[billybek]

If you own the home you have some things to be concerned about.
One is that you need to install an exhaust fan in the washroom where your shower is.
Two is that the drier should be vented to the great outdoors.
Anything that increases the humidity level in the home will decrease comfort. Except in Western Canada where we actually humidify the air in the winter to increase comfort but that is another topic.
I think that what you are experiencing is pretty normal and natural. When the temperature of the air decreases, it's ability to hold moisture diminishes. That air that you have in the lower level actually contains the same weight in moisture (more or less) as the air upstairs but you feel it is more humid as it is closer to holding all the moisture it can (saturation).
I would suggest that if you have central air conditioning or heating to run the fan in intervals during the day to even out the temperature in the home. Some programmable thermostats will have this feature.
If you are fortunate enough to have a modern fan coil or furnace that has a variable speed drive fan, they can operate low and slow at a very small cost energy wise.