Nearly one in five matches at the 2026 FIFA World Cup were played in heat and humidity levels that a players' union has previously said should trigger delays or postponements, a Guardian analysis has found. An additional 23 matches were played in cities where outdoor conditions reached those thresholds, but stadium air conditioning mitigated the risk indoors.
Heat Stress and Player Safety
The analysis examined all 104 tournament matches, including 102 already played and forecasts for the two remaining games. Using wet bulb globe temperature (WBGT) estimates—which account for humidity, sunlight, and wind—the Guardian found that 20 matches likely had WBGT readings at or above 28°C (82°F), the threshold at which global players' union Fifpro recommends delaying or postponing games. An additional 23 matches were played in cities where outdoor conditions reached that level, but air-conditioned stadiums reduced the risk.
"The climate crisis is hitting the things we all need, like a stable climate, clean air and affordable food, as well as the things we love, like football and other sports," said Simon Stiell, executive secretary of the United Nations climate body, in a statement.
Broader Implications for Football
The findings highlight a growing challenge for football as global temperatures rise. Extreme heat is becoming more frequent and intense, raising questions about the safety of players and fans at major tournaments. "The 2026 FIFA World Cup matches have introduced a true stress test of heat mitigation and preparedness," said Joshua L. DeVincenzo, assistant director at Columbia University's National Center for Disaster Preparedness. "FIFA, spectators, stadium operators, and others were tested firsthand on the disruptions and complications that extreme heat and weather can pose."
FIFA did not respond to a request for comment. Previously, the organization told the Guardian it stations meteorologists at match venues and coordinates with host cities, stadium authorities, and national agencies. Players received mandatory hydration breaks and access to water, electrolyte drinks, ice, cold towels, fans, mist, and shade.
Record Heat and Wildfire Smoke
The World Cup coincided with a record-breaking heat wave across much of the United States, with over 125 million Americans under dangerous heat alerts. Sunday's final in New York/New Jersey is expected to have a WBGT estimate of just under 26°C (79°F), with low humidity alleviating high air temperatures. However, wildfire smoke could degrade air quality, prompting New York City Mayor Zohran Mamdani to warn of health impacts.
Fifpro declined to comment on the latest analysis but previously told the Guardian: "The lesson for everyone in the industry is that with a warming planet, heat conditions will play a bigger part in tournament and league scheduling decisions in the future."
Hottest Matches
The hottest game in a non-air-conditioned stadium was the France vs. Paraguay round of 16 match on July 4 in Philadelphia. Temperatures at Lincoln Financial Field reportedly reached 38°C (100°F), with WBGT possibly exceeding 33.9°C (93°F). The hottest game overall was Argentina's 2-0 victory over Austria on June 22 in Dallas, Texas, played in one of only three fully air-conditioned stadiums. However, asphalt outside the venue reportedly reached a dangerous 50°C (122°F).
Risks for Spectators
DeVincenzo stressed that precautions must extend beyond players. "Spectator experiences created a secondary risk in the heat; factors such as long walking distances without cover, unshaded areas, sun-exposed seating in the stadium, and long wait times in heat-emitting spaces like parking lots put people at a much higher risk of heat stress and related injuries," he said. He recommended training volunteers to identify heat stress signs and appropriate actions.
Every match in Dallas, Houston, and Miami appears to have been played in conditions breaching the 28°C WBGT threshold. At Miami's non-air-conditioned Hard Rock Stadium, WBGT readings reached approximately 32.5°C (90.5°F) during Norway's match against England, with temperatures of 33°C (91.4°F) and 65% humidity.
Future World Cups
Record-breaking heat and humidity are expected to continue affecting the midwestern and eastern US this week. Looking ahead, the 2030 World Cup in Spain, Portugal, and Morocco will face even more extreme heat due to climate change. The 2034 tournament in Saudi Arabia has been scheduled for the northern hemisphere winter to avoid summer temperatures that regularly exceed 40°C (104°F).
