It looks like it’s going to be hot in North America this year. According to the National Weather Service’s Seasonal Temperature Outlook for the United States, temperatures are expected to exceed historical averages across the country in June and July. In this environment, 48 men’s national teams will come together to win the World Cup, which will be held in the United States, Canada, and Mexico.
As the tournament approaches, The Guardian takes a closer look at the weather conditions players are likely to face, how they have changed since the last time the World Cup was held in North America in 1994 (when the US was the only host nation), and where players are most likely to be exposed to stressful levels of heat.
Among the findings: Each game held in Miami is likely to exceed key temperature thresholds, while heat levels at all venues at Mexico City’s Azteca Stadium have increased over the past 30 years. Researchers have warned that many games are unsafe for players and fans. Nevertheless, Fifpro, the global players’ association, has praised FIFA for listening to their concerns and taking steps to ameliorate the risks to players’ health.
High levels of heat and humidity affect a team’s ability to perform on the field. Wet bulb global temperature (WBGT) is a measure that captures this risk. In addition to temperature, WBGT also takes into account three other measurements: humidity, radiant heat (such as direct sunlight), and wind speed. Sporting bodies use WBGT to define the threshold at which elite sports should be played, and published FIFA rules state that if a WBGT reading reaches 32 degrees before a match, cancellation of the match should be considered. But Fifpro says that level should be set at 28°C.
wet bulb explainer
A study published in the journal Temperature earlier this year found that 31 of the 57 matches played at last summer’s Club World Cup had average WGBT temperatures above 28 degrees Celsius. Analyzing performance data from each match, the researchers found that “the higher the WBGT, the shorter the athlete covered at all speeds analyzed, including high speeds.” The study concluded that “environmental heat stress has a significant impact on the physical performance of soccer players,” and its findings highlight “the importance of employing heat mitigation strategies to protect the performance and health of elite soccer players.”
Data compiled by the World Weather Attribution (WWA) organization can be used to build an assessment of which games are likely to be at risk from heat this summer. Their findings suggest that 26 World Cup matches will be played when temperatures are above 26 degrees WBGT, above which FIFPRO insists there should be a cooling break. If we raise that threshold to 28 degrees, the probability drops significantly, with only 5 matches expected to reach that level, but there are still 45 matches that have at most a 20% chance of reaching that level. Going even higher, WWA data suggests there is a 1 in 4 chance that a match will take place at 30 degrees Celsius WBGT. The numbers are even more striking when compared to the 1994 World Cup. The total number of games expected to be over 26 increased by 52%, but at 28 degrees, that number increased by 75%.
Theodore Keeping, a researcher in extreme weather and climate change at Imperial College London and lead researcher on the WWA data, believes it is “likely” that the 28 degree Celsius threshold will be exceeded. He also said WWA’s valuation could be conservative.
“If we have an anomaly that’s above average temperature, it’s going to be conservative,” Keeping said. “If direct sunlight is an additional factor, that can also have an impact.”
“About half of the anthropogenic climate change has occurred since 1994, when the World Cup was last held in North America. As a result, the climate in which the tournament is played today has changed fundamentally in just 32 years,” says Joyce Kimutai, a researcher in extreme weather and climate change at Imperial and WWA. “While organizers have sought to reduce risk by scheduling some games later in the day in high-risk, unrefrigerated locations like Miami and Kansas City, there is a very real risk that games will be played in conditions that are unsafe for players and fans.”
Three of the cities that are perhaps most exposed to dangerous levels of heat, Houston, Dallas, and Atlanta, have air conditioning installed within their stadiums, effectively eliminating risks within the venue, if not outside, that could affect spectators. FIFA announced a series of mitigation measures during the World Cup draw, including kick-off times for matches in hot conditions, which are often set in the evening, and a mandatory three-minute cooling break between each half. FIFA said it has since gone further, adding additional cooling capacity to stadiums and creating a Heat Stroke Mitigation and Management Task Force to standardize responses when thresholds are exceeded. “Cold bags” will be deployed to help treat patients with “exertional heat stroke,” while spectators will be allowed to bring full bottles of water into the stadium, something that was not the case at last year’s Club World Cup.
Miami Stadium will host Club World Cup matches and will most likely be held in dangerous temperatures during the 2026 World Cup. Photo: Carmen Mandert/FIFA/Getty Images
Once again, Miami Stadium stands out as an exception, with none of the seven games scheduled at the venue kicking off after 7:30pm local time. Perhaps unsurprisingly, the two stadiums in use in Canada, Vancouver and Toronto, are among the least dangerous. However, it seems likely that Mexico’s three stadiums will also be spared the worst.
You can also look at the games most likely to break WBGT standards by team to understand which teams are most at risk from the heat. Two of Uruguay’s three matches are in the high-risk category, while Brazil, Cape Verde, Saudi Arabia and Scotland have one each. Meanwhile, the United States has a low risk of heat effects for all three games.
A FIFA spokesperson said: “FIFA is committed to protecting the health and safety of players, referees, fans, volunteers and staff. Climate-related risks are assessed as part of overall tournament planning and managed in close collaboration with host cities, stadium authorities and national authorities.”
“If the forecast indicates rising temperatures (e.g. above a defined threshold), spectators will be allowed to bring one factory-sealed water bottle and venues will activate additional cooling capacity such as shaded areas, misting systems, cooling baths and expanded water supplies.
“Work and rest cycles for staff and volunteers will be adjusted accordingly, and first aid preparedness will be enhanced with clear triage and escalation paths for suspected heatstroke. These measures will be dynamically scaled based on real-time conditions before and after each event.”
A FIFPRO spokesperson said: “Concerns about player performance, as well as player health, and efforts to adjust competition schedule planning and venue selection are clearly visible. Competition organizers have learned their lessons and have adjusted their schedules. This is normal and necessary. The lesson for everyone in the industry is that due to global warming, heat conditions will have a greater impact on tournament and league scheduling in the future.”
