A good weather app is essential on an iPhone, because, well, everyone needs to know the weather. After Mail (and probably Messages), weather is next on my list of must-check iPhone apps, followed by online banking and then probably social networks.
The problem is that there are so many of them.
While Yahoo Weather is arguably the best all-around weather app, I also use Dark Sky (for the push notifications) and RadarScope (which has the best radar), and then there's Windscape (which just plain looks cool).
However, my new favorite weather app is Weathertron ($0.99, App Store), which is just the right balance of beauty and functionality. Weathertron was built on the API from Dark Sky and Forecast.io by a couple of self-proclaimed data visualization nerds. It uses 16 different weather sources (most apps use one), then statistically aggregates and weighs the data for better accuracy. But it's the beautiful UI that will win you over.
Weathertron is gorgeous, and organizes the most relevant weather data on two concise today and tomorrow screens that you swipe between.
My favorite is the forecast screen (below), which visualizes the seven-day forecast in a series of minimalist, clean bars that show the high and low temperature, summary icon, and a concise narrative for the week ahead that would make Jony Ive proud.
It's a great first version, but currently lacks radars and multiple location support. But I've got a folder full of weather apps for those.
Here's a demo video:
What's your favorite weather app these days?