If you're planning on taking a run, you can...more
This weather site is a bit messy in terms of advertisements flickering everywhere, but it provides you with the goods: accurate weather forecasts, radar, and an hour by hour outline of the forecast. It is this last feature that endears it to me most. If you're planning on taking a run, you can check what time the rain is predicted to happen. If you want to go fly a kite, it lets you know what time the winds will be best. In brief: design is a bit ugly, functionality is nice. Oh yeah, they also show air quality and link to an allergy forecast as well.
so far the best free option to getting the weather. even gives you an hourly breakdown.