Bloglines just launched Weather forecasts and now you can add it by city/state or zipcode. To add weather forecast to your feeds click the "Add" link from your My Feeds display, and then select the "Weather" link. Forecasts are available from throughout the world, and like all of Bloglines, this new feature is localized in the 8 different languages that Bloglines supports.

I use the ForecastFox as an extension on Firefox but I also signed that new feed to my Bloglines. The feed shows the weather prevision for the next seven days and can choose if you want to see the metric system or not.