The Met Office has increased its heat health alert level to Heatwave Action for the south west.
The level 3 amber alert is in place from today (Thursday, August 6) until Tuesday night.
Hot weather and warm nights are expected throughout the region, as warm air spreads north from France.
Met Office chief meteorologist Dan Suri said: “Most of us will see a spell of warm, summery weather later this week, with hot weather developing across southern parts of the UK.
"From Thursday temperatures will be in the low- to mid-20s Celsius for Northern Ireland, Scotland and north Wales and it'll be much warmer across southern and central areas, with temperatures widely reaching 28-29 Celsius."
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The Met Office also warns that these high temperatures could trigger thunderstorms at the start of next week.
A Heatwave Action alert is triggered when the Met Office confirms that threshold temperatures have been reached for one day and the following night, and the forecast for the next day has a greater than 90 per cent confidence level that the day threshold temperature will be met.
This stage requires social and healthcare services to target specific actions at high-risk groups including older people, young children and babies.
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