I installed this extension today and it worked with the defaults, but as soon as I decide to change the city to my own, I don't find any way to do that efficiently.
RSS method does not work any more, as noted by the user review above, and the owner's reply to visit the forum is useless, since the forum itself is not searchable for guests and even using the google search on that domain (using site:domain) didn't help that much. If the owner cared enough to make a reply to a user's review, he could have already posted a link to the correct forum post, so that we don't have to loose entire day searching a simple forum.
Also, not being able to find a proper city code means that the module itself is practically useless, unless you want to use default cities.
Also, for some reason, when I finally found a way to get the city codes properly (view source in my browser and analyzing html code from yahoo weather), I realized that Serbian cities' names are not displayed at all with this module. I've checked these codes so far, which don't give any city name at all: 'SRXX0005','SRXX0006','SRXX0008','SRXX0009'
If you check Yahoo Weather page here: http://www.weather.com/weather/right-now/SRXX0005 (and also try with all the other codes I mentioned above) you'll see these are the correct codes.
All-in-all, the module seems like it is working and is fast-loading, but doesn't load the data :) So I don't really know what else to say.