When extremely hot periods of weather arrive, it can turn our homes into what feels like a giant oven, often making them unbearable to live in.
Bedrooms and living rooms can be the most difficult places to keep cool when temperatures reach over 30 degrees for days at a time.
One thing many of us try and do to keep houses cold in hot weather is open curtains, blinds, and as many windows as possible to let the heat out.
What is a heatwave?
But actually, one of the easiest ways to keep your home cool during a heatwave is to keep your curtains or closed, particularly if the window sits on a south or west-facing wall, according to energy experts.
Additionally, there are specific times of the day when you should keep your windows shut to keep your house cool.
What time and temperature should I shut my windows to stop the heat?
Energy experts at 100Green explained: “When it’s hot outside, it’s best to avoid opening your windows when the outside temperature is higher than the inside temperature.
“In the UK, the average temperature for our homes is around 18°C, so when the weather peaks in the mid-20s in the afternoon, you’ll want to avoid opening your windows until the evening.
How hot will the heatwave be relative to a ‘normal’ July day?
The below charts indicate that many areas could see temperatures 10°C above the seasonal average 🌡️
It also highlights a westward focus on where the peak of the heat will build pic.twitter.com/HGDSUax78f
— Met Office (@metoffice) July 9, 2025
“A good general rule of thumb is to only open your windows first thing in the morning or evening and throughout the night.
“This usually means avoiding having them open between about 11am and 3pm (the hottest part of the day).”
What is the fastest way to cool a hot house?
Other quick ways you can cool your house down in a heatwave, according to British Gas, are:
Eat your meals outside
“Using the oven or hob can create extra warmth so instead of unnecessarily heating up your kitchen, take advantage of warm summer evenings in the garden instead. Fire up the BBQ or throw together a healthy summer salad.”
How you can reduce your energy bills
Use extractor fans cleverly
“Extractors don’t just get rid of smells and steam – during hot weather they can be put to double use. Open your internal doors and leave your bathroom and kitchen fans running for a while to rid your home of some of the excess heat. Don’t forget to shut the doors when you switch the fan off.”
Fix reflective window film
“This is a super effective tool for keeping your house cool in summer by keeping the sun’s rays at bay. It’s not very expensive and widely used in hotter climates, and it can reduce heat and glare by up to 99%.”
Recommended reading:
Has the UK ever hit 40 degrees?
Back in 2022, parts of the UK recorded temperatures of over 40C (104F) for the first time, the BBC reported.
Temperatures hit 40.3C at Coningsby in Lincolnshire, while 33 other locations went past the previous highest temperature of 38.7C, which was set in 2019.
At the time, the extremely hot weather caused a surge in fires, and numerous major incidents were declared by fire services.
Meanwhile, some train services were cancelled due to tracks that overheated or buckled, and overhead cables failed.
