By Prof Dr Ian Blackshaw
Another issue facing the FIFA Men’s World Cup, which begins on 11 June and ends on 19 July 2026, is the weather.
Heat, thunderstorms and even poor air quality from wildfires are all features of the summer weather in the United States, Canada and Mexico, where the tournament will be held.
Humidity could also be an issue and, as part of its "commitment to player welfare" FIFA has introduced mandatory three-minute ‘cooling breaks’ in each half of every match of the tournament.
Many of the host cities are subject to high summer temperatures. For example, in parts of the southern United States and northern Mexico, average daytime highs are typically in the low to mid-30s C (mid 90F) but can reach up to 40C (104F) during hotter spells.
When temperature, humidity, wind speeds and the strength of the sunshine combine, players are at great risk of experiencing extreme levels of heat stress on their bodies. With humidity as well, this makes it more difficult for their bodies to cool themselves and this can make things feel hotter still.
There are two heat indexes to consider: one is the 'feels like', which is how the body feels the heat rather than what the temperature is; and the ‘Wet Bulb Globe Temperature’ (WBGT), which assesses the physical heat stress on the body.
In Miami, for example, a typical air temperature of 32C (90F) in the summer would feel like it was 43C (109F), and there is also a WBGT of around 28C (82F), which is regarded as being a threshold when heat stress becomes a significant concern for players.
In a study, which was published in 2025 in the International Journal of Biometeorology, scientists concluded that "14 out of the 16 host locations exceeded WBGT's of 28C (82F) in a summer afternoon.”
Prof Dr Ian Blackshaw may be contacted by e-mail at ‘