Claim: Players, staff, and fans are at significant risk of humid heat stress due to climate change. 

The 2026 FIFA World Cup is set to kick off on June 11 with Mexico facing South Africa in Mexico City. Beyond the opening match, games will also be held across the other two host nations, Canada and the United States. In total, matches will take place in 16 cities, with the tournament culminating in the final at New York on July 19.

However, concerns are already mounting ahead of the tournament. A recent report by the World Weather Attribution (WWA) warned of a significant risk of dangerous humid heat stress for players, event staff, and fans attending the matches. According to the report, cities in Canada and along the Pacific coast of the US are expected to experience mild conditions.

In contrast, matches scheduled in more southern and inland regions of the US and Mexico could pose far greater heat-related risks due to higher temperatures and humidity levels.

Our Verdict: True

WWA used Wet Bulb Globe Temperature (WBGT) as the key metric. This accounts for temperature, humidity, sunlight, and wind to reflect how difficult it is for the human body to cool itself. High humidity is particularly dangerous because it reduces the effectiveness of sweating, which is, of course, the body’s main way of cooling itself. 

This can quickly lead to heat exhaustion, dehydration, reduced physical performance, and, in severe cases, heatstroke or other serious medical emergencies. The report highlights that, according to FIFPRO, conditions become risky if temperatures cross 26°C WBGT, requiring cooling breaks and extra hydration.

The games can be stopped if the temperature crosses 28°C WBGT. However, FIFA’s rules mandate that a match can be postponed if the temperature triggers 32°C WBGT levels, which the WWA’s report claims is too lenient. What’s even worse is that climate change has caused the tournament period to be about 0.7°C warmer than during the 1994 World Cup in the USA.

And on top of that, the number of games that are expected to hit this dangerous threshold has increased notably, per WWA. They highlight an increase from roughly 21 games at ≥26°C WBGT in 1994 to about 26 games in 2026. This increase in matches is pronounced in open-air stadiums without cooling, making the risk of humid heat stress even more significant. 

The group that is at the most risk is the players because of the intense physical demands of professional football in hot, humid conditions. And this extends to event officials and fans at the games. The report also highlights that the risk doesn’t diminish for games played during the late afternoon or evening.

The report highlights that a one-evening match in Kansas City has a 7% chance of reaching the unsafe 28°C WBGT level. Air-conditioned stadiums offer some protection inside the venues. But the report warns that climate change has already made the 2026 World Cup significantly riskier overall. Out of the 11 stadiums being used for games in the US, only three feature air conditioning (AC). 

Our fact-checking sources:

• World Weather Attribution, May 14, 2026. Climate Change Big Player at FIFA World Cup 2026