Tuesday, July 22, 2008

Why is August the most humid month of the year in Hampton Roads?

Did you ever wonder why the humidity levels in August are so high? The reason is that the ocean temperature reaches its peak in August, which is usually around the 80 degree mark off of Virginia Beach. The warmer the temperature of the water is, the more water vapor evaporates from the surface of the water into the atmosphere, thus raising the humidity levels. The warm water temperature in August lessens the cooling effect of a sea breeze or a gradient wind coming from the ocean. In June, a breeze off the still cool ocean can bring much needed relief to coastal areas. However, in August, the cooling effect of a sea breeze lessens for two reasons. 1) Since the water isn't as cool as it was in June, the air temperature will not drop as much 2) Since the water is warmer and the evaporation rate is higher, the dew point will actually be higher right along the coast.

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