UK weather: High temperatures for most as thunderstorms set to lash Devon and Cornwall

Yellow thunderstorm warnings are in force for Wednesday and Thursday

Wednesday will remain hot and dry for most of the UK, but thunderstorms are expected to roll across southwestern England and southern parts of Wales later in the day, bringing an end to the mini September heatwave.

Temperatures could reach 29C on Wednesday across south east England, the Met Office has said, following highs of 30.4C in London and 30.3C in Pershore, Worcestershire on Tuesday.

Tuesday’s highest temperature was recorded in Gogerddan, Dyfed, Wales, at 30.7C. These recordings mark only the seventh time that temperatures have exceeded 30C in September since 1971.

Glasgow could see the mercury reach 28C by late afternoon, which would mark the hottest September day in Scotland for more than 100 years. Edinburgh and Aberdeen are set to see highs of 20C and 21C respectively.

But southwest England and southern wales are bracing for storms, as a yellow thunderstorm warning has been issued for 11am until 9pm.

The Met Office said that an area of showers is expected to move northwest across the region. While most areas are not expected to see significant rainfall, some could see 30-50mm in less than three hours in the late afternoon with lightning also posing a hazard throughout the day.

Met Office meteorologist Claire Nasir said: “Some places will see drier weather, no showers at all, but if you catch one, it could turn quite heavy as well as thundery”.

She added that things would become “a bit more unsettled through the latter part of the working week”.

Wednesday night is expected to be muggy as showers begin to push northward, reaching much of England, Northern Ireland and Wales on Thursday.

A yellow thunderstorm warning has also been issued for Thursday from 10am to 8pm, covering most of Scotland, Wales and Northern Ireland, as well as southwest England, the West Midlands and much of northern England.

“Following overnight rain and showers, more intense showers and thunderstorms are expected to break out fairly widely from late-morning, before easing during the evening,” the warning said.

Similar to Wednesday’s warning, most areas will miss the most intense storms, but the Met Office warned where these storms do occur up to 40mm of rain could fall within two hours with the “potential to generate surface water flooding” particularly in urban areas.

The Met Office warned that this flooding could cause delays and cancellations to train and bus services, difficult driving conditions and road closures. In exceptional circumstances, flooding could lead to some rural communities becoming temporarily cut off by flooded roads.

Following the inclement weather, things look a little drier and brighter moving into the weekend. Clouds and patchy rain are expected across much of the country, with highs in the low 20Cs in London and south east, and mid-to-high teens in Scotland and Wales.