I use Weather a lot every day. Since it gained hourly forecasts (not just temps, but also humidity and precipitation) it became a lot more useful to me. The fact that the precipitation radar simply doesn’t work right is really annoying though.
In addition, I also use MerrySky a lot and I appreciate that it’s web-based and open. It’s basically what I turned to ever since Apple shut down the DarkSky website. I have bookmarks to its pages that show weather at home, at work, where I run, etc.
Finally, since fog here in the Bay is a big deal (yes, it’s fog here that determines what you wear and how much of it), I use this simple but super useful website several times a day too.