Hot days during Olympics linked to climate change

Climate change-influenced heat is forecasted to impact at least 20 million city residents, tourists, and athletes competing in several iconic events during the final days of the Paris Olympics. Temperatures are expected to peak on Sunday at 35°C. The Climate Shift Index shows that forecasted temperatures will be made up to three times as likely by climate change.  Temperatures in Paris will be 9°C above the average August temperatures.

What events will be impacted?

Climate change-influenced heat is expected to impact the men's and women’s marathons, marathon swimming, cycling, hockey, football, beach volleyball, and canoeing. 

Since Paris last hosted the Olympics 100 years ago, the city has warmed 3.1°C during the Olympics period, according to Climate Central’s Rings of Fire report.

Find a complete list of events impacted by heat here.

How unusual is the forecasted heat?

• Excessive heat is forecasted for the final weekend of the Olympics, with temperatures in Paris expected to reach 28°C on Friday and 30°C on Saturday.

• By Sunday, the peak of this heat is expected as highs reach 35°C, an expected 9°C above average for August. Added humidity could make it feel as hot as 38°C in the shade.

• In other cities that are hosting games as part of this Olympics, including Lyon, Marseille, and Nice, high temperatures during the weekend will be at least four times more likely because of climate change. Temperatures are expected to reach 31°C to 33°C on Sunday. In Bordeaux, the forecast high is expected to reach 42°C. 

• The center of a high-pressure system is forecast to position itself over Western Europe, resulting in temperatures well above average through the weekend.

• Exceptionally warm air from the Iberian Peninsula will move north into west and central France, on the western edge of this high-pressure center.

• Excessive heat ranging from 38°C to 42°C is forecast across western and southwestern France. In the UK, high temperatures up to 28°C are expected on Sunday, including in London.

How has climate change influenced this heat?

• From August 9-11 in Paris, at least 20 million city residents, athletes, and tourists are expected to experience Climate Shift Index (CSI) levels of 3.

• Daily average temperatures are expected to reach Climate Shift Index (CSI) levels of 5 in cities across France including Bordeaux, Toulouse, Lyon, Annecy, Grenoble, and Nice. The CSI of 5 extends into the UK in Southend, Ipswich, Worthing, Brighton, Portsmouth, and Eastbourne. 

  • A CSI level 5 indicates that human-caused climate change made this excessive heat at least 5 times more likely, signifying an exceptional climate change event. 

• Daily average temperatures are expected to reach Climate Shift Index (CSI) levels of 3 not only in Paris, but several other cities in France including Amiens, and Dijon. The CSI of 3 extends into the UK in London, Reading, Oxford, Norwich, Aberdeen, and Wembley. 

• Over the entire period, at least 52 million people in France (not accounting for Olympics athletes and tourists) and 31 million people in the UK will experience at least one day with CSI level 3.

What do experts say?

Dr. Andrew Pershing, VP of Science at Climate Central, said: 

“The heat impacting athletes and attendees in Paris this weekend is much more likely due to climate change. As the summer months grow hotter, the risks associated with holding the Olympics during this season will also grow as we continue to add carbon pollution to the atmosphere."

This event may continue beyond August 11, 2024. Use the Global Climate Shift Index map to stay updated on heat in your region, and see our FAQs to learn about the CSI in both English and Spanish.