Sound like there's a problem at their end - what weather app are you
using ?

the one that comes with ubuntu. (rt click top panel, select add, and you will
see it)

Well, I've just added it to my panel and it's working fine. Have you
checked the settings? It's possible that it's just 'forgotten' which
weather station it should be listening to.

It would help if you said what weather app you use, on what version of Ubuntu.

I am using Ubuntu 10.04 on a laptop at this moment, and I use the weather option
on the clock. It has worked every day in the past week. Is there any chance the
source of your weather information has shut down? I get the temperature from a
nearby, small, private airport -- which has been sold to a developer who will
build houses there. Someday soon I will need to change my "location."