How weather may impact the World Cup

The 2026 FIFA World Cup will be the biggest in the tournament's illustrious history, with an expanded 48-team format.

It will also feature the most diverse weather ever.

"We're using a lot of different techniques to try to combat the conditions that we'll face," said Tim Ream, defender and captain of the U.S. men's national soccer team.

The highly anticipated matches, beginning Thursday, will be spread across 16 venues in North America: 11 in the United States, three in Mexico and two in Canada. Throughout the host cities, it can get hot and humid in the summer.

"We have players that play overseas in Europe, for example, Germany, and then you bring them to Florida or California and they're going to experience a heat impact," said Stephanie Dominguez, performance coach and sports scientist.

For only the second time, FIFA will have mandatory breaks at the 30th and 75th minute to give players a chance to cool off. FIFA's controversial water bottle policy for fans, however, has some people questioning how safe the crowds will be in the heat.

Heat isn't the only significant environmental factor; altitude is also going to be a major player, especially in Guadalajara and Mexico City, both over 5,000 feet elevation.

"They'll feel it immediately in their breathing or their oxygen levels," Dominguez said.

Rain and thunderstorms could also potentially cause huge impacts on some host cities. Miami and Guadalajara typically get frequent showers and storms during this time of year, which could risk lightning delays or pitch saturation. For West Coast cities like Seattle and Los Angeles, however, it's the dry season, and they average little to no rain during these summer months.

So, how does geography and climate shape the field of teams?

"Our country is so big, and so many different climates, that it's not the same anywhere," said John Terry, vice president of event operations at the U.S. Soccer Federation. "A heat in Texas is a lot different than a heat in Boston or Seattle, for that matter."

Heat could also hit the two teams very differently, as well. For example, Scotland will play its third Group Stage match in Miami on June 24 against Brazil. Scotland doesn't often get very hot, with average summer high temperatures in the 60s. The average late June day in Miami is hot and humid, with a peak heat index over 100. Terry said regional weather patterns will oftentimes guide scheduling decisions.

"During hurricane season, we know that it could be an issue to play in Florida, in the heat of the summer playing in Texas, in the middle of the day, could be problematic and so ... we will try to mitigate as much risk as possible," he said. "The humidity factor in this country changes things."

Travel does, too.

"One of the factors that goes into games is travel loads and how far we're traveling, and trying to reduce that as much as possible," Terry said.

The initial group stage is regionalized so teams won't have to travel cross-country, at least not unless and until they advance to the next round.

So, how does the weather affect play, pitch and performance?

Organizers and team monitor the forecast weeks ahead of time so they can be prepared for whatever Mother Nature throws their way on match day.

"We will start monitoring weather probably about 10 to 14 days out before an event ... so we have a baseline idea of what we're going to deal with when we go into a market," Terry said. "We typically work with a meteorologist in the market, where we're going to be, which is important because they're going to understand how weather moves in that city."

The weather on match day could simply impact the playing surface, or it could threaten the safety of players and fans, so it's important to monitor it before and during the match.

"Lightning is certainly a major cause of concern, if not the greatest," Terry said. "Wind is also one as well."

When it comes to weather that is safe to play in, Ream's least favorite conditions may surprise you.

"I can handle the rain, but ... when the wind is blowing and gusting and swirling, it's hard to judge a ball, even when it's when it's on the ground," Ream said. "So windy, super heavy winds are my least favorite to play in. "

So, how do teams and players prepare for environmental extremes?

"The trick to it is training at as high of an intensity as you possibly can in those conditions," Ream said. "If we can train at maximal levels ... in the weather that we're going to be playing in ... your body is automatically going to adapt."

Some teams try to get to the site of their next match five to seven days beforehand, so the players' bodies can adjust to the environment, Dominguez said. They make sure players get iron supplements, eat healthy meals and stay hydrated. The weather even affects what players can do during their downtime.

"We always provide sunscreen for our players," Dominguez said. "You'll see a lot of players ... will wear long sleeves to protect their skin. We try to keep our players out of the sunlight as much as possible."

The two cooling breaks during each match will be extremely important, said Dr. Bert Mandelbaum, chief medical officer for U.S. Soccer and the USNMT's team physician. Rest, cooling towels, ice and fluids will help lower the players' core temperatures.

"They can make better decisions," he said. "They perform better. Their cardiovascular system stabilizes. The fluids and electrolytes balance better, and voila, we have greater performance preservation."

After a long, grueling match, "it's all about recovery, recovery, recovery, recovery ... how to rest the brain, how to get enough sleep," Mandelbaum said. "There are a number of tools that we have: relaxation, Normatech, compression sleeves, ice tanks" and more, he said.

Sleep is, of course, also very important. U.S. players aim for about eight hours a night, and the recovery and treatment process helps them to lower their body temperatures and sleep in low temperature environments.

"There are many different ways to think about sleep and how to enhance it to make sure it is optimal for that particular athlete, especially performing at the highest level on the world stage," Mandelbaum said.