A yellow weather warning for thunderstorms has been issued as Britons are urged to brace for hail and lightning.
Southern parts of England and Wales are set to be battered by heavy rain - triggering a risk of flash flooding.
Forecasters say that thunderstorms are most likely to hit south-facing coastal districts while hail and some strong gusts of wind could also strike.
Some areas are expected to see 20-30 mm of rain within two to three hours.
A yellow weather warning for thunderstorms has been issued as Britons are urged to brace for hail and lightningMet Office/ WXCHARTSThe weather warning remains in place from 4pm today until midnight.
The Met Office warns that the heavy showers and thunderstorms may cause some disruption - particularly to travel.
A spokesperson said: "Areas of heavy showers and thunderstorms will move northwards across southern parts of England and Wales later Monday, clearing northwards overnight.
"Some places will see 20-30 mm of rain within 2-3 hours, with a small chance that a few places could receive 40mm.
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"Thunderstorms are most likely for south-facing coastal districts, and hail and some strong gusts of wind could accompany the heaviest showers and thunderstorms."
The unsettled weather comes as the remnants of Hurricane Kirk approach Europe.
While the storm is expected to lose its hurricane status, it still poses a threat of disruptive rain and strong winds for parts of the UK from midweek onwards.
A Met Office spokesperson added: "Consider if your location is at risk of flash flooding. If so, consider preparing a flood plan and an emergency flood kit.
The weather warning remains in place from 4pm today until midnight
Met Office
"Give yourself the best chance of avoiding delays by checking road conditions if driving, or bus and train timetables, amending your travel plans if necessary.
"People cope better with power cuts when they have prepared for them in advance. It’s easy to do; consider gathering torches and batteries, a mobile phone power pack and other essential items.
"If you find yourself outside and hear thunder, protect yourself by finding a safe enclosed shelter (such as a car). Do not shelter under or near trees, or other structures which may be struck by lightning. If you are on an elevated area move to lower ground."