phillyg wrote:
Tire manufacturers compensate for temp changes. Always set pressure in the AM and don't change it until the next morning. They may fail for some reason but it won't be from failing to compensate for ambient temps.
While that is good general advice, one also needs to be aware of unusual conditions.
Some places in the western US it is easily possible to drive in a single day where you might have a temp. span of 70 degrees or more; high in the mountains down to death valley for instance.
Under extreme conditions like that you should check and correct the pressure more often.