California Annual Temperatures and Records

California Temperature Records

Hottest temperature ever recorded: 134 F, Death Valley, southeastern California, 7/10/1913 Coldest temperature ever recorded: -45 F F, Boca, east-central California, 1/20/1937 Hottest location ranked by highest average annual temperature: Death Valley, southeastern California, 76.7 F Coldest location ranked by lowest average annual temperature: Twin Lakes, west-central California, 40.5 F Eureka, California possesses one of the least variable climates in California, based on temperature. The record high is only 87 degrees and the record cold temperature is 26 degrees. The city averages no days above 90F annually and and only 6 days below 32F. On September 27, 2010, Downtown Los Angeles experienced it hottest day since records began in 1877. At 12:15pm, the thermometer hit 113 degrees, breaking the previous high of 112 set on June 26th, 1990. Shortly after reaching the record, the National Weather Service's thermometer broke. Although it was quickly replaced with another one, it's possible the temperature rose above 113 degrees, but it was not recorded.

 

The lowest temperature recorded in California was at Boca, at elevation 5,532 feet in Nevada County, when a reading of -45° F was observed on January 20, 1937. At Boca, where temperatures of 21° F or colder have been recorded in every month of the year, the long-term average minimum for January is 11. Greenland Ranch, on the other hand, at an elevation of 168 feet below sea level, has reported a maximum temperature of 134° F. This is the highest temperature observed anywhere in the United States, and occurred on July 10, 1913. This is an area where temperatures are persistently high throughout the summer. In the summer of 1917, there were 43 consecutive days with maximum readings of 120° F or higher at Greenland Ranch.

There is a trend toward temperature uniformity from day to day and from season to season on the ocean side of the Coast Range and in coastal valleys. East of the Sierra Nevada, temperature patterns are continental in character with wide excursions from high readings to low. Between the two mountain chains and over much of the desert area, the temperature regime is intermediate between maritime and continental air masses. Hot summers are the rule while winters are moderate to cold. 

In the basins and valleys adjoining the coast, climate is subject to wide variations within short distances as a result of the influence of topography on the circulation of marine air. The Los Angeles Basin and the San Francisco Bay area offer many varieties of climate within a few miles. In the Bay area, for example, the average maximum temperature in July is about 65° F at Half Moon Bay on the coast, 87 at Walnut Creek 25 miles inland, and 93 at Tracy, another 25 miles inland. Santa Monica Pier, in the Los Angeles area, enjoys a normal July maximum of around 69° F, while the average increases to 95° F at Canoga Park in the San Fernando Valley just 15 miles to the north.

California precipitation averages and extremes, Los Angeles, San Francisco, San Diego and San Jose climate records and averages,
California average freeze dates, precipitation/ temperature data for all U.S. states and Top 10 U.S. climate extremes
Data source: National Climatic Data Center