If the water application rate is high enough on the trunk of a young tree, it will be protected by the ice formation. Hence, usually the tops of young trees or branches above the iced zone are more severely damaged after a freeze. Humidity - This refers to the amount of water vapor in the air. There are various ways to express humidity, but the most commonly used terms are relative humidity and dew point temperature. Although commonly used, relative humidity is not the best measure of humidity because it depends on the air temperature.
Warm air holds more water vapor than cool air.
It is also the temperature at which air reaches water vapor saturation. A common example of condensation is the water that forms on the outside of a glass of ice water. This happens because the temperature of the glass surface is lower than the dew point temperature of the ambient air in the room. Hence, some of the water vapor in the surrounding air condenses on the outside of the cold glass. When referring to cold protection, dew point is one of the better ways to describe the humidity or amount of water vapor in the air.