Uh, not on this particular GPS model. I am a beta-tester for Garmin (the GPS in the photo will be available in stores this month, and I have had it since July). I already asked about temperature display - this particular model does not have the hardware support needed to display temperature.
Advances in electronics technology have enabled the GPS manufacturers to monitor critical circuit board temperatures without having to put in a special purpose temperature sensor - so, unless they want to have temperature display as a model specific feature, the GPS cannot display it.
Because this model is designed as an automotive unit, there was no compelling reason to have temperature display - it would only display the temperature of the interior of the car, who cares about that?