I use Fancy Widget and the temp is way off. I'm not sure if it's stuck necessarily, because it updates the forcast and such, just the temp is wrong. It was saying 78 degrees all day today, when in actuality it was 93 degrees outside. From what I can tell, however, this isn't the widgets problem. From reading around, Fancy Widget uses the Google Weather API to get its weather data, and I pretty much confirmed this by checking the weather on iGoogle, and it's data perfectly matched the data on Fancy Widget.
As the poster above mentioned, the weather on iGoogle is off right now too, I checked it when it was saying 78 on my phone, which seemed off, and the weather on there said 78 too, with everything else matching up as well. However, going to the Weather Channel or even just checking the local news website, gave me temps around 93 degrees, give or take a few degrees depending on where I checked. So, it appears there is something wrong with the Google Weather API, it's not updating the temp or something.