I'd like to recommend creating a account so me or other members can assist you, as guest have limitations in replying here and if we need further Information to communicate with you.
Welcome to Android Central! It would also help to know which phone you have. Are you talking about a widget on the homescreen, or is this information that appears in the status bar?
Also make sure that the location information is correct. If it has the wrong location, you're getting that location's temperature. (And make sure that you have it set to what you want - C or F.)