Wipe it off, and see if it fogged on the inside. It can fog on the outside, if you take it from the cold to a warm house. But a definate no-no on the inside.

The purpose of the nitrogen purging is when you go from a warm house or car to a wet cold outside. Not vise versa.

I have owned a few, and over a dozen Vari-X, and I have had one Vari-X fog about 8 years ago. Sent it back to Leupold. It can happen. And if you own a scope long enough, it will happen sooner or later. No seal is perfect.