When is the next UK heatwave going to be?

A cold Arctic airmass is set to dominate most of the UK over the next two days, leading to below-average temperatures.

The Met Office confirmed the airmass would cover much of the country until at least Friday and cause temperatures to dip, especially in the north.

The UK can expect a mix of clear spells and showers overnight, with heavy showers possible, the forecaster said.

Thursday will bring sunshine and scattered showers, mainly in the north.

Meanwhile, similar conditions are expected on Friday, with blustery showers in the north and drier weather in the south, where temperatures will gradually rise over the weekend.

It comes as the Met Office dismissed reports of a heatwave next week as Britons try to hold on to hopes of warmer temperatures finally arriving to brighten up their summer.

A number of independent weather forecasting groups had claimed that temperatures could reach as high as 28C next Thursday 13 June, kicking off a heatwave.

However, the Met Office said reports of a heatwave were "not a good representation of the current forecast".

Met Office spokesperson Stephen Dixon told Yahoo News UK: "There’s a signal for high pressure to influence weather from the west and south west later in the weekend and into early next week which could reduce some of the showers in the north, though this would likely only return temperatures to near-average for the time of year."

He said this week will see a mix of sunshine and showers, as well as "a chance of some thundery activity mixed in with this in the north".

Dixon said: "Those further south will generally be drier, but even here temperatures will be somewhat subdued compared to recent days."

At the end of last month, the Met Office dismissed reports there could be seven weeks worth of rain this summer.

While temperatures could reach as high as 23C in London and the South East on Tuesday, this will drop to the late teens for much of the country as the week progresses.

In its long-range forecast from 8 to 17 June, the Met Office said there is a "small chance of a more widely settled spell developing for a time next week".

• Read more: UK braced for first 31C heatwave of year as weather maps burn bright red(Birmingham Live)

What is a heatwave?

The Met Office says a heatwave is "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".

It said the UK heatwave threshold is met when a location records a period of "at least three consecutive days" with daily maximum temperatures meeting or exceeding the heatwave temperature threshold.

The threshold differs according to country or county, from 25C in Scotland, Wales, Northern Ireland and the south west of England to 27C on the south east coast of England and reaches 28C in London and other inland areas in the south and south east.

What causes a heatwave?

According to the Met Office, heatwaves are more common when high pressure is allowed to develop over a particular area, typically in summer.

Because high-pressure systems are slow moving, they can persist over an area for an extended period, days or even weeks, bringing hot conditions.

The Met Office said: "They can occur in the UK due to the location of the jet stream, which is usually to the north of the UK in the summer.

"This can allow high pressure to develop over the UK resulting in persistent dry and settled weather."

The Met Office said climate change is making heatwaves more likely, with heatwaves 30 times more likely to occur now than they were before the Industrial Revolution because of the higher concentration of carbon dioxide in the atmosphere.

Is climate change making heatwaves worse?

Many experts have said climate change has pushed up sweltering summer temperatures.

Dr Friederike Otto, a senior lecturer at the Grantham Institute for Climate Change at Imperial College London, said in July 2022 that the soaring temperatures facing the UK would not have been as high without global warming.

“Every heatwave we are experiencing now has been made more frequent, longer and hotter because of climate change,” she said. “Of course, every extreme weather event has also an element of just the chaotic natural variability of the weather system.

“There would have been high temperatures without climate change, but they would not have been as high as what we will see – no matter what exactly we will see, we know for sure it would have been cooler without climate change.”

Heatwaves are made more intense and frequent mainly because overall temperatures are higher due to global warming, and so, when weather systems such as summer high pressure occur, the heat they bring is amplified.

Here's what the upcoming weather will be like for each region of the UK, according to the Met Office.

London and the South East

• Tuesday and Wednesday

A mostly cloudy start with the odd shower possible. Warm. Becoming windy with outbreaks of rain, mostly light, spreading erratically southeast through the afternoon. Becoming drier from the northwest during the evening.. Maximum temperature 23°C.

Sunny spells on Wednesday but the chance of isolated and mainly light showers. Winds freshening through the afternoon, particularly on the coast. Maximum temperature 19°C.

• Thursday to Saturday

Largely dry with sunny spells but the chance of a shower on most days. Showers perhaps more likely on Thursday. Some rather cool temperatures, especially at night. Breezy by day.

