Comment What about barometric pressure? (Score 1) 239
What was the local barometric pressure doing over the course of that same time period? Pressure inside a football is relative - to the pressure of the air outside the football.
If you combine temperature's effect on air pressure, a local increase in barometric pressure, and possibly some effect of the temp/humidity change from locker room to field, who knows what the range of change is. Experiments will certainly be the best way to figure that out.