Extremely annoying late spring to early summer (and sometimes all summer long) weather phenomenon in coastal Southern California that causes relentless, damp, dreary, miserable weather with drizzle and fog for weeks without end at the beaches. It sometimes spreads into the mountains. This shocks tourists who come to 'sunny Southern California' to instead find themselves in Alaska. It spoils beach days a'plenty and for most locals is the most dreaded time of the year. Number 1 cause for Seasonal Affective Disorder in Southern California. A.k.a. May Gray.
Tourist from East Coast: We're going to sunny Southern California to celebrate Memorial Day and the start of summer.
(Tourist arrives in San Diego)
Tourist: What's up with this stupid weather. Where is the sun?
Local: This is our June Gloom. We've just entered into winter in San Diego. You'll be very lucky if you see the sun at all the next month.