It's usually just tangled.
I sometimes have to do this chicken dance to fix it - go into settings turn off location everything, back out to home screen (use back key, not home) - then go back in, reset those location settings back to what they were - if your city's already showing, just tap that part of the widget, then update to the bottom left. If your city's stale, pop open google maps to force the location update.
I don't know - but - I still blame accuweather.com - I think that's a big part of our problem, right there - syncing correctly with their server.