Courtesy of WOWSA, Huntington Beach, California.

As you drive down the California coast, you can often hit a marine layer as you near the shoreline.

The marine layer often hovers over the coastal areas and lifts when the sun rises and the temperatures rise.

In the case of coastal California, the offshore marine layer can also contains fog. The fog lingers until the heat of the sun becomes strong enough to evaporate it, often lasting into the afternoon during the May gray, June gloom, No-sky July or Fogust periods.

It is no wonder that California lifeguards often wear jackets during the summer month which seems so out of character. Why?

The California beaches can get quite chilly in the summer with its frequent marine layers descending upon the coastline in the early morning hours until nearly the early afternoon.

The marine layer clouds that impact California are low-altitude stratus clouds that form over the adjacent ocean waters.

The formation of these clouds usually begins when wind over the water surface mixes moist surface air upwards. As this air moves up, it expands and cools. The cooling causes the relative humidity to increase and once the relative humidity reaches 100%, condensation of water vapor into liquid water drops takes place and clouds begin form.

In some beaches, the marine layer lingers for hours as the beach-goers from inland desert areas flock to the beaches and are pleasantly surprised to enjoy a significantly cooler climate.

“Also, it can get windy up in the lifeguard tower too. Even when it’s calm on the sand it’s much cooler and more windy up in the tower,” said former lifeguard Lexie Kelly shown above.

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