1) http://www.weatherreports.com/ rocks. Simple, crap-ad free, and easy-to-grok at a glance.
2) Also, try typing weather [your-zip-code] into Google — e.g., weather 94112. Nice, eh?
My one complaint? I wish these two offerings would provide more info with one click (hourly forecasts, etc.).
Oh, and here’s one by phone:
3) From any U.S. phone (other than a payphone), dial 1-800-555-8355 (“TELL”) and say “Weather.” Then say a zip code or city name and you’ll get an detailed, often rather extended and informative forecast. TellMe offers lots of other great services, too, that you can glean from their main menu.