The official heatwave will continue into the weekend for much of southern England and Wales, with temperatures likely to peak close to 33°C on Saturday, in what could be the hottest day of the year so far.  

With 30°C already exceeded today (Friday), the UK has now seen five consecutive days of temperatures above 30°C in September for the first time, with that record likely to continue on Saturday and Sunday.  

However, the UK will gradually transition to a cooler air mass in the coming days with an increasing chance of thundery downpours for some, which could lead to further Met Office warnings being issued.  

Met Office Chief Meteorologist Paul Gundersen said: “Although much of the UK will see high temperatures and sunny skies continue on Saturday, in what has a possibility of being the hottest day of the year so far, there’s also the potential for some thunderstorms, which has resulted in a Yellow Warning being issued for much of central England and parts of east Wales. 

“Temperatures will begin to trend downwards from Saturday in the far northwest of Scotland, with a cold front gradually moving south through the weekend, bringing with it the risk of some heavy and thundery downpours on Sunday as well. However, the southeast will hold on to the high temperatures the longest and could still reach 32C on Sunday.”  

Further warnings are likely to be required in the coming days, so it’s important to stay up to date with the latest forecast.  

Chris Wilding, Flood Duty Manager at the Environment Agency, said: “Significant surface water flooding is possible but not expected across parts of England on Saturday afternoon and evening due to isolated intense downpours.

“We urge people not to drive through flood water – it is often deeper than it looks and just 30cm of flowing water is enough to float your car.           

“People should check their flood risk, sign up for free flood warnings and keep up to date with the latest situation at or follow @EnvAgency on Twitter for the latest flood updates.” 

Air Pollution levels through the weekend will also be moderate or high for much of England and Wales.  

As our climate changes due to human influences, hot spells like this are becoming more frequent and severe. By 2070, the chance of exceeding 30°C for two days or more throughout the year increases. Projections show that over southern parts of the UK exceeding 30°C for two days or more becomes sixteen times more frequent than it is today.   

Chance of tropical nights 

In addition to high daytime temperatures, it will remain uncomfortably warm overnight, especially in the south, with a chance of tropical nights for some, which is when overnight temperatures remain in excess of 20°C.    

The highest UK overnight minimum temperature for September on record is 21.7°C, and this record could be threatened in the coming nights. The Met Office previously completed an attribution study examining the influence of human induced climate change on tropical nights in the UK, which is explored in this newly-published blog.  

Heat Health Alert  

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

The Met Office has not issued an Extreme Heat Warning, which covers the UK and aligns with the wider national severe weather warning service and looks at more widespread potential impacts for the public.    

Help to protect the vulnerable people that you know including older people, those with underlying conditions and those who live alone; they may need support to keep cool and hydrated. For more advice click here.    

Further ahead 

By the early part of next week, a return to westerly weather regime, with a mix of sunshine, showers and some windy conditions is most likely, with temperatures returning towards average for the time of year. 

You can check the latest forecast on our website, by following us on Twitter and Facebook, as well as on our mobile app which is available for iPhone from the App store and for Android from the Google Play store. Keep track of current weather warnings on the weather warning page.