How long will this heatwave last? What the Met Office says

The forecasters are expecting temperatures to hit 32C in some places this week, as official heatwave conditions are met.

It is not just during the day where many will be feeling the heat either, as the Met Office forecast overnight temperatures for many in the south could remain in excess of 20C.

The highest overnight minimum temperature for September on record is 21.7°C, and this record could be threatened on Wednesday and Thursday nights in particular.

The Met Office forecasts that the heatwave will peak on Wednesday and Thursday (Image: Ben Birchall/PA Wire)

What is causing the September heatwave?

Met Office Deputy Chief Meteorologist Mark Sidaway said: “High pressure is situated to the southeast of the UK, which is bringing more settled conditions with temperatures on the rise through the first half of this week.

“While the highest temperatures are expected in the south, heatwave conditions are likely across much of England and Wales especially, with parts of Scotland and Northern Ireland also likely to see some unseasonably high temperatures.

“An active tropical cyclone season in the North Atlantic is helping to amplify the pattern across the North Atlantic, and has pushed the jet stream well to the north of the UK, allowing some very warm air to be drawn north.

“It’s a marked contrast to the much of meteorological summer, when the UK was on the northern side of the jet stream with cooler air and more unsettled weather.”

The UK Health Security Agency, which provides alerts specifically for the health and social care sector, has issued a Yellow Heat Health Alert which highlights increased risks to those more vulnerable to heat.

How long will the heatwave last?

The Met Office forecasts that the heatwave will peak on Wednesday and Thursday, with temperatures gradually declining as we head into the weekend.

However, those in the southwest of the country could continue to experience heatwave temperatures past that.

Mark Sidaway continued: “A cold front will begin to influence things from the northwest ahead of the weekend, bringing temperatures down and an increasing chance of rain for those in the west of Scotland and Northern Ireland.

“There’s still a large degree of uncertainty on the exact timing of this front, and there’s a chance that those further south in the UK could keep some higher than average temperatures through much of the weekend, perhaps even into the start of next week, though even this will be a step down from the peak that we’ll see in mid-week.”