Originally Posted by
9easy
Correct.. There is plenty of data in the plane to determine if a landing is safe, and even the most Podunk airport has an ASOS and usually some guy on CTAF. If either pilot thinks it's not safe, divert. Easy enough.
To add to that, it is illegal to land at an airport where the only source of current wx info is awos or asos if it is out of service. The only other option is to have an official wx observer make an observation. ctaf/unicom people are not wx observers generally. Further, if you are on the ground and the asos is reporting "UP" or undefined precipitation, the PIC may make a determination of the precipitation. (for icing / HOT purposes)