Some parts of the UK could see a month’s worth of rainfall in a single day, forecasters have warned.
The Met Office has issued four yellow severe weather warnings for rain – and affected areas could see local flooding and disruption to transport.
Wet and windy conditions are set to last well into the week, with cooler-than-average temperatures for this time of year.
Met Office forecaster Simon Partridge said: A number of spots around could see, within a few days really, a month’s worth of rain, so a wet, windy, fairly cool week for most.
The first weather warning lasts until the end of the day, spanning from the Humber right down to the south coast, and from the East Midlands to Portsmouth.
Many places will see 20mm of rainfall, while isolated spots could see between 40mm and 60mm.
The average monthly rainfall for the South East in June is about 50mm.
Weather warnings are in force for the whole of Tuesday up to midday on Thursday for northeastern England down to the Wash and as far west as the West Midlands.
Mr Partridge said: There is the potential some spots could see a month’s worth of rain in one day.
It will be fairly localised with a number of other places seeing nearly half of month’s rain – so a very wet day.
In the South East, the top temperature is expected to be 14C or 15C (57F or 59F) – some 6C or 7C cooler than the average for this time of year.
The band of rain will head slightly north and west before settling.
Northern Ireland and Scotland will enjoy the best of the weather, staying mostly dry with sunny spells.
Areas under the rain band will experience temperatures ranging from 13C to 17C (55.4F to 62.6F).