I was wading through the jungle of crap on weather.com the other day, trying to dredge out a forecast for my friend Jim. He looks over my shoulder and says to me, "You need to go to weather underground. One visit and you'll never look back."
So, I linked over to Weather Underground (wunderground.com) and I was practically blown away with the utter magnificence of this weather website.
You aren't immediately attacked by multiple ad pop-ups. It is a clean, calm interface. As soon as you type in the zip code of the city you want, you are presented with a clear, concise, well-formatted page of all the info you want. I've always had trouble finding humidity on weather.com, but on wunderground.com it was right there in front of me. The 5-day forecast is clear, and they have a super-cool feature where they compare today with yesterday (e.g., Today will be colder than yesterday). And your last 5 city searches are remembered on the left, so you can quickly check the main places you want to know weather forecasts for.
In short, Jim was right. This site is fabulous. Double-thumbs up for weather underground!!!