It's good as a demonstration of your skills, but perhaps it should be a sub-page on your own site rather than having its own domain, since the functionality is kind of redundant. Add Celsius temperatures please. Farenheit is sooo 19th century :)

[SanFranciscoFilter] I don't know how much of an issue this is in other places, but Mrs Browl and I were discussing yesterday how useful it would be to have a San Francisco weather map that shows you weather in different parts of the city - it's not unusual for me to look out the window and find chilly fog (in the Sunset) then go to Potrero Hill and find it's a scorcher. Or the other way around.

If you could find multiple SF weather stations and make it into a widget or iPhone app or whatever, there would be a local but decent audience for it, because a single forecast for SF is basically meaningless.