PASADENA — A new report from Imperial College London warns that nearly five matches at the 2026 FIFA World Cup could be played in unsafe heat exceeding 28°C (83°F), nearly double the number of such matches during the 1994 tournament in the United States. Human-induced climate change has increased the likelihood of extreme heat in the 16 host cities across the U.S., Mexico, and Canada, according to the researchers.

The report defines unsafe conditions using a wet bulb globe temperature threshold of 28°C, a standard recommended by FIFPRO that accounts for temperature, humidity, and solar radiation. By comparison, FIFA currently only considers postponing matches when this measure exceeds 32°C (90°F). Nearly a quarter of all 2026 World Cup games are projected to exceed 26°C (79°F), with about five expected to surpass the 28°C safety limit.

Sixty current and former professional soccer players issued an open letter urging FIFA to update its heat safety protocols before the tournament. “It can make you feel light-headed, dizzy, experience fatigue, muscle cramps and worse. You can run less and it becomes impossible to play with the same intensity as with more average temperatures,” the players wrote.

Friederike Otto, professor of climate science at Imperial College London and co-author of the report, said the findings demonstrate that climate change is already affecting major sporting events. “That the World Cup Final itself—one of the biggest sporting occasions on the planet—faces a non-insignificant risk of being played in ‘cancellation-level’ heat (28 degrees C or 83 degrees F) should be a wake-up call for FIFA and fans. There is no aspect of society not affected by climate change,” Otto said.

The final match is scheduled for July 19 at MetLife Stadium in New Jersey and carries a 3% chance of reaching the 28°C threshold. In 1994, three matches—including the final at the Rose Bowl in Pasadena, played at 32°C (90°F)—exceeded safe heat levels under today’s standards. The 2026 tournament’s projected increase reflects broader climate trends rather than changes in scheduling or venue selection.