you can get dew on inside windows on any vehicle under the right conditions, its not that unusual. Just set your selector on full defrost and make sure the a/c is not turned off and they will clear things up and also a/c tends to help remove moisture in the air.
Moisture on the inside can be picked up from any dampness or moisture in things like floor mats with water/mud/snow etc. Also opening a window slightly will help speed up the process. That's why I have the side window visors on my vehicle, that way you can park the vehicle with the window slightly open and not have to worry about getting any rain inside.