What Causes San Francisco Fog and Where to View It

It shrouds the city in poetic softness during the summer

San Francisco Fog
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San Francisco, that place where just about everyone (and especially Tony Bennett) famously leaves their heart, is also famous for its fog. Maybe the fog is part of the reason. As Carl Sandberg wrote in his well-known poem "Fog," "The fog comes on little cat feet. It sits looking over harbor and city on silent haunches and then moves on." Sandburg wrote these evocative and memorable words not about San Francisco, but rather about Chicago.

But it describes how the ever-present fog feels in San Francisco to a "T." If you visit in the summertime, you are sure to witness this softness creeping over the harbor and around the Golden Gate Bridge. You might see it at other times of the year, but summer is the most likely.

What Causes Fog

Fog famously blankets San Francisco in the summer when it's hot in inland California, east of the Pacific.  This heat creates low pressure over Northern California's Central Valley. As the hot inland air rises, the heavier cool ocean air off the Pacific rushes in to replace it. This flow of air from the high- to the low-pressure zone pulls the fog through the Golden Gate passage and into San Francisco Bay.

When and Where to Find Fog

It's common to see fog in the summer, but you can't count on it every day. So if you're looking for a romantic fog adventure, be spontaneous. Morning and evening fog rolls into San Francisco Bay pretty dependably starting in June and lasting through August.

It pushes its way through the Golden Gate Bridge towers, drifts and swirls up and over the Marin Headlands, and nestles up against shoreline piers. Most of the time, it magically stops before enveloping the city in toto. It's a picturesque show of the glory of nature that changes each day depending on the interactions of the sea, sun, and the wind across the Bay area.

Best Places to View Fog 

When the tide of fog is in, a prime way to see it, to be immersed in it, is to walk across the Golden Gate Bridge. But this is for the hearty and adventurous. If that's not you, you can get a pretty splendid view of the fog along Crissy Field, the Golden Gate Promenade, Marina Green, and Fisherman's Wharf, where the wetness and the wind may be a bit less chilling, but you'll still need to bundle up and bring along some warming hot chocolate.

For a peak experience, get yourself high above the mist on top of one of San Francisco’s hills and look down upon the shroud of fog as it overwhelms the entrance of the bay. First as wispy tendrils, then as a blanket of fleece, fog sometimes covers even the tips of the Golden Gate Bridge towers and stretches itself out into the bay. Look around at the city skyline, with its unmistakable silhouettes of Coit Tower and the Transamerica Pyramid reaching upward. You might think the word for this is "breathtaking," but that would be an understatement.