Indian Summer is a period of unusual warm, dry weather after the end of a traditional summer and was first recorded in 1778. It was, perhaps, so called--Indian Summer-- by American Indians...or because Indians were the first to describe it to Europeans. Indian Summer is the American version of the British All Hallows Summer.
Weather during Indian Summer in San Francisco (Sept - Nov) is milder and warmer, particularly in daylight and the usual fog and chill at night, except for one or two weeks in October when temps soar into the 90s and 100.
During this time of year and just before autumn and Halloween an array of Film and Street Fairs take place in The City like Fringe Festival, Taste of Greece, Folsom Street Fair (Sept 28) and Castro Street Fair (first Sunday in October). San Francisco Giants and Oakland A's fever take over the Bay Area when both teams make playoffs or play in the annual World Series between the American and National Baseball leagues. Various company picnics, barbecues and outings are prominent during Indian Summer.
In The City by the Bay at One Maritime Plaza on Clay Street, it was perfect Indian Summer day for One Maritime property management's sumptuous annual barbecue in appreciation of the buildings tenants, which was celebrated on West Lawn. Tenants enjoyed mouth-watering ribs, chicken and burgers by Bay Area Back Forty Texas BBQ and live music.