Parts of the UK will be as hot as southern Spain when the mercury peaks at over 30 Celsius (88 fahrenheit) possibly as early as tomorrow.
The heatwave is expected to last until Saturday and forecasters are saying we may hit record levels again before then.
The highest temperature recorded in the UK so far this year had been 29.1 Celsius (84 fahrenheit) at St James Park, central London, on April 19, and it was at the same spot where the mercury hit 29.4 this afternoon.
May 29 saw Scotland and Northern Ireland enjoy their hottest days of 2018, recording 27.5C (81 fahrenheit) and 25.3C (77 fahrenheit) respectively, whilst Wales’ high of 26.8 was on May 27.
Temperatures today were expected to reach 29C in London but the record-breaking temperatures were not anticipated until tomorrow.
Highs today of between 24C to 27C were predicted across England and Wales while Scotland in the south and south east were to enjoy around 25C to 26C and Northern Ireland 25C.
Although it will be one of the hottest weeks of the year, it will not top last June according to Grahame Madge from the Met Office.
He said: “Last June we had five days in a row above 30C which the hottest spell since 1976. We have got a good run this week and we’ve got a good chance of hitting 30C.”
However Mr Madge did urge caution in the hot weather.
“This might not be the week to lay the patio. Although some will be relishing the hot weather, it will be uncomfortable for others. People with breathing difficulties should stay cool, and everyone needs to stay hydrated.”
The TUC has called on bosses to make sure staff working outdoors are protected from the sun.
TUC general secretary Frances O’Grady said: “We all love to see the sunshine, but working outdoors in sweltering conditions can be unbearable and dangerous.
“Bosses must ensure their staff are protected with regular breaks, lots of fluids, plenty of sunscreen and the right protective clothing.”