World Cup's knockout rounds collide with a massive heat wave

Fans of Croatia cheer during the FIFA World Cup 2026 match between Croatia and Ghana at Philadelphia Stadium. An NPR analysis of past weather conditions found that the July 4th match in Philadelphia is particularly likely to take place in dangerous conditions. Kevin C. Cox/Getty Images hide caption toggle caption Kevin C. Cox/Getty Images A massive heat wave is sending temperatures into the triple digits in much of the eastern United States, just as the World Cup enters the crucial knockout rounds. Some areas are expected to set new heat records. Climate change means record-breaking heat waves are becoming more frequent. Conditions are particularly dangerous in the Northeast, where temperatures in the 90s combined with very high humidity have prompted the National Weather Service to issue warnings about extreme heat, including in cities hosting World Cup matches. "We are definitely getting into the hottest part," says Daniel Vecellio, a climate scientist who studies extreme heat at the University of Nebraska at Omaha. "This is definitely the week, and coming up this weekend, where some of these systems will be tested." An extreme heat warning is in effect in Philadelphia through the evening of July Fourth, when the city is hosting a match between Paraguay and France. The forecast calls for high temperatures around 100 degrees Fahrenheit, along with high humidity which will make it feel even hotter. The match is scheduled to start at 5 p.m. ET. …