The most significant threat to the 2026 World Cup is not a rival on the pitch but the air itself. Researchers at the World Weather Attribution initiative have warned that roughly a quarter of the tournament’s 104 matches could be played under temperatures exceeding the safety thresholds recommended for elite athletes. The probability of encountering such extreme heat has nearly doubled since the United States last hosted the tournament in 1994, a reflection of how profoundly climate change has altered the playing field in just three decades. Viewed from Washington, where officials are preparing to co-host the first 48-team edition across Canada, Mexico and the United States, the warning adds a stark environmental dimension to what was already the most logistically complex World Cup in history.

To measure the risk, scientists used the wet-bulb globe temperature index, which accounts not only for ambient heat but for humidity, solar radiation and wind speed — factors that together determine the physiological stress on a human body. The analysis singled out specific fixtures, including Argentina’s group-stage match against Austria in Dallas on 22 June, as particularly dangerous. In Latin America, where the Argentine and Brazilian presses have led coverage, the study landed with particular force. Lionel Scaloni, Argentina’s coach, had already flagged concerns after the draw last December, warning that playing in “places of much heat” would require a benevolent schedule. His instinct now has empirical backing.

Across the Atlantic, analysts in London note that the study comes from Imperial College and the Red Cross Red Crescent Climate Centre, lending it institutional weight. The tournament’s expansion to 48 teams, a FIFA decision driven by commercial ambition, means more matches crammed into the North American summer, with June and July bringing peak heat in cities such as Dallas, Houston and Monterrey. FIFA has authorised mandatory hydration breaks, but the researchers argue that such measures treat symptoms rather than causes. The conditions, they say, will constrain tactics and risk the health of players who are already pushing physiological limits.

The new World Cup format — top two from each group plus the eight best third-placed teams — guarantees 104 matches rather than 64, increasing the likelihood that at least some will fall in the hottest windows. As the countdown to the 11 June kick-off in Canada begins, the climate question becomes inescapable. Will FIFA adjust kick-off times, shift games to cooler northern venues, or simply accept the risk? The study is not a forecast but a probability analysis, and it makes clear that climate change is now a permanent, unignorable player in the game.