There are so many weather apps out there... As a general rule, I often find that the pretty ones don't have a lot of information, and the ones with more information provided have worse user interfaces.
Wthr Complete (US$1.99) breaks that rule by adding a lot of depth and a beautiful interface. It has all the usual information, but adds things I like such as sunrise/sunset times and moon phases. It also adds 150 U.S. NOAA weather stations to give you audio forecasts and alerts. There are also detailed radar maps with animation, earthquake maps and the maps have layers so you can see a basic map or satellite view.
Perhaps the most unique feature is a database of the last four years of weather information for any location for any particular day. I find that really useful, as people are always wondering what the weather was on this date last year or the year before. No more guesswork on that subject.
The app has notifications of course, for severe weather and flooding. You can add any number of other cities, and when the app launches you can select the city you want.
Weather conditions have nice animations, and there is nerdy stuff like ultraviolet intensity and dew point as well.
All in all, Wthr Complete is a really nice weather app. Although it is universal, it runs only in portrait mode so many iPad users who spend the day in landscape mode will be unhappy. I'm amazed that developers haven't figured this out. I see new apps almost every week that are locked into the portrait orientation. Dumb. In the wild, almost every iPad I see is in a case or on a stand in landscape mode.
Aside from that failing, Wthr Complete is one terrific little app. It requires iOS 7.1 or later, and it's scaled properly for the iPhone 5 and 6 phones.
There are nice weather apps for free, including Apple's and the well-designed Yahoo weather app, but Wthr Complete goes deeper and is just as pretty.