"Wednesday still looks to be the hottest day with temperatures reaching 27 to 30C over south and southeast England. London has a 50% chance of reaching 30C, and a 30% chance of 31C, so easily the hottest day of the year so far. Also feeling quite humid.
"The northern half of the UK not seeing the high temperatures and staying a lot fresher.
Temperatures nearer 19C to 21C in south and east Scotland, and 20C to 22C in northern England. Wales and south west England not as hot either reaching the lower 20s and a higher risk of showers.
However, warmer weather could bring a slew of showers. Leon added: "The heat will bring the risk of thunderstorms and local heavy downpours. We may see some flash floods on Thursday as the weather turns gradually cooler and fresher from the west; 30 to 60mm could fall over parts of central and eastern England through the day.
"The week will end some 10C cooler over southern Britain compared to this Wednesday, and a lot fresher, too.
"The outlook is for cooler weather and showers next weekend and early next week, with afternoon temperatures nearer 17C to 19C."
But it's likely to become warmer again later next week, Leon added, with Wimbledon possibly seeing a few short disruptions for showers early next week, but much of the time set to be dry and pleasant.