The Met Office has issued a yellow weather warning for heavy thunderstorms, with flooding expected in some areas of the UK.
Forecasters believe flooding is "likely" in parts of south-west England later today.
The Met Office warning states: "Scattered heavy showers and thunderstorms will continue to develop on Friday afternoon.
"Although many places will remain dry or see little rainfall some sites could see 20-30 mm in an hour and up to 50 mm in 2 to 3 hours along with lightning."
The yellow weather warning, which covers areas such as Torquay, Exeter, Plymouth and Truo, is in place until 10pm this evening.
The Met Office warns that over the weekend, rain and showers are most likely to batter areas across western parts of the UK, coupled with high winds.
Forecaster Alex Deakin said: “Low pressure will dominate through the weekend and into next week and churning around this low pressure, we're going to see slow moving weather fronts.”
And on Saturday, rain storms will batter Northern Ireland and western Scotland, where there is also a weather warning in place.
There will be some showers further east, with Alex adding: "A few showers over parts of eastern England, they could be quite lively. Some thunderstorms are possible, but they will be hit and miss here, so not to be relied upon if you are desperate for some rain."
This unsettled weather is due to be a mainstay across next week too as summer begins to fade into a distant memory.
Low pressure will sit to the southwest, keeping a feed of warm and moist air initially from the continent, but by mid-week, from the Atlantic.
Deputy Chief, Jason Kelly added: “Whilst we are confident that low pressure will dominate the weather well into next week, the day-to-day forecast is not certain at this stage.
"But more generally, each day there will be a risk of showers or longer spells of rain for many areas of the country.
"It is likely that more prolonged showers will bring a risk of thunderstorms too. And in some areas, most likely in the southwest, rainfall totals will build through the week.”
Temperatures are expected to continue to remain above average, with many areas in the low 20s by day and the mid-teens by night.