Frostline.info

Frost line depth in California

Estimated frost depth in typical soil runs from 0″ to 29″ across California's 58 counties. Pick your county or enter a ZIP code for a local estimate.

Deepest frost

  1. Modoc County 29″
  2. Lassen County 28″
  3. Plumas County 26″
  4. Sierra County 26″
  5. Mono County 24″

Mildest

  1. Ventura County 0″
  2. Santa Cruz County 0″
  3. Santa Barbara County 0″
  4. San Mateo County 0″
  5. San Luis Obispo County 0″

Frost depth by county

CountyEst. frost (typical soil)Typical code range
Alameda County1″12″ minimum
Alpine County18″18–24″
Amador County4″12″ minimum
Butte County6″12–18″
Calaveras County7″12–18″
Colusa County3″12″ minimum
Contra Costa County2″12″ minimum
Del Norte County3″12″ minimum
El Dorado County12″12–18″
Fresno County6″12–18″
Glenn County3″12″ minimum
Humboldt County2″12″ minimum
Imperial County0″12″ minimum
Inyo County14″12–18″
Kern County4″12″ minimum
Kings County1″12″ minimum
Lake County3″12″ minimum
Lassen County28″24–36″
Los Angeles County2″12″ minimum
Madera County10″12–18″
Marin County0″12″ minimum
Mariposa County10″12–18″
Mendocino County2″12″ minimum
Merced County1″12″ minimum
Modoc County29″24–36″
Mono County24″24–30″
Monterey County1″12″ minimum
Napa County1″12″ minimum
Nevada County14″12–18″
Orange County0″12″ minimum
Placer County8″12–18″
Plumas County26″24–36″
Riverside County2″12″ minimum
Sacramento County2″12″ minimum
San Benito County1″12″ minimum
San Bernardino County4″12″ minimum
San Diego County3″12″ minimum
San Francisco County0″12″ minimum
San Joaquin County1″12″ minimum
San Luis Obispo County0″12″ minimum
San Mateo County0″12″ minimum
Santa Barbara County0″12″ minimum
Santa Clara County3″12″ minimum
Santa Cruz County0″12″ minimum
Shasta County15″12–18″
Sierra County26″24–36″
Siskiyou County17″18–24″
Solano County1″12″ minimum
Sonoma County1″12″ minimum
Stanislaus County2″12″ minimum
Sutter County2″12″ minimum
Tehama County14″12–18″
Trinity County9″12–18″
Tulare County5″12–18″
Tuolumne County7″12–18″
Ventura County0″12″ minimum
Yolo County2″12″ minimum
Yuba County7″12–18″

Common questions

What is the frost line depth in California?

It ranges from about 0 inches in the mildest county to 29 inches in the coldest, in typical soil.

Which California county has the deepest frost?

Modoc County, at about 29 inches in typical soil.