or low 20s.
Met Office Deputy Chief Meteorologist, Jason Kelly, said: “The heat is a result of a mix of home-grown warming due to a high pressure over the southern half of the UK, as well as a south westerly airflow bringing warm air, which has been over the continent through the week, across the country.
“This is the first spell of hot weather this year and it is unusual for temperatures to exceed these values in June.
Some areas may see warm nights with minimum temperatures expected to be in the high teens or even low 20°Cs overnight, especially in urban areas such as London.”
Next week, conditions are expected to return to usual June levels.
Earlier this week a a Level 3 Heat-Health Alert was issued for much of the South East and eastern England, with a Level 2 Alert in place for the South West and East Midlands, with a Level 1 Alert for the West Midlands and northern England.
Agostinho Sousa, Head of Extreme Events and Health Protection at the UK Health Security Agency, added: “Temperatures are forecast to reach 30°C in some parts of the south on Friday and we want everyone to enjoy the hot weather safely when it arrives and be aware of good health advice for coping with warmer conditions.
“During periods of hot weather, it is especially important to keep checking on those who are most vulnerable, such as older people and those with heart or lung conditions. Make sure to look out for signs of heat exhaustion and follow our simple health advice to beat the heat.”
