Frank, it sounds like just a weather change phenomenon.
Rapid weather change that you mentioned coupled with the difference in venting in the area.
I would imagine your weather is similar to my area and rapid changes in the weather can do some strange things if you are there to see it when it happens.
My main concern, as I understand the situation you describe, would be any long term moisture problem as exhibited by damage to wood or insulation.
If it is just a transient problem, as I suspect, I will bet you could not duplicate the situation if you try.

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Jim Luttrall
Mr. Inspector.net, Inc.
Allen, Texas 75002