The marine layer explained

When you think of a coastal summer, you typically think of warm temperatures and blue skies… not chilly, gloomy conditions.

And while most of the country experiences its warmest conditions during July and August, that’s not the case here on the Central Coast. And as the famous saying goes… “The coldest winter I ever spent, was the summer in San Francisco,” says Brian Garcia with the National Weather Service.

The marine layer all boils down to California’s climatology. We’ve got cold water during the usually between 55 and 60 degrees, with warm air aloft during the summer time.

That is what is known as a temperature inversion. And it’s in between this layer that we have our low clouds develop. This is due to condensation. But just outside of the marine layer, inland locations get hot. And for people who have spent a lot of time in those spots like Morgan and Alfredo, this weather is welcome. “You don’t sweat, and it’s just beautiful because you are surrounded by the ocean,” says Morgan.

Typically during the summertime we have winds coming out of the west or the northwest, generally,
and this helps clear out skies in the Santa Cruz area towards the middle of the day. But for places on the south side of the bay like Pebble Beach and Asilomar, it’s not unusual to see those patchy low clouds throughout the entire day.

Now once we get past August, our weather pattern starts to change. This brings warmer conditions to our coastal locations.

Garcia says, “Typically that’s when we start hitting our fire season, our peak fire season around here. It’s that September time frame… September, October. Because we have these dry off-shore winds coming out from land out towards the coast.”

You can consider those two months the “real” summertime months on the California coast.