Rated 5 out of 5 stars

by Siberian Khatru on May 19, 2014 ·

Install version 2.2.4 from this link:
https://static.getforecastfox.com/downloads/forecastfox-latest.xpi

Though unless you've moved it from the add-on bar, it won't appear unless you also install this addon:

https://addons.mozilla.org/en-US/firefox/addon/the-addon-bar