June Gloom is a southern California term for a weather pattern that results in cloudy, overcast skies with cool temperatures during the late spring and early summer. June Gloom in southern California is caused by the marine layer effect common to the West Coast, and is enhanced by the Catalina eddy local to southern California. May and June together are usually the cloudiest months in coastal Southern California.
A typical June Gloom day consists of marine stratus clouds covering the coast of southern California, extending a varying distance inland depending on the strength of the June Gloom effect each day. The fog and clouds, which are formed by the marine layer, move in at night, usually after midnight, and typically dissipate in the late morning, giving way to clear, sunny skies. During a heavy June Gloom season, the condition may persist into the afternoon, or even all day during an exceptionally strong event. If the air is saturated with moisture, fog also may develop with June Gloom. Early mornings during June Gloom are typically foggy, with frequent light mist and occasional drizzle. Fog and drizzle normally are found near the furthest inland extent of the gloom, where the cloud deck is closest to the ground. The fog recedes and reveals low clouds by mid-to-late morning; by late morning to early afternoon, solar heating usually is sufficient to evaporate the clouds altogether.
Last day of June means the end of June Gloom, right?
Bring on the sun!