What is a Wildfire?

A wildfire is a large, uncontrolled fire that burns through areas such as fields, forests, and grasslands. In addition to causing significant damage to ecosystems and wildlife, wildfires can also spread into areas populated by humans, potentially causing serious damage to property and putting lives at risk. Wildfires can burn for days or even weeks and spread to thousands of acres.

Wildfire - number of fires and acres burned in the United States

What is the Wildlife Urban Interface (WUI) and Why Does it Matter?

The Wildlife Urban Interface (WUI) is the transition area between human developments and wild, unoccupied areas. So, it might be where a forest meets the backyards of houses in a neighborhood, or where a grassland meets a strip mall. WUI areas are often designed to offer a barrier region between residential communities and wild spaces that protects homes from the ravages of wildfires. Buffer zones provide an area of reduced vegetation to separate residential areas from highly flammable wild spaces. However, these buffer zones are decreasing quickly as more homes are built in or near WUI areas.

There are more than 46 million residences in America that are in the WUI area. The WUI is a critical zone because many people who own properties in these areas are at an increased risk of having their properties suffer wildfire-induced losses, as well as injury or loss of life. These areas typically contain high amounts of dense vegetation which can become a conduit for the quick spread of wildfire through residential properties. Unlike urban areas, the WUI typically does not contain features such as parking lots and roads which could act as impediments to wildfires, slowing their spread.

Causes of Wildfires in the U.S.

Wildfires may be triggered by natural events, but many are started as a result of human activities. more than 80 percent of wildfires are caused by humans according to recent studies. They are especially likely to spread in areas being affected by drought. During drought conditions, the natural materials that fuel wildfires can dry out and become more flammable and prone to ignition.

Natural causes of wildfires include:

  • Lighting strikes
  • Volcanic eruptions
  • Spontaneous combustion of dry leaves, brush, or twigs on extremely hot days

Human causes of wildfires include:

  • Discarded cigarettes, cigars, and matches
  • Unattended campfires and fireworks
  • Arson and other illegal fire use
  • Sparks from power lines, railroads, vehicle crashes, and vehicle exhaust

Wildfire Risk in the U.S.

Wildfire risk is based on the level of hazard of the fire and the vulnerability of property to the conditions of the blaze. According to the USDA, hazard risk is based on the likelihood and intensity of the fire, while vulnerability is based on exposure and susceptibility to fire conditions.

To calculate property risk, factors include: geographical region, climate, and likelihood of ignition. In addition, living within a WUI can increase a property’s exposure to the effects of wildfire. Properties which border wilderness areas can be quickly affected by a fire spreading from that area of high burn risk. Close access to dense vegetation can increase the intensity of the wildfire by providing the conditions for the rapid and deadly spread of flames.

The Western U.S. is especially vulnerable to wildfires. California, Texas, Colorado, and Arizona tend to have more wildfires than other states. This is largely due to their dry climates and in the case of California, Texas, and Arizona, their hot weather.

The top ten states that are the most at risk for people to experience wildfire-related property damages are:

What are the Effects of Wildfires?

Despite technological progress and advanced firefighting techniques, wildfires routinely cause devastation across America. In 2018, there were more than 58,000 individual wildfires in America. Fires temporarily destroy forests, farmland, fields, wildlife and other rural habitats.

They can destroy buildings and claim lives as a result of suffocation, injuries, and/or burns. Between 1998 and 2017, wildfires and volcanic activity around the world killed 2400 people. The smoke and CO2 released by fires can increase pollution and cause extremely hazardous health conditions.

Financial losses resulting from wildfires are also extremely severe. Annual wildfire losses in America range from $63.5 billion to $285 billion. These losses cause a major problem on a national, regional, and local level. Communities at a high risk to wildfires can suffer losses to their infrastructure, businesses, and tourism industries.

How is Climate Change Increasing Wildfire Risk?

Climate change is severely increasing the devastating effects of wildfires. Climate and vegetation conditions are crucial factors for the severity and likelihood of fire. The warmer and dryer conditions created by climate change are causing increased drought and longer fire seasons.

Research has shown that climate change doubled the annual number of wildfires that occurred between 1984 and 2015.

Once fires start, warmer temperatures and a dry climate make them significantly harder to put out. Increased precipitation during winter results in more scrub growth, and increased vegetation caused by longer and drier summers provides fuel for hotter and faster moving fires.

Wildfires also produce large amounts of CO2, which is a greenhouse gas that directly contributes to climate change. In fact, in California alone in 2020, over 112 million metric tons of CO2 were released into the air from wildfires. That is the equivalent of adding 24 million cars to the road for a year and that’s just one state. As wildfires worsen due to the effects of climate change, they also directly contribute to a changing climate by adding hundreds of millions of metric tons of CO2 into the atmosphere each year.

Wildfire Risk Mitigation Options for Homeowners

All homeowners need to be aware of the risk of loss that wildfires pose. However, this is especially true for homeowners who live in states prone to fire or homeowners who live in the wildlife urban interface (WUI).

Here are some of the actions you can take to reduce your property’s vulnerability to wildfire damage. Many of these fire mitigation options focus on creating a zone of decreased vegetation and fire-resistant materials surrounding your home:

Fireproof your yard.

  • Remove dead branches and fallen leaves from your yard
  • Trim large plants and trees regularly, remove trees less than 5 to 10 feet away from your house
  • Water your lawn and keep groundcover below 4 inches in height, use stone or gravel instead of organic mulch
  • Make sure that the gutters are routinely cleared of debris
  • Keep stashes of firewood at least 30 feet away from the house and other flammable items stored inside or away from your home

Build or replace with appropriate materials.

  • Use roofing and siding materials that have a class A fire rating
  • Replace flammable outdoor furniture with non-flammable outdoor furniture

Taking these precautions can go a long way towards helping you to reduce the risk of your property being damaged by a fire. But unfortunately, even taking all of these mitigation actions will not be able to completely protect your home from risk in the case of extreme fire conditions. Making an emergency fire plan is therefore an essential precaution to protect the lives of you and your family members in the case that fire threatens your property.

Know the risks in your area and have an action plan.

  • Be aware of when it is fire season, sign up for notifications on fire conditions from local authorities, and take into account increased severity due to climate change
  • Have each family member make a plan including safe places to meet, paths of escape from incoming fire, and emergency forms of communication
  • Gather an emergency supply kit and keep it easily accessible in case you need to evacuate

Mitigation options are an important part of reducing the likelihood of wildfire damage in your community. But with climate change rapidly increasing the risks of fire for many in the U.S., homeowners should also consider insurance.

Purchase appropriate homeowners insurance.

  • Check with your insurance agent to make sure that you have the appropriate level of coverage for your area and risk level


In order to prevent the spread of wildfires, each of us is responsible for managing our use of fire in a responsible way. Fires started by human carelessness result in severe damage, loss of property, and human life every year.

Assessing your personal risk through the ClimateCheck property report can assist in the determination of what mitigation and insurance options are best for your home.

Read More About Wildfire Risks