Is the weather and moon data accurate to my current location or to the lake I have selected?

By default the moon conditions are specific to the lake you have selected.  You will notice a lake called Current Location.  If that one is selected, your data will be for where you are standing.  However, if you are in northern Wisconsin, and you select Cave Run as the lake to look at, the weather and moon information will behave as if you were on Cave Run Lake.  Please note that most of the time, you'll have the lake selected that you are currently fishing on, which will work out perfectly.