Updated weather information at my fingertips is a wonderful thing. I have weather on my Today screen (HTC Home) and weather on my lock screen (S2U2), but when it comes time to really see what the weather has in store, I go straight to WWM. It's amazing how cleanly you parse everything out and make it clearly available in the different tabs.
Here's my hopefully simple suggestion. As an alternative to always updating when the program runs, could you have an option to only update if the last update was more than x hours ago? You can use the last download time or the last update time. I have the option selected to always update when I run it, but sometimes after I run it and exit, I decide to go back in and look at something else (there's so much good info in there!). In these cases, it's a little frustrating to wait for it to re-download and parse everything. Not that it takes all that long, but it would be awesome if it would just realize it hasn't been long enough to need to.
Thanks, and keep up the great work!