Every winter around holiday time, most of us begin to become annoyed by our own dry, cracked and irritated skin. We blame the colder weather this time of year, but the real problem is not outside; it's the low humidity inside that dries out our skin. Whether it is winter or summer, the outside dew point typically ranges from near the air temperature to around 20 degrees lower, leaving the outdoor relative humidity between 40%-100% most of the time.
When the air outside is below freezing or even below zero, the dew point is still 0-20 degrees lower than that. Once our furnaces have raised that air temperature to 65-70 degrees, the indoor relative humidity has dropped to 5%-20%. The indoor temperature is comfortable, but the lack of humidity is not, leaving our skin dry and irritated.