Dew Point (DEW)

FreightWaves Customer SuccessWeather

What is it?

A forecast of dew point values.

Who is interested?

Shippers, carriers (fleet and drivers managers), brokers

What does it tell me?

Dew point is expressed as the average forecast dew point value, in degrees Fahrenheit (°F), in a certain U.S. county for the next 48 hours. This is updated hourly.

Dew point is the temperature to which the air needs to be cooled, at constant pressure, in order to achieve a relative humidity (RH) of 100%. At that point the air cannot hold any more water in gas form (water vapor). If the air were to be cooled even more, water vapor would have to come out of the atmosphere in liquid form, usually as fog or precipitation.

The higher the dew point rises, the greater the amount of moisture in the air. This directly affects how “comfortable” it will feel outside. Many times, relative humidity can be misleading. For example, a temperature of 30° and a dew point of 30° gives you a relative humidity of 100%, but it wouldn’t feel “sticky” outside. A temperature of 80° and a dew point of 60° produces a relative humidity of only 50%, but it would feel much more “sticky” or “muggy” because of the higher dew point.