The key figure in the report is 28C. Above that mark, the update says, football tends to change:
That matters because modern elite football is built on repeat high-intensity actions. Pressing, counter-pressing and fast transitions all depend on players being able to explode, recover and go again. If heat chips away at that cycle, matches can become more cautious and more fragmented.
The report says 97 of 104 scheduled games are now more likely to be played above that threshold, with nearly half carrying at least a 50% chance of doing so. Even allowing for the need for caution around a single-source claim, the direction of travel is clear enough: heat is becoming a competitive factor, not just a welfare talking point.
The clearest example cited is Uruguay against Spain in Guadalajara on 26 June. The report puts the chance of temperatures rising above 28C at 70%, with climate change said to have increased that risk by 37 percentage points.
That fixture is a useful case study because it pairs technical quality with a likely demand for sustained tempo. If conditions are heavy, possession could become more valuable, recovery runs more difficult and substitutions more decisive. Squad depth may matter as much as star power.
Expect practical adaptation if these concerns grow nearer kickoff:
The next storyline to watch is whether organisers and teams start treating heat like any other competitive variable. Scheduling, training loads and in-game management could become central themes long before the first ball is kicked in 2026.