A heatwave is set to hit the UK, sending temperatures soaring into the 30s and sparking a warning for the old, young and those with chronic disease.

In contrast to June so far, which has seen temperatures often near or just below normal, next week could see a real change in the way it feels – with hot days and humid nights, especially across the south.

It looks like heat will start to build across Iberia later this weekend and spread northwards across France early next week as a tropical continental airmass begins to dominate the weather. Temperatures across Iberia and southern France could reach the low 40’s Celsius by midweek with northern France seeing temperatures into the mid to high 30s Celsius.

The UK is likely to be near the boundary between this tropical continental airmass and a tropical maritime airmass over the Atlantic, but we do expect to see temperatures rise across the whole of the UK for the start of July.

Scotland could see highs in the low to mid 20’s (although it may be cloudy here at times), and highs across southern Britain are likely to reach the low 30’s Celsius with a small chance of values in the mid 30’s here.

It’s worth saying that there is some uncertainty about how much of the hot weather from the continent will reach us, and it may only last a couple of days before temperatures drop a little. As is traditional with hot weather in the UK in the summer it may end with thunderstorms.

The Met Office said there was an "80% probability" of heatwave conditions between noon tomorrow and 6am on Thursday in parts of England.

The forecast triggered a 'Level 2' alert with the Met Office warning: "Heatwaves can be dangerous, especially for the very young or very old or those with chronic disease."

A spokesman said: "Temperatures are expected to build on Tuesday and into Wednesday, with the hottest day of the year so far expected on successive days this working week."