Background on: Wildfires

 
Overview

Fire plays an important role in the life of a forest, clearing away dead wood and undergrowth to make way for younger trees, but the risk wildfires pose to people and property is growing as more people move into forested areas once largely uninhabited. These areas, known as the Wildland-Urban Interface (WUI), contain about 44 million houses in the lower 48 states, according to the U.S. Forest Service.

Rising temperatures are also believed to contribute to large, destructive blazes. Warmer weather contributes to wildfire conditions in several ways: dryer and more combustible vegetation, more frequent lightning strikes, an extended fire season; and more intense winds.

Harvard School of Engineering and Applied Sciences researchers have concluded that by 2050 the number of wildfires in the West could rise by 50 percent, and across the U.S. the number would double.

 
Insured wildfire losses

Damage caused by fire and smoke are covered under standard homeowners, renters and business owners insurance policies and under the comprehensive portion of an auto insurance policy. Water or other damage caused by fire fighters to extinguish the fire is also covered under these policies. In California, the California FAIR Plan covers residential and commercial properties located in brush and wildfire areas. Properties in those areas are subject to higher rates due to increased risk of fire. 

 
Causes of wildfires

As many as 90 percent of wildland fires in the United States are caused by humans, according to the U.S. Department of Interior. Some human-caused fires result from campfires left unattended, the burning of debris, downed power lines, negligently discarded cigarettes and intentional acts of arson. The remaining 10 percent are started by lightning or lava.

 
Wildfire prevention and mitigation

Researchers are discovering that embers blown by the wind during wildfires cause most of the fires that burn homes. Also, homes that are less than 15 feet apart are more likely to burn in clusters. In such cases, fire is often spread by combustible fences and decks connected to houses, a study by the Insurance Institute for Business & Home Safety (IBHS) found.

Among the preventive features recommended in the IBHS study were noncombustible siding, decking and roofing materials; covered vents; and fences not connected directly to the house. In addition, combustible structures in the yard such as playground equipment should be at least 30 feet away from the house and vegetation 100 feet away.

 
Properties at risk for wildfires

According to Verisk’s 2017 Wildfire Risk Analysis 4.5 million U.S. homes were identified at high or extreme risk of wildfire, with more than 2 million in California alone.

 
Charts and graphs

 
Total Potential Exposure To Wildfire Damage By Risk Category, 2014 (1)

($ billions)

State Low Moderate High Very high
Arizona $9.64 $0.98 $1.76 $1.57
California 75.84 61.92 89.35 16.10
Colorado 18.63 11.53 14.58 13.91
Idaho 9.20 5.56 3.71 2.62
Montana 14.63 4.43 2.29 2.40
Nevada 4.24 5.19 4.57 0.16
New Mexico 11.65 4.62 7.07 2.46
Oklahoma 31.92 16.77 0.03 0.00
Oregon 8.24 9.49 11.91 3.20
Texas 59.53 147.68 48.26 6.33
Utah 2.85 3.93 0.77 0.01
Washington 84.07 18.08 2.88 0.51
Wyoming 3.68 2.62 0.49 0.33
Total, states shown $331.27 $292.81 $187.66 $49.61

(1) Reconstruction value of single-family residences at risk.

Source: CoreLogic, Inc., a data and analytics company.

View Archived Tables

 
Top 10 States At High To Extreme Wildfire Risk, 2019 (1)

 

Rank State Estimated number
of properties at risk
Rank State Percent of
properties at risk
1 California 2,048,800 1 Montana 28%
2 Texas 715,300 2 Idaho 26
3 Colorado 366,200 3 Colorado 17
4 Arizona 234,600 4 California 15
5 Idaho 171,200 5 New Mexico 14
6 Washington 154,900 6 Utah 14
7 Oklahoma 152,900 7 Wyoming 14
8 Oregon 148,800 8 Oklahoma 9
9 Utah 133,100 9 Oregon 9
10 Montana 133,000 10 Arizona 8

Source: Verisk Wildfire Risk Analytics used data from Fire Line®, Verisk's wildfire risk management tool.

View Archived Tables

 
Wildfire Losses In The United States, 2008-2017 (1)

(2017 $ millions)

(1) Adjusted for inflation by Munich Re based on the Consumer Price Index.

Source: © 2018 Munich Re, NatCatSERVICE.

