Heatwaves in the UK: how to cope with extreme heat

Learn about heatwaves in the UK, how to cope with extended periods of hot weather as well as tips for first aid and other heatwave advice.

Heatwaves are extreme weather events and, because of climate change, they are becoming more common. In 2022 temperatures hit 40 degrees for the first time in the UK. In the coming decades, it is predicted periods of hot weather and heatwaves will be longer and more extreme. 

Extreme heat can be dangerous. It particularly affects elderly people, babies and children, pregnant women, and those with chronic health conditions People who live in urban areas and on the top floors of buildings can be especially vulnerable.

Find out how to prepare for a heatwave in the UK by exploring tips for keeping cool, learning first aid skills, and making sure you are prepared for when temperatures increase. 

Download our hot weather checklist

Check weather warnings from the Met Office

How to keep cool in a heatwave

First aid advice for heatwaves

Safety advice for UK wildfires and drought

Understanding heatwave weather and periods of extreme heat

What is a heatwave and what causes it?

The word “heatwave” is often used to describe a period of extended hot weather however, this isn’t always correct. A heatwave is a meteorological definition and is officially declared when certain thresholds are met. The Met Office defines a heatwave as “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.”

In the UK, a heatwave is declared when the daily temperature of a certain location meets or exceeds the heatwave temperate threshold for at least three days. There are four heatwave thresholds in the UK reflecting the differences in climate. The lowest, covering places like Wales and Scotland, is 25°c, and the highest, covering London and parts of the East Midlands, is 28°c.

Who is most affected by a heatwave?

A heatwave can affect anyone, but some groups are affected more than others. As heatwaves become longer and hotter, it’s important that these groups are prepared for extreme heat.

  • According to the NHS, the people most affected by heatwaves are:
  • older people – especially those over 75 and female
  • those who live on their own people who have illnesses such as heart or lung conditions, diabetes, and kidney disease
  • people who are less able to cool themselves such as young children, the bed-bound, those with drug or alcohol addictions or Alzheimer's disease
  • people who are more exposed to hot temperatures such as those who live in high-rise buildings, the homeless, or those whose jobs are outside

If you fall into one of these groups, or you know someone who does, please make sure you follow the heatwave advice on this page carefully.

When was the last heatwave in the UK?

The last official heatwave in the UK was in the summer of 2022 when there were three heatwaves from 15 to 17 June, 17 to 19 July, and 9 to 15 August. This came at the same time as several heatwaves across Europe and North Africa.

In the UK, the Met Office issued its first-ever red extreme heat weather warning for parts of England on 15 July, and increased the Heatwave Alert was increased to Level 4 meaning there was a threat of illness and death among fit and healthy people – not just high-risk groups.

The highest-ever temperature for the UK was recorded in Coningsby in Lincolnshire on 19 July and was a record-breaking 40.3°C. Records were also set in Scotland and Wales. Many areas of the UK declared drought and there was an increase in wildfires in urban and rural areas.


Is there another heatwave coming in the UK in 2023?

The Met Office can give long-term forecasts, but it’s impossible to predict exactly when a heatwave may occur.

Usually, when a hot weather warning is given, people will only have a few weeks or even days' notice. The UK experiences its warmest temperatures in the summer months of June, July, and August, but it’s not unusual to also have hot weather in May and September as well. However, the Met Office cannot predict when the next UK heatwave will be a long time in advance.

How long does a heatwave last?

A heatwave lasts a minimum of three consecutive days, though it can be much longer. The longest official heatwave in the UK was in 1976 when the heatwave threshold was met for 15 consecutive days. A heatwave can feel much longer because it usually comes within a period of dry and hot weather. 

Are heatwaves becoming more common?

Heatwaves are extreme weather events and because of climate change, they are becoming longer and more intense. Heatwaves and periods of hot weather have increased in the UK in recent years and are only projected to get hotter and longer. By 2050, the UK will be 50 per cent more likely to experience hot summers, while heat-related deaths could triple to around 7,000 per year. You can learn more about the impact of Heatwaves in our report Feeling the Heat.

Europe heatwave 2023

Eastern and southern Europe experienced record-high temperatures during the summer of 2023 as multiple heatwaves hit the continent. Spain, France, Greece, Turkey, Portugal, and Croatia all experienced temperatures above 40 degrees in July, with parts of Italy reaching 48 degrees, setting new European records. Wildfires have also been a problem, with the Greek islands of Corfu, Rhodes, and the Algarve in Portugal particularly affected.

If you are traveling to Europe or other parts of the world, it's important to be aware of the dangers of extreme heat. You can follow our advice on spotting heat stroke symptomsstaying cool during a heatwave, and what to do in the event of a wildfire.

Always check travel advice from the UK government before traveling and make sure you have comprehensive travel insurance to cover any medical emergencies. You may also want to familiarise yourself with how to access medical support in the country you are visiting in case of an emergency.

Heatwaves and climate change