Weather tracker: heat, humidity and thunderstorms a danger at World Cup

With the 2026 World Cup now under way, all 48 teams face a common opposition: summer weather across North America. Matches will be played in 16 cities, from southern Mexico to Canada, with a range of weather risks possible at each venue.Thunderstorms disrupted play before the tournament had even begun. England’s warm-up against Costa Rica in Orlando was delayed by about an hour after storms brought lightning and heavy rain that waterlogged the pitch. Safety regulations at US venues mean play is suspended when lightning is recorded within roughly 8 miles of a stadium, not resuming until 30 minutes after the last strike.The risk of thunderstorms is greatest across the central, eastern and south-eastern US. Among the host cities, Miami and Houston are the most lightning-prone, although Houston’s stadium has a retractable roof. The greatest risk of severe storms over the coming days, however, lies further north-east: scattered storms capable of strong gusts and isolated large hail are possible across the north-eastern US and south-eastern Canada, placing Friday’s Canada v Bosnia and Herzegovina match in Toronto and Saturday’s Boston and New York fixtures at slight risk.The weather hazards likely to pose the broadest challenge to players and spectators are heat and humidity. Temperatures in Monterrey, Mexico can be high in themselves, while the humidity of the south-eastern US is likely to produce the greatest heat strain, even at lower temperatures. Fifa assesses heat-stress risk using wet bulb globe temperature (WBGT), an index combining temperature, humidity, solar radiation, and wind. Many exercise physiologists regard 28C WBGT as the level at which high-exertion play becomes unsafe; Fifa’s own threshold for considering action is 32C. A 2025 study projected that 14 of the 16 host cities will exceed 28C at least some of the time, though several stadiums have roofs and air-conditioning that can mitigate the heat.Tropical storms may also be a risk during the World Cup. Because the tournament falls in the early part of the Atlantic season, most development is likely over the warm waters of the Gulf of Mexico, the Bay of Campeche, and the western Caribbean, rather than the still-cool open Atlantic, meaning that Mexican venues, Houston and Miami are at the greatest risk. The National Hurricane Center ismonitoring a low-pressure area over the Bay of Campeche, giving it a small chance of tropical cyclone formation before landfall into eastern Mexico at the weekend.Mexico City has additional challenges from its altitude. At about 2,240 metres above sea level, its thinner air means reduced oxygen availability, accelerating fatigue and slowing recovery for the players. The thinner air also offers less resistance, which can alter the flight of the ball.Canada’s venues will probably stay comparatively cool throughout the tournament with the lowest risk of disruptive storms. The uneven distribution of disruptive or health-affecting conditions has raised questions of competitive fairness.