When is the best time to visit San Francisco or "Fog City"?

The question you rather should ask in San Francisco is: When to not visit San Francisco or "Fog City"? 

And the nickname "Fog City" brings us right to the topic! I have to say that I actually love our fog as it is quite a phenomenon but I understand that tourists might disagree: as they wouldn't be able to spot Golden Gate Bridge, the top of Transamerica Pyramid, more than a white wall on top of Coit Tower or freeze in their shorts although it is July.

So why are the months between June to August so foggy and cold? 

The frequency of fog and clouds which feel as if they walk right through the city is due to California’s extraordinary geography.

In general, the state has a Mediterranean climate, with mild, wet winters and dry summers. But that general type is locally modified by special features of the landscape. The Golden Gate is the only complete breach in the Coast Range, which borders the Pacific for most of California’s length. The city is bordered on three sides by water, framed like a jewel between the Pacific Ocean and the San Francisco Bay. As a result, the Bay Region is the meeting place of continental and oceanic air masses. Through the funnel of the Golden Gate and San Francisco Bay, the immense aerial forces of sea and land wage a continual war, and the tide of battle often flows back and forth with regularity. The line between the two types of air masses, particularly in summer, may zigzag through the streets of San Francisco and extend in similarly erratic fashion across the entire region.

Meanwhile, the summer temperatures of surrounding cities, like those in the East and North Bay can cook in the summer months, with temperatures easily reaching into the low 90s to low 100s F (32.22-37.78 C). The heat produced by inland temperatures, combined with the cool water of the Bay and Pacific Ocean, and the winds coming in from the water, turn San Francisco into a paradise for lovers of fog. North Bay and South Bay residents also benefit from fog creeping in at night to cool down hot temperatures.

Makes sense, right? That is the reason for our awesome summer fog! So if you want to visit and have a lot of sun: best time is the Indian Summer between September and Oktober!

Enjoy your trip!