The heatwave currently hitting many parts of the UK is set to continue for at least another week, forecasters say.
The BBC weather centre said conditions would become more unsettled in northern areas towards the end of July, with the south enjoying warm weather for longer.
On Saturday, the highest temperature in the UK this year, 31.4C (88.5F), was recorded at Heathrow.
There are currently delays at London Waterloo train station because the heat has caused a rail to buckle.
Network Rail, which introduced a speed limit near the station last week due to high trackside temperatures, has closed platforms one to four at Waterloo and said "engineers are on site".