Diamond Bar

City in Los Angeles County

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Report created October 27, 2026 at www.firezones.info/community/19192/diamond-bar

  • Fire hazard severity zones

    Share of the land in each CAL FIRE hazard class

    36% Very High

    Most of the Very High land is in the Local Responsibility Area, where the City of Diamond Bar adopts the zones CAL FIRE recommends.

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  • Fire history

    Share of the land inside a recorded wildfire perimeter

    29% has burned

    Most recently the 2022 Cut Off Fire, which burned 2 acres here, one of 25 fires on record.

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  • Power line fire risk

    Share of the land in the High Fire-Threat District

    27% Elevated · 2% 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 3,429 acres · <1 state, 3,429 local 36%
  2. High 1,925 acres · Local Responsibility Area 20%
  3. Moderate 743 acres · Local Responsibility Area 8%
  4. Non-wildland 3,427 acres · Local Responsibility Area 36%

9,525 acres of land in all, <1 in the State Responsibility Area and 9,525 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. 1946 Diamond F141 Fire 919 acres
  2. 1929 Kelly No. 41 Fire Of 1,347 acres in all 740 acres
  3. 1972 Golden Springs Fire 718 acres
  4. 1957 Unnamed fire Of 281 acres in all 121 acres
  5. 1947 Arnold No. 106 Fire Of 1,907 acres in all 111 acres
  6. 1968 San Leandero Fire 103 acres
  7. 1974 Unnamed fire 102 acres
  8. 1928 Diamond No. 101 Fire Of 261 acres in all 92 acres
  9. 1988 Diamond Bar Fire Of 119 acres in all 84 acres
  10. 2009 Diamond Fire Of 155 acres in all · Cause: Vehicle 80 acres

And 15 smaller fires. In all, 2,775 acres of Diamond Bar 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

ZIP codes in Diamond Bar

Neighboring communities

  1. Diamond Bar 36% Very High · this area
  2. Chino Hills 73% Very High
  3. Industry 11% High · 3% Very High
  4. Pomona 11% High · <1% Very High
  5. Rowland Heights 55% Very High
  6. Walnut 15% Very High