The Gay-Lussac law can explain this.
P/T = K
P = the pressure of the gas
T = the temperature of the gas
K = constant.
that means that if the temperature is higher in summer, the pressure should also be higher in order to not change K (it's a constant)
same applies for if it's colder. if you lower the temperature, the pressure of the gas has to become smaller too in order to keep K a constant.
hope this helps you
