April 22, 2024
may gray and june gloom

May Gray and June Gloom in San Diego

When the fog rolls in, you’ve likely heard the terms May Gray and June Gloom before. This phenomenon is especially prevalent in Southern California.

In the following article, find out what is May Gray and June Gloom, what causes it, and how long it typically lasts.

What is May Gray and June Gloom?

May Gray in San Diego and June Gloom are basically the same thing but occurring during different months. In this section learn what May Gray and June Gloom are and what causes them.

May Gray and June Gloom are characterized by heavy thick fogs and overcast skies that sit over the coastline. Also known as a ‘marine layer.’ Generally, this marine layer sticks to the coastline but when it’s thick – it does travel further inland before dissipating.

may gray san diego
A dense May Gray in California

May Gray and June Gloom are caused by differences in ocean water temperatures and air temperatures. When the water temperature is cold, this causes the air temperature just above the ocean surface to be cooler. However, when overall air temperatures are warming up; the cooler air below will collide with the warmer air above.

As a result, the cooler air is trapped from rising and creates the marine layer. While this weather phenomenon is most common in California – the May Gray and June Gloom effect also happens in other locations with similar climates. These include the Peruvian coast, Canary Islands, Moroccan coast, and Namibia in Africa.

When Does May Gray and June Gloom Happen in San Diego?

Obviously, May Gray and June Gloom occur most commonly in May and June. However, the gray weather can occur as early as April or as late as July (No Sky July) or August (Fogust), depending on the year. As explained above, Springtime is when the water is still cold but the air is warming up which leads to this effect happening most commonly in Spring season months.

May Gray and June Gloom effect will also occur during upwelling events when cold water rushes to the ocean surface.

Generally, this marine layer will burn off by mid-day. However, thick May Gray events will last all day long!

may gray california
May Gray beginning to burn off mid day along the coastline

Surfing May Gray San Diego

When these weather events occur, surfers also have to deal with surfing May Gray in San Diego. Especially during ‘dawn patrol,’ those early morning surf sessions – the fog is particularly thick.

As a result, visibility is more difficult. You may only be able to see a few feet in front of you. Consequently, set waves will surprise you when they come through. Generally, surfers should try paddling out to a spot they are familiar with while visibility is low.

Otherwise, stay alert and paddle out with a friend to be safe!

Lastly, don’t be fooled by the gloomy conditions. UV rays are still present while cloudy so don’t forget to lather on your sunscreen and wear proper sun protection.

Conclusion to May Gray & June Gloom

Ultimately, May Gray and June Gloom is an annual event in San Diego as well as other places in the world with similar climates. It causes for cooler beach days and low visibility surf sessions while it sticks around. But know this, surfing San Diego in summer is right around the corner! Fortunately, San Diego is blessed with long, sunny days for the remaining months in the year.

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  • Gavin Bechtold

    Gavin has been living and surfing in San Diego for over a decade. He loves the ocean and is lucky to call San Diego home. Frustrated with mainstream reviews, he set out to create the best source of surf reviews for San Diego beaches. Check the About page for more info!