Holy CPU!
I left my MBA running unattended for a few hours and came back to it to find the fan roaring. A check of Activity Monitor revealed that Weathervane was eating up more than 300% of the CPU, which needless to say, seemed a bit excessive. I am no longer running the app but I will keep my eyes open for a fix, as its small and neat and pretty much what Im looking for in a menubar weather widget.
Dan Wiencek about Weathervane