Stop HTC weather from geolocating

Try turning off your location services by going to settings, location and uncheck use wireless networks. This service is where most of your apps get there location info from that don't require gps like navigation.
 
I think you have to remove the widget from the homescreen and then re-add it. When you do, you get the option to "add city," use current location, or select one of the default cities (I show NYC and London). I think selecting a city turns off the "by location" function.