Contra Costa County

County in California

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Report created October 27, 2026 at www.firezones.info/county/013/contra-costa

  • Fire hazard severity zones

    Share of the land in each CAL FIRE hazard class

    17% Very High

    Most of the Very High land is in the State Responsibility Area, where the State Fire Marshal's zones apply.

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  • Fire history

    Share of the land inside a recorded wildfire perimeter

    7% has burned

    Most recently the 2025 Somersville Fire, which burned 358 acres here, one of 78 fires on record.

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  • Power line fire risk

    Share of the land in the High Fire-Threat District

    18% Extreme

    Utilities may shut off power in the CPUC High Fire-Threat District in fire weather, and homes outside it can lose power when their lines run through it.

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Land by hazard class

  1. Very High 84,869 acres · 68,853 state, 16,016 local 17%
  2. High 148,084 acres · 118,583 state, 29,501 local 30%
  3. Moderate 31,083 acres · 4,630 state, 26,453 local 6%
  4. Non-wildland 210,810 acres · Local Responsibility Area 43%
  5. Not mapped by CAL FIRE 11,735 acres · Mostly federal land 2%

486,581 acres of land in all, 192,066 in the State Responsibility Area and 282,780 in the Local. State zones are the ones the State Fire Marshal designated, in effect since 1 April 2024. Local zones are CAL FIRE's 2025 recommendation, which each city or county adopts by ordinance and can make stricter. How to read fire zones

Largest fires

  1. 1977 Mitchell Canyon Fire 4,859 acres
  2. 2020 Scu Lightning Complex Of 396,824 acres in all · Cause: Lightning 3,306 acres
  3. 2013 Morgan Fire Cause: Miscellaneous 3,107 acres
  4. 1981 Blackhawk Fire Cause: Arson 2,360 acres
  5. 1967 Vasco Fire 1,398 acres
  6. 1998 Greenridge #6 Fire Cause: Power lines 1,388 acres
  7. 1961 State Park #2 Fire 1,241 acres
  8. 1958 Marsh Creek Fire 975 acres
  9. 1961 Roadside #1 Fire 856 acres
  10. 1979 Black Diamond Peak Fire 681 acres

And 68 smaller fires. In all, 31,788 acres of Contra Costa County have burned. Acres are the land each fire burned here, and fires that crossed less than an acre are not counted. Some older or smaller fires may be missing, and a fire perimeter can include unburned patches. How to read fire history

Sources

Fire hazard severity zones
CAL FIRE Office of the State Fire Marshal
State map published 27 June 2025, local map 2 February 2026
Fire history
CAL FIRE Fire and Resource Assessment Program
Published 28 July 2026
Power line fire risk
California Public Utilities Commission
Published 23 February 2026

This site is independent and not affiliated with CAL FIRE or the CPUC, so for an official determination, check with the agency or your city or county. How we read the data

Nearby areas

Cities and towns in Contra Costa County

Unincorporated communities in Contra Costa County

ZIP codes in Contra Costa County

48

Neighboring counties

  1. Contra Costa County 17% Very High · this area
  2. Alameda County 25% Very High
  3. Sacramento County 26% Moderate · <1% Very High
  4. San Joaquin County 10% Moderate · 4% Very High
  5. Solano County 6% Very High