The 2026 World Cup is currently underway across 16 cities in the United States, Mexico, and Canada, where players and fans face various weather-related challenges. While some venues may remain comparatively cool, the uneven distribution of weather hazards has raised questions regarding competitive fairness. Heat and humidity are expected to pose the broadest challenges to the tournament. According to The Guardian, the humidity of the southeastern United States is likely to produce the greatest heat strain, even at lower temperatures, while Monterrey, Mexico, may experience high temperatures on its own. FIFA assesses heat-stress risk using the wet bulb globe temperature (WBGT) index. While many exercise physiologists consider 28C WBGT to be 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 some stadiums feature roofs and air-conditioning to mitigate these conditions. Other weather risks include thunderstorms, tropical storms, and altitude. Thunderstorms have already disrupted play, such as a warm-up match in Orlando that was delayed by approximately one hour due to lightning and heavy rain. The National Weather Service has issued warnings for severe storms, including potential tornadoes and hail, across several states. Also, tropical storms may develop over the Gulf of Mexico and the western Caribbean, posing a risk to Mexican venues, Houston, and Miami. In Mexico City, the altitude of 2,240 meters above sea level presents challenges by reducing oxygen availability and altering the flight of the ball. Separate from the tournament, NBC News reports that an estimated 26 million people across the West, Plains, and Southeast are experiencing extreme heat this weekend, with some areas potentially reaching 108 degrees. These temperatures are roughly 5 to 10 degrees above typical mid-June levels. These shifts may be linked to El Niño, a natural climate pattern that warms surface temperatures in the tropical Pacific and can amplify warming driven by climate change.