Wednesday could become the hottest day of the year as parts of the UK are set to bask in the 30-degree heat.
A warm front stretching southeast from East Anglia to Kent means areas within that zone are likely to experience warm “sticky” weather, a Met Office forecaster said.
Regions further north will enjoy much cooler climates, with some showers over Scotland and Northern Ireland.
Mercury is said to be 30 ° C (86 ° F) in London, 22 ° C (71.6 ° F) in Cardiff, 18 ° C (64.4 ° F) in Belfast and 17 ° C (62.6 ° F) in Edinburgh F) reach.
Monday was the hottest day of the year yet, with temperatures in Teddington, Middlesex soaring to 29.7 ° C (85.46 ° F).
Met Office forecaster Simon Partridge said there was a “reasonable chance” that Wednesday’s warmest temperature could beat the record set on Monday.
He said, “It’s going to be pretty tight and there’s a reasonable chance we’ll just skip it.
“There’s a good chance we’ll see temperatures of 30 ° C north of London and a slim chance of 31 ° C (87.8 ° F).
“The heat will be very concentrated in the southeast corner of the UK, with a cold front in the more northerly areas.
“Not only does it get very hot, but it also gets more humid, so it feels really sticky and humid in the early evening.”
Mr Partridge added that most football fans in Wales can look forward to dry, cloudy weather and evening temperatures of around 15 ° C (59 ° F) when the country competes against Turkey at 5pm.
The outlook for fans in East Wales and England could be very different, however, as a yellow weather warning for thunderstorms will apply on Wednesday from 6pm and will last all Thursday until midnight.
The Met Office has also issued yellow warnings for storms that could cause flooding and power outages in the southeast of England for an additional 24 hours on Friday from 9 a.m. onwards.
This warning applies to areas southeast of Hull including Birmingham and areas south except Devon.
Regions further west, including Manchester and most of Wales, could be affected on Thursday but should avoid the second round of storms, according to the Met Office.