A weather warning for rain has been issued to all of Wiltshire just one week after mass flooding caused chaos in towns.

The yellow rain warning which has been issued by the Met Office is currently in place for Sunday afternoon (September 29) and Monday across most of the South West of England and West Wales.

Forecasters warn that further heavy rain is likely to cause some travel delays and flooding, with "some possible interruption to power supplies and other services possible".

Between 20-30mm of rain could be seen within the warning area over nine to 12 hours on Sunday, and 50-80mm could fall in some localised places on higher ground, the Met Office said.

Becky Mitchell, Met Office meteorologist, has warned that although it is “not a huge amount of rain” heavy rainfall the week before means that “river levels are quite high and grounds are quite saturated”, so more flooding could develop.

The flooding in Calne on Monday, September 23.The flooding in Calne on Monday, September 23. (Image: Trevor Porter) This comes just days after flooding in Wiltshire saw towns like Calne left submerged underwater as residents waded through knee-deep floods, and key commuter roads in towns such as Swindon became impassable.

One underpass in Swindon saw flooding as deep as five feet, while the B3106 near Bradford on Avon remains closed due to flooding one week on.

According to the Met Office, some counties in southern and central England have already had more than 250 per cent of their average September rainfall.

Here's how the weather is looking in Wiltshire with the latest warning.

Wiltshire weather forecast:

Sunday - Heavy rain is set to hit Wiltshire from 5pm on Sunday as the yellow weather warning begins.

At 5pm there will be a 60 per cent chance of rain but this will quickly increase to a 95+ per cent chance from 7pm and continuing into the night.

Temperatures will drop as low as 10 degrees once the sun sets, and winds will reach 38mph.

Monday - Relentless heavy rain will continue throughout Monday morning as the yellow weather warning continues.

This is set to continue until 10am, with dark clouds but a dryer outlook for the rest of the afternoon and evening.

Temperatures will reach highs of 15 degrees and lows of 11, with windspeeds of 40mph.

Tuesday - Tuesday will bring some much needed dry weather, but sunshine is still unlikely.

The weather will be mostly cloudy and cold throughout the day, with highs of 14 degrees and lows of 10.

Windspeeds will drop significantly to 27mph.

Wednesday - The weather on Wednesday will be largely the same as Tuesday but with some short sunny spells in the afternoon and highs of 15 degrees.