A passing cloud or scent of potsmoke, which is commonly experienced while walking the streets of the city of Berkeley, California.  Often used to poke fun at Berkeley's marijuana-friendly population and attitude.
I was walking down Telegraph avenue with a few friends and we encountered the Berkeley fog while passing by one of the head shops.
by IsaacE June 12, 2006
 Get the berkeley fogmug.
Get the berkeley fogmug.