View Archived Graphs

 
Natural Catastrophe Losses In The United States, 2018 (1)

($ millions)

Event Number of events (2) Fatalities Overall losses Insured losses (3)
Wildfire, heat waves, and drought 16 107 $25.4 $18.0
Tropical cyclone 5 107 30.4 15.6
Severe thunderstorm 56 66 18.8 14.1
Winter storms and cold waves 9 26 4.2 3.0
Flood, flash flood 20 49 2.6 1.2
Earthquake and geophysical 2 0 0.5 0.4
Total 108 355 $81.9 $52.3

(1) As of March, 2019.
(2) Events that have caused at least one fatality or losses of $3 million or more.
(3) Sourced from Property Claim Services based on property losses including, if applicable, agricultural, offshore, marine, aviation and National Flood Insurance Program losses and may differ from data shown elsewhere.

Source: © 2019 Munich Re, NatCatSERVICE, Property Claim Services®, a unit of ISO®, a Verisk Analytics® business.

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Top 10 States For Wildfires Ranked By Number Of Fires And By Number Of Acres Burned, 2018

 

Rank State Number of fires Rank State Number of acres burned
1 Texas 10,541 1 California 1,823,153
2 California 8,054 2 Nevada 1,001,966
3 North Carolina 3,625 3 Oregon 897,263
4 Georgia 2,572 4 Oklahoma 745,097
5 Florida 2,249 5 Idaho 604,481
6 Oregon 2,019 6 Texas 569,811
7 Arizona 2,000 7 Colorado 475,803
8 Washington 1,743 8 Utah 438,983
9 Oklahoma 1,707 9 Washington 438,834
10 Minnesota 1,344 10 Alaska 410,683

Source: National Interagency Fire Center.

View Archived Tables

 
Top 10 Costliest Wildland Fires In The United States (1)

($ millions)

      Estimated insured loss
Rank Date Name, Location Dollars when occurred In 2018 dollars (2)
1 Nov. 8-25, 2018 Camp Fire, CA (3) $8,500 - $10,500 $8,500 - $10,500
2 Oct. 8-20, 2017 Tubbs Fire, CA (3) 7,500 - 9,500 7,700-9,700
3 Nov. 8-22, 2018 Woolsey Fire, CA (3) 3,000 - 5,000 3,000 - 5,000
4 Oct. 8-20, 2017 Atlas Fire, CA (3) 2,500 - 4,500 2,600-4,600
5 Dec 4 - 23, 2017 Thomas Fire, CA (3) 1,500 - 3,500 1,530-3,600
6 Oct. 20-21, 1991 Oakland Hills Fire, CA 1,700 2,851
7 Oct. 21-24, 2007 Witch Fire, CA 1,300 1,552
8 Jul. 23-Aug. 30, 2018 Carr Fire, CA (3) $1,000 - 1,500 $1,000 - 1,500
9 Oct. 25-Nov. 4, 2003 Cedar Fire, CA 1,060 1,417
10 Oct. 25-Nov. 3, 2003 Old Fire, CA 975 1,304

(1) Property losses only for catastrophic fires. Effective January 1, 1997, ISO's Property Claim Services (PCS) unit defines catastrophes as events that cause more than $25 million in insured property damage and that affect a significant number of insureds and insurers. From 1982 to 1996, PCS used a $5 million threshold in defining catastrophes. Ranked on dollars when occurred. As of August 8, 2019.
(2) Adjusted for inflation through 2018 by the Insurance Information Institute using the GDP implicit price deflator.
(3) Insurance Information Institute estimate based on data from catastrophe risk modelers, reinsurance companies, the California Department of Insurance, and the Property Claims Services unit of Verisk Analytics.
These estimates are preliminary because the organizations involved periodically resurvey the events, and the severity of losses and other factors create a high level of uncertainty surrounding the
ultimate loss figures.

Source: Insurance Information Institute, catastrophe risk modelers, reinsurance companies, the California Department of Insurance, the Property Claim Services® (PCS®) unit of ISO®, a Verisk Analytics® company, and the U.S. Bureau of Economic Analysis.

View Archived Tables

 
Additional resources

Verisk Insurance Solutions' FireLine State Risk Report

National Interagency Fire Center

Headwaters Economics - The Rising Cost of Wildfire Protection

Insurance Institute for Business & Home Safety – Wildfire resources

National Fire Prevention Administration - Wildfire safety tips

Wildfire Hazard Potential Map

Cal Fire's ReadyforWildfire.org

© Insurance Information Institute, Inc. - ALL RIGHTS RESERVED

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