Squeeky brakes when cold

[FrozenAKJoe]

I've noticed that when I start driving in the morning, my rear brakes squeek very loudly until I've been driving for a bit. I'd expect them to squeek if they were wet, but this happens when they're just cold. Is this normal? They seem to work just fine, just annoying when cold. Should I have them checked out?

[GMC D-Max]

When I had my truck in for service, I complained about brake squeal with only light pedal pressure. When I picked the truck up, the service dept. notes said "couldn't duplicate/confirm complaint". When I left, the brakes squealed all the way out of the lot. Go figure!
It does appear to be more pronounced when cold, I just turn the radio up louder and don't worry about it!