Why does hair take longer to dry after a shower on days with High related humidity?

Hair takes longer to dry on days with high humidity because the air is already saturated with moisture, which slows down the evaporation of water from the hair. When humidity levels are high, the water molecules in the air compete with the moisture in your hair, making it more difficult for the water to evaporate. As a result, the drying process is prolonged, leaving hair damp for a longer period.