I live in Phoenix and during the summer when I check my cold tire pressure it hovers around 35 psi where it should be when the summer morning temps are in the high 60s+ or even the 70s+, then when I'm out on the road in 100+ degree weather later in the day at highway speeds it gets up to around 39, even 40 psi. My questions is about winter conditions, as right now when the temps in the early morning are often in the high 30's or low 40's my cold psi is usually around 31-33 psi, the when out driving when it warms up to high 60's to mid 70's it register's around 35 psi. When it is cold like this should I be inflating the tires such that the morning psi is up closer to the recommended 35 psi, or just assume it is o.k. at the low 30's psi just due to the very cold winter temps in the early a.m.? Thanks in advance for your replies.