Anyone know how to reset outside temperature sensor? on 2007 Chevrolet Trailblazer

It stuck on 20* when it's 50* outside, any help would be appreciated.This problem started yesterday.Auto Temp control 4.2 L.

Thank You

2 answers
Got owners manual? Is it set to the right scale? ----- Well i checked 20°C = 68°F so that ain it.
Does it change at all? No big deal to some but i like my stuff to work too! It has a sensor prob. behind the grill
that can be changed if needed. Check manual, or try unhooking neg batt. cable for a min. That's all I know.
Never had a problem with one. Might be able to scan test body control module to read data. Compass working?
Post results when fixed.
AGREE WITH WETRY POSS C TEMPS INSTEAD OF F TEMPS