Motorola Droid : Disappointed With Paid Weatherbug - Temps Always Too Low

I have the paid Weatherbug app and live in Austin, Texas. The value reported by weatherunderground, weather.com, my car, as well as those drive-by LED billboards, tend to be within a couple of degrees of each other (usually 1-2 at max).

Weatherbug however (and correspondingly the Weatherbug site) tend to report temperatures 4-6 degrees lower. I understand that temperatures can vary across a metropolitan area, but 4-6 degrees?

I realize it's their data collection source rather than the phone app itself, otherwise their website wouldn't agree with the phone, which would be an app problem. I also realize it might be geographically isolated, but it's certainly consistently wrong at both my home and my job (26 miles apart, on opposite ends of town).

It would be nit-picking, except for the fact that it's a paid app, and I already dislike their radar/map. This is one paid app I wish I'd skipped.