Rainfall in July has been at average levels despite storms which have caused flash flooding around the UK.
Met Office meteorologists said the recent deluge was due to the jet stream being further south than usual, meaning there were extended periods of low pressure in which rain is likely.
The jet stream has now moved northwards which will cause settled, hot weather in parts of Britain until the first week of August.
Temperatures will rise from 26C (78.8F) on Thursday to highs of 31C (87.8F) on Sunday and Monday.
Alex Burkill, meteorologist at the Met Office, said: “Until July 13, the UK had had 55% of its average July rainfall so it’s a bit wetter than average, but not significantly so.
“What is quite likely is as we go through next week, there may be an unsettled blip with the risk of some heavy and perhaps even thundery showers.
“But then as we head through the very end of the month and into August we should see more fine, sunny weather around, and it will be drier than average conditions.
“Whilst it won’t be bone dry all the time, I think we’re in for a warmer and more settled spell that will last a few weeks.”
Mr Burkill added that areas seeing temperatures within the Met Office’s definition of a heatwave include parts of south-west England, South Wales, parts of the Midlands and Yorkshire.
Thunderstorms caused flash flooding in London and the South East this week including multiple Underground stations.
The vets service sees a spike in call outs as the weather warms up and has warned that temperatures above 20C (68F) put dogs at risk and say that survival rates for dogs with heat stroke is just 50%.
Heat stroke can turn fatal in a few as 15 minutes and it only takes a 2C temperature change to kick in.
Dave Leicester, head of telehealth at Vets Now, said: “All dogs can overheat if left without water or in hot conditions for too long. So on hotter summer days it’s best to walk your dog in the morning or evening when it’s cooler.”