Mine wasn't showing the night before last for some reason either. I don't use GPS/location, I just have it set via zip code but it's always worked.
I had to go into Accuweather's site and click on 'current conditions' before it would show again. My settings had not changed and were still showing, it just wasn't pulling the info to the dock screen.
When I put it in there last night all was well, pulled up the weather right away.