"Some big thunderstorms will break out across northern France this afternoon, and there’s a chance that these will clip southeast England on Saturday and overnight.into Sunday," Steven Keates, a Met Office meteorologist, told The Telegraph.
"Monday is looking wet especially in light of further thundery showers across France that could come back across southwest England.
"Heavy rain can bring difficult driving conditions so allow a bit of extra time for your journey and take extra care on the roads. If you’re lucky enough to be camping, it may not be the most pleasant weather to be stuck in a tent but it’ll be just shy of anything disruptive."
The Met Office currently has a couple of watching briefs in place, with the possibility that severe national weather warnings may be required on Saturday night or in parts of England on Monday, but no such warnings have been put in place to date.
Further rain is predicted for the south of England, northern Scotland and Northern Ireland on Sunday, while the rest of the country will likely be dry with some bright or sunny spells.
The Met Office said that some homes in Bedfordshire had experienced flooding on Friday, as Surrey Fire and Rescue Service on Friday alerted drivers to "lots of standing water" on the roads.
Motorists should turn their lights on to be seen by other drivers, the DVLA has urged amid dark clouds and thick rain.
The agency has advised those on the roads this weekend to keep at least double the usual separation distance from other vehicles and to reduce their speed.
It comes as more bad weather is expected the day after parts of the South East endured a month's worth of rainfall in 24 hours.
The Met Office has forecast outbreaks of rain to hit the South late on Saturday afternoon into Saturday night, with the Environment Agency issuing 25 flood alerts, where flooding is possible.
These alerts apply to London and surrounding areas, Kent, parts of the Home Counties, the West Midlands and Wiltshire.
It will be largely dry across most of the UK during the day as temperatures are predicted to range from highs of 19C (66.2F) in London and Cardiff to 18C (64.4F) in Belfast and 17C (62.6F) in Edinburgh. Some sporadic showers are also forecast for Scotland.