South West

• Tuesday and Wednesday

A rather cloudy start and a little damp in places, otherwise, largely dry and bright at first. A band of cloud and patchy rain will arrive into the afternoon. Turning clearer, cooler and a little breezier into the evening. Maximum temperature 18°C.

A rather cool start on Wednesday, then a dry day with sunny spells for all. Winds easing a little, but feeling a little cooler than recent days. Maximum temperature 15°C.

• Thursday to Saturday

Dry with plenty of sunny spells on Thursday. Perhaps a band of rain sweeping south on Friday. Rather cloudy but mostly dry Saturday. Temperatures near normal, with some chilly nights.

Midlands

• Tuesday and Wednesday

A mostly dry start, then a band of cloud and rain, locally heavy, will quickly sweep southeastwards during the afternoon. Becoming drier and brighter during the evening. Turning breezier and feeling cooler and fresher. Maximum temperature 18°C.

A chilly start on Wednesday, then a mostly dry day with plenty of sunny spells. A few showers are possible in the north. A fresh northwest breeze adding to the cooler feel. Maximum temperature 15°C.

• Thursday to Saturday

Sunny spells and scattered showers again on Thursday. Perhaps a band of rain sweeping south Friday. Rather cloudy but mostly dry on Saturday. Temperatures near normal, with some chilly nights.

North East

• Tuesday and Wednesday

Rain moving southeast through the morning, heavy at times with blustery winds, especially over the Pennines. Drier and brighter in the afternoon, with sunny spells briefly following in the evening. Maximum temperature 16°C.

On Wednesday, sunny spells and occasional showers which may be heavy at times. Winds freshening through the day particularly in and around showers. Maximum temperature 14°C.

• Thursday to Saturday

Sunny spells and blustery showers through this period, heavier and more frequent over the western hills. Some rather cool temperatures, especially at night. Best conditions on the east coast.

North West

• Tuesday and Wednesday

A cloudy and damp start as a band of rain, locally heavy, will quickly sweep southeastwards across all parts through the day. Becoming brighter with some scattered showers following by the evening. Breezy and feeling cooler and fresher. Maximum temperature 16°C.

A brisk northwest wind adding to the cooler feel of the day on Wednesday. Sunny spells and scattered, locally heavy, showers, these most frequent in the north. Maximum temperature 13°C.

• Thursday to Saturday

Sunny spells and scattered showers again on Thursday. Perhaps a band of rain sweeping south Friday. Cloudy with some showers on Saturday. Temperatures near normal, with some notably chilly nights.

Scotland

• Tuesday and Wednesday

Cloudy with rain, heavy at times, during the morning. This clears to leave a mix of bright or sunny spells, and scattered blustery showers through the rest of the day. Best of the sunshine in the east. Maximum temperature 16°C.

Wednesday will bring another day of sunshine and scattered showers across the region, best of the dry and sunny spells in the east. Maximum temperature 13°C.

• Thursday to Saturday

Further showers on Thursday, easing off during the evening. A mix of showers and more persistent rain on Friday, again easing later. Drier on Saturday with just the odd shower.

Northern Ireland

• Tuesday and Wednesday

Early rain will clear to the southeast to leave a mix of bright or sunny spells, and scattered showers, mainly in the west. Fresh westerly winds easing. Maximum temperature 15°C.

Wednesday will bring another day of sunshine and scattered showers, blustery at times but easing into the evening. Maximum temperature 14°C.

• Thursday to Saturday

Remaining unsettled over the coming days with scattered showers or longer spells of rain at times, however still some good bright or sunny spells.

Wales

• Tuesday and Wednesday

A mostly dry start, then a band of cloud and rain, locally heavy, will quickly sweep southeastwards during the afternoon. Becoming drier and brighter during the evening. Turning breezier and feeling cooler and fresher. Maximum temperature 15°C.

A chilly start to Wednesday, then a mostly dry day with plenty of sunny spells. A few showers are possible in the north. A fresh northwest breeze adding to the cooler feel. Maximum temperature 13°C.

• Thursday to Saturday

Sunny spells and scattered showers again on Thursday. Perhaps a band of rain sweeping south Friday. Rather cloudy but mostly dry on Saturday. Temperatures near normal, with some chilly nights.