3 stars is mainly because this used to be a 5-star addon. Now it is just slightly better than the rest. But at least in the new version, the icon couldn't even be moved out of the navigation bar - it remained stuck in 'More Tools'.. So I couldn't even see the basic weather info at a glance.

I like having several days in the addon bar, and being able to hover over one and get more info - ESPECIALLY for the RADAR!
I reverted back to 2.4.8 and turned of automatic updates.. Like more and more addons these days, due to Mozilla's bulls**t. The regular Firefox is barely even usable to me anymore, so I use Cyberfox instead and turn off addon compatibility checking.

I did note that the search was broken like the author said, but fortunately I had all the cities already in. Maybe the author can tell how to manually add them in about:config??

Way to go Mozilla! Continually screwing over all the addon developers again and again and again and again. It's no wonder why so many addons have become abandoned.

Edit after developer reply:
I know it's not you, sorry if I made it sound that way. If it helps, yours [3.4] was the only one I tried that formatted the popup correctly - and looked the nicest and neatest. Hopefully in newer versions you could at least allow the icon/text to be moved elsewhere (including a statusbar, for Firefox forks like Cyberfox).
I can only hope Cyberfox sticks with the older code line, at least as an option. I currently still enjoy having the statusbar, and being able to see multiple days in it, with popup info & radar. I forgot to check if v3.4 allowed popup radar, because that is extraordinarily important to me in a weather addon - as opposed to having to open up a webpage that may take a good while to load.