UK weather: Met Office map reveals which parts of the UK will have a heatwave this week

The hottest day of the year so far could be recorded three times over this week - and temperatures may get close to 34C (93.2F).

According to the Met Office, the threshold for a heatwave will probably be met or exceeded across large parts of England and Wales.

Temperatures are expected to peak on Thursday - but it isn't likely they will come close to the 35.6C (96F) recorded in Southampton on the hottest June day ever in 1976.

Most of the UK will enjoy sunny and very warm conditions, but the approaching heatwave has prompted the Met Office to issue a level two heat alert for most of England.

Days are forecast to exceed 30C (86F) quite widely and nights are also likely to be warm, with temperatures of 15C (59F) or above in central, southern and eastern England.

Met Office forecaster Luke Miall explained: "We've got high pressure to the South East of the UK over the next few days which is going to be drawing our air up from the continent.

"Although it's fairly uncommon to get 34C in June at the moment, it doesn't look like we're going to break any of the records."

The Met Office defines a heatwave as "an extended period of hot weather relative to the expected conditions of the area at that time of year, which may be accompanied by high humidity".

The heatwave threshold, which varies depending on location, is met when daily maximum temperatures are met or exceeded for three consecutive days.

Heatwaves most commonly appear in summer, when the jet stream is usually to the north of the UK. This allows for high pressure, as well as largely dry and sunny conditions.

The Met Office and Public Health England issue an annual "heat health watch" throughout England from early June to mid-September.

When warnings are issued, they are sent to health and social care workers so they can take steps to protect people's health.

A yellow alert, which is currently in place, is triggered when the risk of reaching threshold temperatures in at least one region for at least two days climbs to 60%.

As of Tuesday morning, there was an 80% chance of this criteria being met between 9am on Wednesday and 9pm on Friday.

So far this week, England and Wales have seen mostly dry, sunny and very warm conditions, while Ireland, Northern Ireland and Scotland have had cloud and rain.

From Wednesday, the latter areas will also experience dry and warm weather, but it will be less warm than England and Wales, meaning the risk of a heatwave will be lower.

Friday will also be hot, but thunderstorms are expected in many places. There is widespread risk of torrential downpours, rain, hail and frequent lightning and strong winds.

Thicker cloud and more persistent rain will then sweep in from the West.

Those who are not a fan of heatwaves will be relieved to hear that fresher, cooler air is expected from Saturday.