What is the dew point, and what is its significance in a forecast?
The dew point is a direct measurement of the moisture in the air, the temperature at which water can readily condense out of the air to form dew. As the moisture increases in the atmosphere so does the dew point. When the dew point and the air temperature are equal, the air is saturated. (This means that the humidity is 100%). The significance to the forecast is that we can tell what the heat index will be, what the potential for showers will be, and in the winter, if we will have frost or freezes.
