With Windows Phone 8, developers can now update Live Tiles once a minute. While the clock takes advantage of this to update each minute, weather updates are probably not as rapid. And if you're worrying about how your battery will hold up with the constant 60 second updates to the time, don't even break a sweat. HTC had its Hub running as far back as those dark days that historians refer to as the Windows Phone 7 era. If there was no harsh effect on the battery then, don't expect one now.
The Clock Hub for Windows Phone 8.1 flavored handsets is a free download from the Windows Phone Store. Pin it to a Live Tile and not only will you always have the time staring you in the face, you will also know if you need an umbrella when you go out. Of course, you could look out the window, but what fun is that?
source: ClockHub via WPCentral