Treasure Island, San Francisco
Island Artificial island in San Francisco Bay, former naval base
Built for the 1939 Golden Gate Exposition, Treasure Island sits in San Francisco Bay between the city and Oakland; visitors come for skyline views, weekend markets, film shoots and access to adjacent Yerba Buena Island.
Treasure Island is an artificial island in San Francisco Bay, created in 1936-37 and notable for its role in the 1939-40 Golden Gate International Exposition. It covers roughly 400 acres and sits adjacent to Yerba Buena Island.
Built by landfill in the late 1930s to host the international exposition, the island was later converted to naval and federal uses. A naval station operated there during and after World War II; much of the military presence ended in the late 20th century and the island has been in civilian redevelopment since.
Situated in the central San Francisco Bay, the island sits adjacent to Yerba Buena Island and is connected to the Bay Bridge; it is part of the City and County of San Francisco.
- Size and origin: Covers roughly 400 acres (about 162 hectares) and was reclaimed from the bay for the 1939-40 Golden Gate International Exposition.
- Views and access: Offers unobstructed skyline views of downtown San Francisco and the Bay Bridge; the island is connected to Yerba Buena Island and the Bay Bridge roadway.
How to Get to Treasure Island, San Francisco #
Ferry service runs from San Francisco’s Ferry Building to Treasure Island; take BART to Embarcadero and transfer to the F-Market streetcar or walk. Driving is possible via the Bay Bridge (I-80), following signs to Treasure Island; parking is available but limited during events.
Tips for Visiting Treasure Island, San Francisco #
- Walk the perimeter at low tide to see WWII-era concrete foundations and pebbled beaches that photographers love.
- Take the Treasure Island Ferry from San Francisco Embarcadero; BART to Embarcadero then MUNI F Market & Wharves is the easiest route to the ferry.
- Check the schedule for the Treasure Island Flea or local food events - they are lively and a chance to meet residents.
Best Time to Visit Treasure Island, San Francisco #
Best in spring or fall for clearer skies and milder winds; summer in the Bay can be surprisingly foggy.
Weather & Climate near Treasure Island, San Francisco #
Temperate climate with mild summers (peaking in September) and cool winters (coldest in January). Temperatures range from 7°C to 24°C. Moderate rainfall (818 mm/year) with a pronounced dry season.
January
January is the coolest month with highs of 14°C and lows of 7°C. Significant rainfall (140 mm).
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February
February is cool with highs of 16°C and lows of 8°C. Significant rainfall (137 mm).
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March
March is cool with highs of 17°C and lows of 9°C. The wettest month with heavy rain (156 mm).
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April
April is cool with highs of 19°C and lows of 9°C. Moderate rainfall (75 mm).
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May
May is cool with highs of 21°C and lows of 11°C. Light rainfall.
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June
June is cool with highs of 22°C and lows of 12°C. Almost no rain.
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July
July is mild with highs of 23°C and lows of 13°C. The driest month with just 3 mm.
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August
August is mild with highs of 23°C and lows of 13°C. The driest month with just 3 mm.
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September
September is the warmest month with highs of 24°C and lows of 13°C. Light rainfall.
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October
October is cool with highs of 22°C and lows of 12°C. Moderate rainfall (59 mm).
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November
November is cool with highs of 18°C and lows of 9°C. Regular rainfall (100 mm).
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December
December is cool with highs of 15°C and lows of 7°C. Significant rainfall (106 mm).
