ASK THE METEOROLOGIST
“What is dew point?”
Victoria Daugherty, Yreka
The dew point is a direct measure of how much moisture is in our air. It is recorded using the Fahenrehit scale so does reflect a temperature. Another way to think of the dew point, is the temperature at which the air must cool to in order for condensation to occur. When the air temperature cools to the dew point, condensation occurs …or moisture droplets form. This can be in the form of dew, fog, or cloud droplets high in the atmosphere.
The dew point will never be higher than the temperature. When the dew point and temperature are the same, the air is fully saturated. The dew point temperature can tell us how sticky or humid if feels outside. The higher the dew point, the more sticky and uncomfortable it feels. When the dew point is approaching the mid 60’s and 70’s, it begins to feel sticky.
For our area, the dew point can help farmers and orchardists have an idea how low the morning temperature can drop. Because the temperature will never be below the dew point, in the morning hours we look at the dew point temperature to see how long the air temperature could potentially drop. If it’s a cold morning, crops and fruit trees can be damaged by the temperature and these dew points help us understand if critical crop temperatures will be reached.