This map displays relative humidity values observed at a given time. Relative humidity is a measure of how much moisture is present in the air relative to how much moisture could be present in the air if the air was fully saturated. The capacity of air to hold moisture is relative to the air temperature and warmer air masses can hold much more moisture than colder ones. Because of this difference, 100% RH values in a cold airmass won’t feel humid while 70% RH values in a hot airmass will feel unbearable.