“Btw, those are GAS laws.”
You need to review Dalton’s law of partial pressures. It states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases.
http://en.wikipedia.org/wiki/Dalton%27s_law
The air in the football of course would normally be a mixture of different gases. Our atmosphere is mostly nitrogen and oxygen with a small percentage of other gasses like CO2 and argon for instance.
Each component gas expands or contracts differently with temperature. So we need to know what the gasses are in the football to determine the pressure at any given temperature.
If the balls,for instance, were filled with mostly CO2, the pressure could indeed change by the pressure difference that was measured in the balls in question. Also any water vapor in the ball would turn to liquid if the temperature was below the dew point.
Since we don’t know at this point what gasses were in the balls in question, and until we do, it’s impossible to say if it could be temperature related.
The volume of the bladder in the ball has nothing to do with it. You can measure the same pressure changes with temperature in a CO2 cylinder or a propane tank.
If you can't verify that phenomenon, I suggest a different climate for a day or two or a change of equipment.
As for gas pressures in a fixed volume (which the leather encased bladder in the ball is, for all practical purposes) temperature is the primary factor in determining pressure within the ball given a fixed amount of air inside.
If you don't believe that, try putting the recommended pressure in your car tires in a 90 degree garage, then park it outside in -30 weather. Then check the pressure after it has cooled off. It isn't the volume in the system, nor water vapor which should not have been present in significant amounts, it is the thermal expansion or contraction of the gasses involved. This isn't a steam engine, it's a football.
Try this law instead: Boyle's Law