Summer this year has been fairly disappointing in the way of temperatures this year, especially during the second half of August.

However, forecasts this week suggest that September might succeed where August failed in bringing some warmer weather to Wales.

Parts of the UK could see an “official” heatwave in the coming days, with temperatures hitting almost 30C according to forecasters.

The Met Office said that this should come from Monday to Wednesday this week.

This should exceed the usual average for September, which normally stands at around 18C.

Here’s what you need to know about how it will affect Wales.

What is an ‘official’ heatwave?

A location meets the UK heatwave threshold when it records a period of at least three consecutive days with daily maximum temperature levels which vary across the country.

These include 25C for central England and Wales – where it has been forecast the threshold could be exceeded – and 28C for London and the South East.

What does it mean for Wales?

Wales therefore should be enjoying some glorious weather for the early part of this week, with most places reaching the low 20s at least.

Certain areas, including Cardiff and Newport will even reach a high of 27C, with consistently sunny spells and barely a cloud in sight.

However, after that the rain is likely to come feely again, with it still keeping fairly warm, but with a chance of showers throughout.

What has the Met Office said?

Annie Shuttleworth, a Met Office forecaster said: “We are expecting temperatures to rise at the beginning of the new week.

“Sunday will be a cloudy and wetter day for much of Scotland and Northern Ireland while those further south will see bright and sunny conditions with temperatures in the mid-twenties.

“Despite a cloudy start to Monday, conditions will be clear and bright with hot temperatures for large parts of England and eastern Wales as the result of continental air moving in from the south.

“This air will start to push through the country on Tuesday and Wednesday, dragging temperatures as high as 29C for parts of the south-east while Scotland and Northern Ireland will also move into the mid-twenties.

“It’s going to be very warm for the time of year and could even be rather uncomfortable for people trying to sleep at night, with temperatures remaining at around 18C during the evening.

What is the likelihood of an ‘official’ heatwave for Wales?

Shuttleworth said this meant a “decent chance” of an official heatwave for parts of central England and eastern Wales, where the temperature threshold needed over three days is 25C.

However, she warned of an area of low pressure moving in from the west on Wednesday afternoon, bringing with it grey and wet conditions for much of the UK on Thursday.

Thunderstorms are also expected in the second half of the week to conclude the hot spell.

It comes as bookmaker Coral cut odds on a record hot September in the UK from 2/1 to 4/5.

A spokesman said: “Summer may not be over just yet and with a mini heatwave on its way, the chances of this month ending as a record hot September have increased significantly.”