Maybe the version you had didn't work, but the latest one should be OK. Download from https://addons.mozilla.org/en-US/firefox/addon/1-clickweather/

Thanks for the reply. That is the version that I had. After upgrading to 4.0, when Firefox restarted it warned that several of my add-ons were incompatible and disabled them. You won't believe the arcane procedures I have to go through just to get 1-Click Weather to work intermittently. Several others don't work at all.

You could maybe try a different one. Several here: https://addons.mozilla.org/en-US/firefox/search/?q=weather&cat=all&x=0&y=0

They made need the latest version of Flash to work properly. Yours dates from September 2010. Go to http://get.adobe.com/flashplayer/ to update. The latest version also patched a recently discovered Zero Day exploit. See Adobe releases security update for Flash Player

Also, update Java via Windows Control Panel | Java | Update.

When I upgraded to FF 4.0, a lot of things that needed Flash would not work. When I tried to install the latest v. of Flash, FF 4.0 quit working. I had to reinstall Firefox 4.0 all over again. I am not the only person I know who is having problems. FF 4.0 is so buggy, I am surprised it was released.

There's an update for 1-Click Weather but it needs some tweaking:

https://addons.mozilla.org/en-US/firefox/user/5661757/

I have been using it since I have FF4 and it works just like before.

PS: The link is to the Developer's page.

silverphoenix, Thank you for updating 1-clickweather. I downloaded the 1.1.9.4-fx.xpi file. When I click on it, my new Win 7 installation does not recognize. What am I doing wrong? Thanks!

Drag that XPI file into the Firefox window, or use File > Open File in Firefox.