Janesville

Summary

• Fire hazard severity zones

  Share of the land in each CAL FIRE hazard class

  Map
  1. Very High 4,508 acres · State Responsibility Area 21%
  2. High 6,268 acres · 5,503 state, 765 local 29%
  3. Moderate 828 acres · 641 state, 187 local 4%
  4. Non-wildland 6,133 acres · Local Responsibility Area 28%
  5. Not mapped by CAL FIRE 3,917 acres · Mostly federal land 18%

  21,654 acres of land in all, 10,652 in the State Responsibility Area and 7,085 in the Local. State zones are the ones the State Fire Marshal designated, in effect since April 1, 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

• Fire history

  The 10 largest of 11 fires that burned here

  Map
  1. 1944 Unnamed fire 716 acres here
  2. 1973 Sunnyside Dump #3 Fire 640 acres here
  3. 1985 Bass Fire 2,382 acres in total · Cause: Equipment use 508 acres here
  4. 1927 Unnamed fire 725 acres in total 486 acres here
  5. 2003 A-3 Fire 1,051 acres in total · Cause: Equipment use 468 acres here
  6. 2018 Hyatt Fire 432 acres in total · Cause: Playing with fire 299 acres here
  7. 2010 Sunnyside Fire 231 acres in total · Cause: Lightning 186 acres here
  8. 1996 Byers Fire 1,019 acres in total 151 acres here
  9. 2025 Byers Fire 105 acres in total · Cause: Miscellaneous 87 acres here
  10. 1933 Unnamed fire 914 acres in total 54 acres here

  And 1 smaller fire. The most recent was the 2025 Byers Fire, which burned 87 acres here. In all, 3,456 acres of Janesville 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