Why does it get so dry in your home during the colder months? Simply, arcticair masses do not contain much moisture. When that air is brought inside andwarmed to room temperature without adding any moisture, the relative humiditycan easily drop below 15 percent.So why is that? To understand the principle, one needs to know that relativehumidity is a function of temperature and moisture. Knowing that warm air has agreater capacity for moisture than cold air, it follows that as the temperaturegoes up, the relative humidity must go down.
The extreme dryness associated with arctic invasions is what causes skin tocrack and lips to chap. It can also have some effects on the respiratorysystem.
Story by AccuWeather.com Senior Meteorologist John Kocet.
