My recent experience:
In April, in preparation for a 1,500 mile round trip over 4 travel days I aired all 4 tires on my '11 Keystone Outback 250RS to what the label says...65 lbs., rechecked the morning before we left with gauge and the gauge on the air compressor. Temps were in the upper 40's.
On the way back from Arkansas 7 days later, driving in lower 90 degree temps on the interstate at 58-62 MPH, my TST507 TPMS alerted me to an "overpressure" on one tire. Stopped and checked, and it was at 75 lbs...right where I had set the overpressure alert on the TST.
From now on I'll take anticipated temperature differences much more into consideration.