Check out tomn igoe's stuff. He had essentially the same idea - he uses a clock mechanism to display various information, such as email traffic. This project is detailed in Make: volume 11.
Obviously the way you are gathering the data is different - you can skip the (hard) part where he gets the info from the network, you can use a temperature sensor connected directly to the arduino.
The "how to move the clock hand" stuff though is very relevant.
Here is one link, there is heaps of his stuff out there + in his book "Making Things Talk"
http://blog.makezine.com/archive/2008/12/its_email_time.html
http://tigoe.net/emailclock/mailclock1.shtml