Official reports show embers ignite between 60% and 90% of homes lost in wildfires. This article explains how ember-related house fires happen, and we'll outline steps that a homeowner can take to reduce their fire risks.
California’s Office of the State Fire Marshal explains that “embers are the most common cause of home ignition”.
According to Cal Fire's 2025 report, 'Building In The Wildland', “between 60 to 90 percent of home ignitions occur because of embers”.
Source: fire.ca.gov
Yes, flames can burn down homes, too, but airborne embers are often what start the flames.
November 28, 2008, embers destroyed 480 of 600 homes in this mobile‑home park near Sylmar, California. The photograph by Michael Mancino for FEMA shows how embers can wipe out entire neighborhoods; as a U.S. government work, the image is public domain View photo: https://commons.wikimedia.org/wiki/File:Burned_mobile_home_neighborhood_in_California.jpg
United States Ember Research
California's Office of the State Fire Marshal states that 60-90% of home ignitions come from embers.
The CA Fire Marshal stated that 'most homes burned in wildfires catch fire from embers, not direct flames or heat.'
Source:
osfm.fire.ca.gov
The image is by State Farm and is licensed CC BY 2.0 commons.wikimedia.org. View photo: https://commons.wikimedia.org/wiki/File:Home_burned_and_destroyed_by_wildfire_in_Colorado.jpg
Studies from major universities back up the fact that embers, not flames, are the most dangerous thing to a neighborhood.
A University of Idaho report notes that over 90% of wildland-urban interface home ignitions were caused by flying embers.
Source:
uidaho.edu
The University of Nevada also confirms embers cause up to 90% of home ignitions.
Source:
unr.edu
Canadian Observations on Embers
Canadian wildfire experts report similar findings to the United States'.
FireSmart Canada estimates about 90% of homes destroyed by wildfires ignite from embers, not direct flames.
Source: firesmartalberta.ca
This example video shows how embers that can enter a home's exposed vents; the vent's existing 1/4" metal mesh is insufficient for stopping dangerous fire embers from entering the home's attic space. 1/8" mesh, or smaller, is recommended for ember-related risk reduction.
A 2019 Insurance Institute study also found embers caused up to 90% of building ignitions.
Canadian wildfire guides highlight embers as the main threat to homes.
Source:
firesmartbc.ca
Australian Bushfire & U.S. Ember Data
Australian bushfire studies show most homes are lost due to embers igniting nearby materials.
Australian fire authorities warn that wind-blown embers ("ember attack") can travel hundreds of meters ahead of fires.
Studies of the 2009 Black Saturday fires confirmed embers caused most home losses.
Source:
qra.qld.gov.au
The U.S. Forest Service and California Fire Safe Council define 'dangerous embers' as “small pieces of burning material that can travel more than a mile ahead of a wildfire”.
Dangerous wildfire embers can “create spot fires when they land on combustible materials, such as leaves in your gutter or plants under your windows,” according to Humbolt County's official fire research.
Source:
humboldtgov.org
Fire and Rescue NSW firefighters work to save a burning house in Werombi, South West Sydney"– Photographed 6 December 2019 by Helitak430 Licensed CC BY‑SA 4.0 commons.wikimedia.org. View photo: https://commons.wikimedia.org/wiki/File:Bushfire_destroys_house.jpg
Evidence From Major Fires in California
California wildfires provide clear examples of ember damage:
- Cedar Fire (2003), San Diego County: Embers ignited roof debris, decks, and yard materials.
- Tubbs Fire (2017), Sonoma & Napa Counties: Embers started home fires far ahead of the main flames.
- Glass Fire (2020), Napa & Sonoma Counties: Showed the need for ember-free zones around homes.
Research on the Witch & Guejito Fires (2007) found embers ignited about 75% of destroyed homes.
An aerial photo shows rows of burned houses in the Rancho Bernardo, California. The image was taken by Andrea Booher for FEMA and is in the public domain View photo: https://commons.wikimedia.org/wiki/File:FEMA_-_33404_-_Aerial_of_burned_homes_in_California.jpg
How Homeowners Can Protect Homes
Roofs and Gutters
Cal Fire’s 2025 Home-Hardening guide notes that “your roof is one of the most vulnerable areas of your home” because its large surface area “is more susceptible to embers and flame,”
Source: fire.ca.gov
Based on this evidence, here are key steps to protect your home:
- Install a Class A fire-resistant roof to block ember ignition.
- Clean gutters regularly and use metal gutter covers to prevent debris buildup.
Vents and Openings
In the 2025 Home Hardening guide, Cal Fire warns that “attic and underfloor vents with openings larger than 1/8 inch are susceptible to embers” .
Cal Fire's official recommendation is to cover your home's vunerable, exterior vents with “noncombustible, corrosion‑resistant metal mesh between 1/16 and 1/8 inch in diameter,”.
Source: fire.ca.gov
- Cover vents with 1/8-inch or finer 'Ember Mesh' screens to block embers.
- Use metal covers on dryer vents and other openings.
- Cover under-deck areas with 1/8-inch or finer 'Ember Mesh' screens to block embers.
Fences and Gates
Cal Fire instructs homeowners to “replace attached combustible fencing or gates with a noncombustible option for the first 8 feet” which can effectively break the fire pathway.
Source: fire.ca.gov
- Build decks with non-flammable materials or solid surfaces.
- Avoid wooden fences attached to your home.
Defensible Space
Firefighters United for Safety, Ethics & Ecology are quoted as saying:
“large tree trunks close to your house are not a fire hazard – think how long it would take a green log to ignite in your fireplace! But the leaves, needles, and twigs that trees drop are a major problem. Keep your big trees, but prune branches back from your roof."
Source: fusee.org
- Create a non-flammable zone within 5 feet of your home by removing plants, mulch, and debris.
- Regularly clear dead grass, leaves, and branches from your yard.
Windows and Doors
Cal Fire advises homeowners to “install or upgrade to double‑pane tempered glass windows”.
“Tempered glass is about four times more resistant to breaking during a wildfire,” according to Cal Fire's 2025 Home-Hardening guide.
Source: fire.ca.gov
- Install dual-pane tempered glass windows to resist heat.
- Choose metal or fire-resistant doors.
Taking these steps can greatly reduce your risk of losing your home to wildfire.
You can check your property's wildfire risk today, using TotalScreen's free quiz called 'BurnRisk'.
Summary
Across North America, Australia, and other wildfire-prone regions, studies confirm embers ignite 60-90% of homes lost in wildfires.
This explains why fire safety programs focus on ember-resistant design and creating defensible space.
Preventing ember ignitions is the most-effective way to protect homes during wildfires.
Sources:
- California Office of the State Fire Marshal: osfm.fire.ca.gov
- 'Building In The Wildland' Guide: https://osfm.fire.ca.gov//building-in-the-wildland
- 'Home Hardening' Guide - CAL FIRE - https://www.fire.ca.gov/home-hardening
- University of Idaho Extension: uidaho.edu
- University of Nevada, Reno Extension: unr.edu
- FireSmart Alberta: firesmartalberta.ca
- FireSmart BC: firesmartbc.ca
- Queensland Fire and Emergency Services: qra.qld.gov.au