What is the "cold" temperature for tire inflation?

To answer the Ops question, cold tire pressure is first thing in the morning before driving or after the tire has sit for several hours. If it is 30 out then check at 30 and if it is 70 out check at 70 even if both days end at 90. It is a reference check. The manufacturers take into account that during the day and during the drive the tires will heat up.