Loud Squeaking Noise from rear wheels?

I don’t drive my 2012 Xterra frequently maybe 1x week and for the past 6 weeks there’s been an increasing squeaking noise that starts once the car is moving and lasts for maybe 2-3 minutes. After that for as long as I’m driving no noise. A friend took a quick peek and said the brakes looked ok and possibly it’s just dirt and I need to drive more frequently. I have been and It seems to be getting louder and lasting longer.

Brake rotors can rust if the vehicle sits for a period of time.

This can cause brake noise when the vehicle is first driven.