Shadows of The City
Mark Twain, who lived in San Francisco for several years, is famously misquoted as saying that the coldest winter he ever spent was a summer in San Francisco. The city has a very cool climate similar to those seen in parts of the Mediterranean. A jacket is almost always a good idea here. The annual average temperature is around 60F (16C), and rarely varies more than 15 degrees from that average. Annual humidity is 84%. In the summer months, the weather tends to be clear and sunny; in winter, cloudy and overcast. The winter is also when the city gets the bulk of its precipitation, typically in the form of rain.
Like everything else, though, the weather in San Francisco varies. On the western and northern sides of the city, the weather tends to be cooler, cloudier, and wetter. Sunset, Richmond, the Presidio, and Marina all fit this description. The eastern and southern neighborhoods, by contrast, tend to be more sunny and dry. And no discussion of climate could be complete without mentioning the fog. Few cities are associated with fog as much as San Francisco. How many other cities have a daily fog forecast? In summer, the fog comes in thick and billowing along the western side of the city in the evening, and often persists until the middle of the following day. In winter, the fog tends to cling to the ground in northern neighborhoods, and is often accompanied by drizzling rain.