May Gray and June Gloom

Sometimes called "natures air conditioner," marine layer fog plays a significant role in keeping coastal communities along the West Coast comfortable in the late spring and early summer.

If you take a look at the West Coast on the WeatherRadar in the late spring or early summer, there's a good chance you'll see dense low-hanging clouds and fog along the coast. This is referred to as the marine layer.

A marine layer is a shallow, cool, moist air mass that forms over the ocean and drifts inland, frequently producing low clouds, fog, and cool temperatures along coastal areas during spring and summer. While it is common to see this phenomenon in late spring and early summer, it can occur at any time of year. However, the terms "June Gloom" and "May Gray" refer to the frequent presence of the marine layer at this time of year.

The marine layer helps keep temperatures mild and supports ecosystems on the Pacific coast. It provides moisture for plants like redwoods and acts like a natural air conditioner. It’s usually thickest at sunrise and often clears up by the afternoon as the sun warms the land.