Weather Station Quality

After watching observations from my Davis Vantage Pro2 and other nearby weather stations (via wunderground.com), I can say with some confidence that the VP2 is one of the better stations out there. Even excluding cases where other stations have produced completely bogus data, the VP2 seems to produce measurements which are more consistent with nearby airport measurements. Most stations on Wunderground seem to produce good temperature measurements, but some of the humidity values are clearly off. Here are observations from two Oregon Scientific WMR series personal weather stations, two Davis Vantage Pro2 personal weather stations and two nearby airports:

Station	Temp (F)	Dew Point (F)	Humidity
KMAFRAMI4	59.2	37.3	44%
KMAWELLE9	58.8	35.8	42%
KMANATIC3	59.1	49.0	68%
KMAWELLE8	56.3	49.9	68%
KBED	59	48	67%
KOWD	64	52	65%

All of the personal weather stations are in the same general area and are certainly not distant enough to explain the differences in humidity. As you might guess, the first two are the Oregon Scientific WMR series stations, the next two are the Davis VP2s and the last two are airports (all in the western suburbs of Boston). The VP2 dew point/humidity measurements match the airport measurements reasonably closely. Not so for the Oregon Scientific WMR series stations which seem to report consistently low dew point/humidity readings.

Note: My station (KMANATIC3) and KMAWELLE9 are extremely close to each other. The other two personal weather stations are the next closest VP2 and Oregon Scientific WMR series stations. Data was collected at appx. 1:30pm 11/20/09.