On the desktop, it's excessive. But on the iPhone, WeatherBug gives you much more—and much more useful—info than Apple's default app. And in the paid version, hyperlocal, data-driven weather nerdery abounds.
Regular version free, Plus version $1
From The App Developers: WeatherBug is the only source for truly live, local weather – providing users access to the largest network of professional weather stations in the US and thousands of locations around the world.