UK weather: Hottest day of year expected as heatwave nears

The Met Office defines a heatwave in the UK, external as “when a location records a period of at least three consecutive days with daily maximum temperatures meeting or exceeding the heatwave temperature threshold.”

It is possible that criteria will be met in a few places on Tuesday.

In the London area that threshold is 28C. For Scotland, Northern Ireland, Wales and most of northern and western England it is 25C.

If nowhere in Scotland reaches 25C on Tuesday, it will be the first July since 2010 that temperatures there have not reached this level.

The drier weather for much of the country is expected to break on Thursday, which is when the yellow warning for heavy rain and thunderstorms issued by the Met Office comes into force.

The thunderstorm warning starts at 12:00 BST on Thursday and ends at 23:59.

Most of southern England, the Midlands, parts of Wales and much of northern England are covered by the alert, which warns of “lightning, hail and gusty winds” that could lead to some disruption.

Warm weather is due to return by Friday – below heatwave criteria but still about 20C in many areas – with some rain showers.

The rest of the month is expected to bring breezy conditions to the north west, and drier and brighter weather to the south east.

A more widely settled period is expected towards the middle of August.