Hottest day of the year so far?

Hot weather will be peaking for many parts of the United Kingdom on Friday.

Widely we will see temperatures of 25 to 30 Celsius.

With the potential for 31C in south-east England, this would make it the hottest day of the year so far.

Cooler weather will spread eastward over the weekend with temperatures more typical for July expected by Sunday.

After a pretty cool start to July where temperatures have been around 2C below average, many of us have welcomed some summer-type warmth.

On Thursday, the temperature reached 28.1C at Heathrow and widely the mercury went above 25C, something we have not seen since the heatwave at the end of June.

Friday will be sunny and very warm - if not hot - in south-eastern areas of England.

Heat health alerts are in force across the Midlands, eastern and southern England until 11am on Saturday.

These alerts are primarily for the health and social care services, warning that heat could impact the elderly and those with underlying health conditions.

The highest temperature recorded so far this year across the UK is 30.5C recorded at Wisley, Surrey on 26 June.

For this to be declared a heatwave the Midlands, much of southern England and East Anglia would need to have three successive days above 27C.

That temperature theshold rises to 28C for London and some of the home counties.

With temperatures starting to fall by the weekend, we are likely to fall just short of this brief hot spell officially being a heatwave in most areas.

With cooler air moving in from the west on Saturday, along with heavy and thundery showers, temperatures will drop for many.

Though across eastern areas of England the heat will remain for one more day with highs expected to reach 26C.

By Sunday the very warm and humid air will have cleared so temperatures across the UK will be more typical of mid-July at 16 to 22C.

Temperatures have reached or exceeded the 30C mark every summer since 1993, so it's not unusual for the weather to get this hot.

The number of days we see over 30C during summer has vastly increased in recent decades compared with the early 20th Century as a result of climate change.