WEATHER warnings for rain have been issued by the Met Office for Wiltshire, as rainfall could exceed 1.2in (30mm) today.

The yellow 'be aware' warning is valid from 9am today until 9am tomorrow, the Met Office saying: "Outbreaks of rain, heavy at times, will affect some areas on Tuesday, with an increasing risk of heavy, thundery showers breaking out on Tuesday afternoon and evening - these perhaps lasting overnight into Wednesday.

"Please be aware of possible localised surface water flooding where the heaviest rain occurs."

The warning was first issued on Monday but has now been extended to include Wiltshire and other parts of southern England.

The chief forecaster said: "A frontal zone will bring spells of rain to many areas on Tuesday. Whilst some of the rain will be heavy, rainfall amounts now look less likely to lead to flooding.

"However, there is now a greater risk of some heavy, thundery downpours breaking out during Tuesday afternoon and evening. Many places will miss these, but where they do occur there is potential for over 25mm rainfall in a short space of time with an associated risk of surface water flooding, perhaps most likely across southwest England where showers are slower-moving.

"These may last well into the night before slowly clearing away to the west on Wednesday morning."

Local authority areas affected include Swindon, Wiltshire, Bath and North East Somerset, Bournemouth, Bristol, Cornwall, Devon, Dorset, Gloucestershire, North Somerset, Somerset and South Gloucestershire.

The rain follows a weekend during which Britons enjoyed the hottest days of the year.

Thermometers peaked at 27.1C (80F) in London's St James's Park on Sunday, with Wales, Scotland and Northern Ireland all enjoying temperatures around 10C above the average maximum for May of 14.7C (58.5F).

The hot weather prompted a flurry of betting at the bookmakers that 2016 will be the hottest year on record.

Forecasters predict that Wednesday and Thursday should see temperatures a touch above average, before dipping on Friday to be much cooler and mostly around the mid-teens, peaking at a possible 19C (66.2F).

Alex Burkill, from the Met Office, said: "The weekend is looking mostly dry but cooler than the weekend just gone for most, with temperatures around or a little below the average for the time of year.

"But it should still be pretty pleasant in the sunshine."