Humidity most definitely affects how you feel temperature wise.
The higher the humidity the warmer or hotter you feel.
Think Midwest region, middle of summer, hot and humid. Your body can't dissipate your sweat because the air is saturated. Makes the summer picnic long.
Think Arizona, "Dry heat", if the humidity rises (monsoonal season) folks think the world is coming to an end. Even though the temperature is basically the same sweltering heat it was before the monsoon. Lacking humidity the vast majority can easily deal with the temps when it is hot.
The primary reason for humidification in the cold months is for comfort, that is one of the reasons mechanical contractors always offer them, or should.
Less itchy skin, less dry noses, preservation of good wood etc. are added benefits.