The weather is fetched from Aviation Digital Data Service (ADDS) at http://aviationweather.gov
QRouting checks your route and looks for all the weather stations in the vicinity of your route. Not
only your departure, the destination and the alternative, but all the weather stations within the
range selected from your route.
In the top of the previous screen capture, you can see the 4 options of the weather report.
Range: It is the offset from the route to look for weather stations in.
Hours of history. Displays not only the latest metar, but metars in the previous hours.