yes it is likely to happen more when it is cold. Think about it when most things get cold they shrink. same thing happens to the air molecules. When this happens tire pressure goes down. It is easy to see a fluxuation of a few PSI with as little of a variance of 10 or more degress.
Enjoying an E89 Z4, E82 128i and Fiat Pop 500 / Missing my E85 Z4 (sold)