Most of Britain will be bathed in sunshine on Sunday, with the possibility of just a few isolated showers in the south-west.
The mercury is expected to sit around 25C (77F) over central and southern England, according to a spokesman for the Met Office.
“We’re looking at plenty of sunshine across pretty much the whole of the UK, though there’ll be some cloud cover across central parts,” forecaster Simon Partridge said.
Wales may experience some isolated afternoon showers, which are also likely for north-western and western regions of England.
London will start the day with some rain before it clears later.
However, Sunday’s early rain in the capital should not be taken as an indication of widespread wet weather for St Swithin’s Day on Monday.
Folklore says that if it rains on July 15, it will continue for 40 days and 40 nights.
“It’s likely that there’ll be just the odd light shower, possibly along the east coast, particularly in East Anglia,” Mr Partridge said.
“Parts of the coast should see a few showers but nothing like we’d get from a proper band of rain.
“Generally speaking, though, there should plenty of sunshine around on Monday, giving us a dry, sunny start to the week.”
Temperatures will rise to around 27C (80.6F) on Tuesday and Wednesday in the South East.
“It’ll be pretty warm before showers arrive late on Wednesday,” Mr Partridge said.