Noticed this the other day and I am wondering if it is normal/common for the dash temp gauge (outside temp) to be off when the car first starts up... After about 5-10 miles, it reads the correct temp. Never noticed it before so now it is driving me crazy (short trip)

 

It’s probably not off. It’s reporting the temp at the sensor, which might be much different, usually warmer in Summer, than ambient until some air starts flowing

 

It's supposed to do that... There is some algorithm that controls when it starts reading "actual" temp.

 

Just curious…how do you know it’s the correct temp? My 2008 seemed consistently report something somewhat higher than what my weather apps says. I attributed that to radiated heat from the car, and I don’t even know where the sensor is because I never looked into it.

 

Mine also reads higher than my various weather apps on my phone. I'm now curious about the sensor's location.

Edit: Found this for the '08 SS:

 

If it's sitting out in the sun the heat collects and it can get 10 to 20 degrees hotter than it actually is and as you drive it moves the hotter than normal air out and you will start seeing the true numbers.

 

except mine is usually parked in the shade so it says lower than the temp showing on the radio, which I am thinking comes from the radio station, and usually is close to the temp from the NWS on my phone. There are more important things to worry about than this on my vehicle... like the odometer keeps going higher each week, and needing an oil change all the time, tires wearing out, and the gas tank seems to go to empty all the time. Maybe I drive too much....

Greybeard999 said it best.. "It's supposed to do that" I'm going to use that for anything I can't explain. Think it will work on the wife??

 

OK, the Ambient Air Temperature Sensor is sitting in a pretty well closed cavity near the radiator and engine. Do you suppose it might pick up some stray heat?
The AlGoreithm used does require a short warm up interval, usually pretty quickly.
2006-2010 it is located on the passenger side frame horn as in Matz post, some 2010 and all 2011 it got moved to the driver side attached to the bumper cover. I serves no function beyond conveniences. The air temp used by the ECM comes from the MAF on LS/LT, I think the SS has a couple of points to measure.

It is just a diode that varies resistance by temperature, the tolerances are not very fine. Could be as much as 10% error.
You can make your own with any diode and a VOM and a calculator. You can turn a NPN transistor into a diode by connecting Collector to Base.

 

Radio stations have no idea where you are, and usually the weather data they get is from the airport nearest them.

 

"Which is weird because nobody lives at the airport" ~ George Carlin