Brazil vs Japan in Houston is among the most exposed matches. The forecast cited in the report puts the apparent temperature near 44°C, despite the game being played inside an air-conditioned stadium. Conditions may be most difficult outside the venue, where fans will face heat during travel, queues and entry.
The same concern applies to England vs DR Congo in Atlanta. The apparent temperature there could reach 41°C, creating a sharp contrast between the controlled stadium environment and the conditions surrounding it.
For teams, the tactical impact could be clear:
The risk is not limited to the hottest forecast. France vs Sweden in New Jersey is expected to take place at around 30°C, while Portugal vs Croatia in Toronto could see 31°C.
The report also identifies Argentina vs Cape Verde in Miami and Colombia vs Ghana in Kansas City as uncomfortable conditions. Both cities could reach 32°C, with humidity lifting the apparent temperature towards 40°C. The combined heat-and-humidity measure may approach a threshold considered unsafe by FIFPRO.
That matters in knockout football, where extra-time possibilities make energy management more important. A team that controls its physical output could gain an advantage late in the match.
The heat may intensify as the tournament moves towards the weekend. Philadelphia and New Jersey could see temperatures in the high 30s, with apparent temperatures above 40°C, while parts of Ontario and Quebec may run up to 10°C above normal. Tropical nights, with temperatures staying above 20°C, would also limit overnight recovery.
The next storyline will be whether organisers adjust matchday guidance, supporter access and cooling protocols as the knockout schedule advances.