June Gloom is a mainly Southern California term for a weather pattern that results in cloudy, overcast skies with cool temperatures during the late spring and early summer. While it is most common in the month of June, it can occur in surrounding months, giving rise to other colloquialisms, such as “Graypril,” “May Gray,” “No-Sky July,” “Fogust”, and “Summer Bummer”. Low-altitude stratus clouds form over the cool water of the California Current, and spread overnight into the coastal regions of California.[1]
The overcast skies often are accompanied by fog and drizzle, though usually not rain. June Gloom usually clears up between mid-morning and early afternoon, depending on the strength of the marine layer and the distance of the location from the Pacific Ocean, and gives way to sunny skies. May and June together are usually the cloudiest months in coastal California.[2] June Gloom is stronger in years associated with a La Niña, and weaker or nonexistent in years with an El Niño.[citation needed] This weather pattern is relatively rare, and occurs only in a few other parts of the world where climates and conditions are similar. Scientists study the cloud fields that make up June Gloom to increase understanding of cloud behavior at the onset of precipitation.