San Bruno from Spanish ' St. The population was 43, at the United States Census. It is approximately 12 miles 19 km south of Downtown San Francisco. According to the United States Census Bureau , the city has a total area of 5. The city spreads from the mostly flat lowlands near San Francisco Bay into the foothills of the Santa Cruz Mountains , which rise to more than feet m above sea level in Crestmoor and more than feet m above sea level in Portola Highlands. San Bruno City Hall sits at an official elevation of 41 feet 12 m above sea level.
Portions of Mills Park, Crestmoor, and Rollingwood are very hilly, featuring canyons and ravines. Creeks, many of them now in culverts, flow from springs in the hills toward San Francisco Bay.
San Bruno has a mild Mediterranean climate characterized by mild to warm, dry summers and cool, wet winters. San Bruno has much milder temperatures than most of the state. Owing to its relatively mild temperatures, the city's climate closely resembles that of an oceanic climate. Since , the National Weather Service formerly the U. According to the official records, January is the coldest month with an average high of Freezing temperatures occur on an average of only 1.
There was 1. September is the warmest month with an average high of Fog and low overcast are common during the night and morning hours in the summer months, which are generally very dry except for occasional light drizzle from the fog. On rare occasions moisture moving up from tropical storms has produced thunderstorms or showers in the summer.
Gusty westerly winds are also common in the afternoon during the summer. Due to thermal inversions , summer temperatures in the higher hills are often much higher than at the airport. Thunderstorms occur several times a year, mostly during the winter months, but are usually quite brief. Total annual precipitation, most of which falls from November to April, ranges from Nylund for the U.
