Know Before You Burn: CAL FIRE Regulations on Debris and Warming Fire

Written by

Hank Stern

As fire season intensifies in California, residents of San Mateo County must remain vigilant and informed about CAL FIRE regulations surrounding debris pile burning and warming fires. These practices, while sometimes necessary or traditional, carry significant risk and are subject to strict guidelines to protect public safety, property, and natural resources.

Debris Pile Burning: What You Need to Know

Debris burning, also known as open burning of yard waste like branches, leaves, and other vegetative material, is heavily regulated and only allowed under specific conditions. You MUST have a permit.

During certain times of the year, when fire danger is high, residential hazard reduction by burning of dead vegetation is unsafe. Homeowners should always check with CAL FIRE and the air quality management agencies before burning.

All outdoor burning must be conducted in such a way as to prevent the smoke from creating a smoke nuisance. Burning wet materials, burning in large quantities, or burning trash, produces smoke that lingers and can offend people in addition to significantly affecting air quality.

Current Status (as of late June 2025):

  • Burn Permits Required: All residential pile burning requires a valid CAL FIRE burn permit.
  • Burn Suspension Period: CAL FIRE may suspend all burn permits during the height of fire season. Always check current restrictions at burnpermit.fire.ca.gov before lighting a pile.
  • Local Authority Coordination: In addition to CAL FIRE, residents must comply with rules set by the Bay Area Air Quality Management District (BAAQMD) and San Mateo County Environmental Health.
  • Burn Day Status: Burning is only allowed on designated “Permissive Burn Days,” determined by air quality and weather conditions. The Kings Mountain area is located within the Bay Area Air District “Coast Section”. The Bay Area Air District status MUST SAY for the burn day “Burn” (not “No Burn”). Check local advisories.

Basic Requirements for Pile Burns

  • Maximum pile size: 4 ft x 4 ft
  • Supervision: A responsible adult must be in attendance with tools (shovel) and water on-site
  • Clearance: Clear all flammable material and vegetation within 10-feet of the outer edge of pile and down to the bare earth.
  • Weather: No burning shall be undertaken unless weather conditions (particularly wind) are such that burning can be considered safe.
  • Restrictions: No household trash or garbage can be burned outdoors at residences.
  • Timing: To reduce the amount of smoke when burning, you should burn between 10 a.m. and 3 p.m. when smoke dispersion conditions are best and be fully extinguished before dark (cool to the bare-hand touch)

Failure to follow these regulations may result in fines, liability for suppression costs, or criminal charges if the fire escapes and causes damage.

Warming Fires: Regulations and Safety Tips

Warming fires, often used for camping, outdoor work, or ceremonial purposes, are allowed with restrictions:

Warming Fire Guidelines

  • No permit is required for small warming fires on private property, outside of fire season restrictions, provided they are:
    1. Contained in a non-flammable fire ring;
    2. Supervised at all times; and
    3. Located at least 25 feet from structures and vegetation
  • Fires must be used solely for warmth or cooking, not disposal of waste.
  • Fires must be completely extinguished with water and stirred until cold (cool to the bare-hand touch).

Prohibited Conditions

  • During Red Flag Warnings or High Fire Danger Days, even small warming fires may be prohibited.
  • Fires on public lands or parks may require a special permit from the managing agency (e.g., California State Parks or San Mateo County Parks).

Stay Informed and Fire Safe

For more information on burn permits, fire safety, and up-to-date restrictions:

Let’s work together to keep San Mateo County safe from wildfire. One spark can start a wildfire. Always burn responsibly.

KMFD in Action!

The Kings Mountain Fire Department has been busy recently, with a variety of activities as the attached photos document. They show our Department involved in a recent Joint Agency Water Tender Drill, in a Vehicle Stabilization Training and responding to a vehicle rollover on Skyline.