Soccer across much of the United States is played in genuine heat, and heat rewrites the pattern of a match. The goals that result look different from the ones cool weather produces.
Pressing is the first thing to be abandoned
A coordinated high press costs enormous energy and pays off only if every player holds position. In heat that discipline breaks down within twenty minutes.
Teams drop into a mid-block instead, conceding possession in areas they would normally contest. The game slows and the number of turnovers near the opposition goal falls.
Fewer high turnovers means fewer of the short, fast goals that come from winning the ball close to the box, which is a large source of scoring in cooler conditions.
The second half opens up because legs give out unevenly
Fatigue does not arrive evenly across a team. Full-backs and wide midfielders cover the most ground and slow first, which opens the flanks before the center.
Attacks then arrive from wide positions against defenders who are a step late, and the resulting chances are crosses and cutbacks rather than through balls.
This is why a match that looked sterile at halftime can produce several goals in the final half-hour without either coach having changed the plan.
Hydration breaks are tactical resets
Official stoppages for drinks are standard in hot conditions, and they hand both coaching staffs an unscheduled chance to talk to the whole team.
Instructions delivered there tend to be defensive, because the trailing team wants to keep chasing and the leading team wants the shape tightened.
The stretch immediately after a break is often the tidiest passage of a hot match, and goals cluster in the minutes before the next one is due.
The ball behaves differently in humid air
Humid air is slightly less dense than dry air at the same temperature, which lets a struck ball carry a little further and swerve a little more.
Goalkeepers notice it on long shots and on crosses that hold up rather than dipping. Handling becomes harder when the ball and the gloves are both wet.
Spilled saves and parries into dangerous areas rise, and with them the share of goals that come from rebounds rather than from the original attempt.
Kickoff time explains more than the standings do
An afternoon start in July and an evening start in the same stadium are effectively different sports, with different physical ceilings and different scoring patterns.
Analysts comparing a team's home and away scoring rates across a summer are often measuring the schedule rather than measuring the team.
Which argues for reading a summer goal record alongside kickoff times and conditions, rather than treating every match in the column as the same kind of test.