Weather FIX Found
If you are getting connection errors when trying to download weather, then I have found a fix.
This problem sounded familiar to issues I worked with back on the old HTC Home Plugin with its weather tab.
The issue is with the server we pull weather from which is
http://weather.manila1.htc.com/. This server is basically acting as a proxy between you and accuweather.com where it formats the data to work correctly for the HTC weather app.
One solution is to bypass that server with another one that's been freely provided by an XDA user (N2A) for quite a while now. His "proxy" is
http://weather.not2advanced.com/. His server then acts as the proxy between your phone and accuweather.com.
To get our phones to use his server requires a little work, but not much depending on the method you use.
I used
THIS METHOD which simply requires you to download a zip file and put the folder on your phone somewhere. Run the exe from the phone's file explorer and that's it. If you wanted to add a custom city (one not already in the HTC app), you would need to modify the text file the author includes.
You can also go with
THIS METHOD but its a little more involved.