I’ll check the venting on the roof, but certainly no heavy snows here in Phoenix, lol. Should be about 70F today!

These toilets, sinks & showers get used on the daily, morning and night. I’ll check the vent(s) on the roof. As far as dry air this time of year, yes, it is dry, but this was happening sometimes in August & September as well, much more humid. Thanks for all the feedback so far!