Eco2014 - I live in missouri
You're implying that you think that where you live pertains to "PSI COLD". It doesn't.
It simply means that the tires have been at rest and haven't built-up any heat as the result of running on the road.
"PSI COLD" does go up|down because of the ambient temperature changes, however, it's not related to a particular location/region. *And YA, I know the South is warmer (in general).