UK weather: Hottest day of the year expected as heatwave approaches

The hottest day of the year in the UK could be seen in some areas on Tuesday, potentially leading to an official heatwave.

In parts of south-east England, temperatures are expected to reach 32°C (90°F).

The Met Office said some places in England and Wales are likely to meet heatwave criteria later.

But that could be short-lived – with a yellow thunderstorm warning issued by the Met Office across large parts of both countries later in the week.

A yellow heat health alert has been issued for all parts of England – except the North East and North West – by the UK Health Security Agency (UKHSA).

It is the second of four alert levels – below amber and red – and means the heat is “unlikely to impact most people” but could affect the elderly and vulnerable.

The UKHSA warned that the heatwave could lead to a “likely increase in mortality across the population, particularly in the 65+ age group or those with existing health conditions, but the effects could also be seen in younger age groups”.

It also warns that there is likely to be an increase in demand for remote healthcare services and that internal temperatures in hospitals and care homes could become too high for clinical risk assessments to take place.

Many parts of the country will see temperatures four to five degrees above average for this time of July, BBC Weather said.

In an article published on X, the Met Office on Monday showed the differences in weather between parts of the UK, with Charlwood in Surrey basking in 29.6C heat while Sennybridge in Wales shivered in just 4.9C.

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

It is possible that the criteria will be met in some places on Tuesday.

In the London area, this threshold is 28°C. For Scotland, Northern Ireland, Wales and most of the north and west of England, it is 25°C.

If temperatures do not reach 25C anywhere in Scotland on Tuesday, it will be the first July since 2010 that they have not reached that level.

The drier weather is expected to end across much of the country on Thursday, when the Met Office’s yellow warning for heavy rain and thunderstorms 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 cause disruption.

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

The remainder of the month is expected to bring windy conditions in the northwest and drier, brighter weather in the southeast.

A more widely colonized period is expected around mid-August.