Fairfax is located in Marin County, California at 37°5914N 122°3520W. It is 3.25 miles (5.2 km) west-northwest of its nearest neighbor, San Rafael. The town has a total area of 2.1 square miles (5.5 km²), all of it land. Elevation of the town is 115 feet (35 m).
Fairfax is located in the Pacific time zone, UTC-8, except during Daylight Savings Time when the zone is UTC-7).
Zip and Area Codes
Fairfax zip codes include 94930 and 94978.
Fairfax telephone area code is 415.
Climate and Soils
Fairfax's climate is mild during summer when temperatures tend to be in the 60's and cool during winter when temperatures tend to be in the 50's. The warmest month of the year is July with an average maximum temperature of 85 degrees Fahrenheit, while the coldest month of the year is December with an average minimum temperature of 40 degrees Fahrenheit.
Temperature variations between night and day tend to be relatively big during summer with a difference that can reach 31 degrees Fahrenheit, and fairly limited during winter with an average difference of 17 degrees Fahrenheit.
The annual average precipitation at Fairfax is 47.5 inches. Winter months tend to be wetter than summer months. The wettest month of the year is January with an average rainfall of 9.6 inches.
Soils in the Fairfax area mostly belong to the Tocaloma Series as classified by the U.S. Soil Conservation Service. These soils consist of moderately deep, well drained soils on uplands. These soils are typically formed from sandstone and shale and often occur on slopes ranging above 15 percent.