The last bank holiday of May will come to a stormy end as torrential rain looks set to fall across the south east on Tuesday.
Much of the UK will be pleasant on Monday, with some sunny spells, and temperatures in most places will reach the high teens and low 20s.
But the dry weather will not last as a band of rain, wind and thunder from continental Europe will hit Britain overnight on Monday and into Tuesday.
Met Office forecaster Simon Partridge said: "The rain will be locally heavy at times as it comes in, particularly over the south eastern corner of the UK.
"We are currently looking at the possibility of issuing a warning - there will be some pretty heavy bursts in amongst it - with 20-25mm of rain in some places falling in the matter of a couple of hours."
He said the downpours could result in surface water on the roads - potentially causing issues for drivers and commuters.
The system of bad weather will then push its way westwards, affecting mainly southern, central and eastern parts of the UK - with cooler temperatures along the coast.
"The best of the sunshine will actually be in western Scotland and Northern Ireland," added Partridge.
"And by Friday most of the UK will be dry with some decent sunny spells again."