Wildfire in the hills of southern California

Wildfire Facts: 9 Things to Know

By Kelly Butler

A wildfire is a large, uncontrolled inferno that burns intensely and quickly spreads through wild landscapes. When these blazes reach civilization, they can destroy homes and put people’s lives in danger. If you live in an area prone to wildfires, it’s important to understand what causes these infernos, how they spread, and the risks they present. Here are some interesting facts about wildfires that you should know.

Facts About Wildfires

Fact #1 — Humans cause nearly 85% of wildfires

What causes wildfires? While wildfires can start naturally from lightning strikes and spontaneous combustion of dry fuel, the U.S. Department of Agriculture reports that humans cause nearly 85% of wildfires in the United States. Examples of this activity include leaving campfires unattended, improperly disposing of cigarettes, knocking over powerlines, burning debris, and committing arson.

Additionally, climate change contributes to wildfires. According to the U.S. Energy Information Administration, the United States emitted 5,130 million metric tons of carbon dioxide into the Earth’s atmosphere in 2019. These carbon dioxide emissions trap heat, causing average temperatures around the globe to rise. As a result, droughts are becoming more frequent and lasting longer, which means more heat and drier fuel to trigger combustion and potentially start a wildfire.

Fact #2 — Wildfires need heat, fuel, and oxygen to start

Wildfires require three essential components— i.e., the fire triangle — to start and continue:

  • Fuel — Fuel can be any combustible material such as woods, paper, fabrics, and oil.
  • Heat — A heat source such as the sun, a hot bolt of lightning, or a lit cigarette will increase the fuel’s temperature to the point of ignition.
  • Oxygen — Earth’s atmosphere comprises approximately 21% oxygen. Most fires require at least 16% oxygen to burn, so that’s enough to trigger a fire if the other two components are present. When the fuel burns, it reacts with oxygen to release heat and generate combustion products like smoke and embers.

Fact #3 — Dry conditions increase the risk of wildfires

Wildfires thrive in dry, arid climates and drought-ridden locations because these areas are brimming with flammable materials like dead plants and dry vegetation. Additionally, some evergreen trees, like pine trees, have flammable oils that can burn when exposed to heat.

Fact #4 — How fast can a forest fire travel? Wildfires can travel at a rate of up to 14.27 miles per hour

Wildfires need fuel, heat, and oxygen to begin and stay alive, but they require strong winds to spread the flames and cause further destruction. Once the wildfire begins and spreads, it can travel at a rate of up to 6.7 miles per hour in forests and up to 14.27 miles per hour in grasslands. In 2017, the Thomas Fire in California spread so quickly that it moved at a rate equivalent to a football field per second.

Why Californians Need To Take Heed?

Fact #5 — Nearly one-third of California’s population is at risk of wildfires

According to data from the U.S. Census, California has approximately 11.2 million people living in the wildland-urban interface (WUI) — the area where houses are in or near wildland vegetation. When the vegetation dries out in the WUI, it puts all those people in the line of a potential wildfire. If you live in the WUI, it’s important to prepare for wildfire season by creating an emergency plan and making your home as fireproof as possible.

Fact #6 — Wildfire season in California is generally between June and October

When is wildfire season in California? Traditionally, California’s wildfire season spans from late spring through fall, typically peaking between June and October. However, due to climate change and prolonged drought conditions, the wildfire season has started earlier and ended later in recent years. It’s also important to note that wildfires are possible year-round, but the greatest risk is between June and October.

Fact #7 — Many ecosystems depend on wildfires for their survival

Wildfires can become catastrophic when they reach the wildland-urban interface. However, naturally occurring wildfires are a normal part of many ecosystems. For example, mature forests and grasslands can get too crowded for new plants to thrive. When a wildfire occurs, it consumes old, dead material and clears away competitive species. The wildfire aftermath enables important nutrients to return to the soil and provides a new, healthy beginning for plants and animals. Understanding how wildfires affect the environment helps us recognize their role in maintaining ecological balance and promoting biodiversity.

Fact #8 — Oaks, manzanitas, and succulents are key fire-resistant plants

In California, incorporating fire-resistant plants into landscaping, especially in the wildland-urban interface, can create defensible space that helps reduce the spread of wildfires and protect properties from fire damage. Consider certain species of oaks, manzanitas, and succulents, which can survive and even thrive in wildfire-prone environments. These plants often have thicker bark, high moisture content, and the ability to resprout quickly after a fire.

Fact #9 — Only you can prevent wildfires

While this famous phrase popularized by Smokey Bear may seem cliche, it still holds true after all these years, especially considering humans cause almost 85% of wildfires. When it comes to learning how to prevent wildfires, here are some key tips to remember

  • Properly extinguish campfires: Always ensure campfires are completely extinguished before leaving the area by dousing them with water, stirring the ashes, and repeating the process until the ashes are cool to the touch.
  • Follow local regulations: Abide by fire restrictions and guidelines, especially during high-risk conditions such as dry, windy weather.
  • Maintain defensible space: Create and maintain a defensible space of at least 100 feet around your home by removing dead vegetation, trimming tree branches, and keeping grass and shrubs well-watered and trimmed.
  • Dispose of cigarettes properly: Never discard cigarette butts on the ground or out of car windows. Use designated ashtrays and dispose of them responsibly.
  • Use equipment safely: Avoid using equipment that can generate sparks, such as chainsaws or lawnmowers, during high-risk periods. Ensure that any equipment used outdoors has spark arresters.
  • Practice safe burning: If burning debris, follow local regulations and only burn when conditions are safe. Never leave a burn pile unattended and have water and tools ready to control the fire if needed.
  • Educate others: Spread awareness about wildfire prevention by educating friends, family, and community members about safe practices and the importance of preventing human-caused wildfires.

Whether you live in California or another state where wildfires happen, it’s crucial to protect your family and property when disaster strikes. One of the best ways to get peace of mind during wildfire season is to purchase homeowners insurance from Mercury. We’ll work with you to create a home insurance policy that helps keep you and your family protected during the wildfire season.

Mercury Insurance offers wildfire mitigation discounts to California homeowners living in wildfire prone regions. Homeowners who take one or more steps to harden their homes against wildfires or live in a community recognized by the National Fire Protection Association® (NFPA) as a Firewise USA® site will be eligible to receive discounts of up to 18%. For more information about protecting your family, pets and property from violent and deadly firestorms, read Mercury’s FAQ Guide and visit these websites:


FIRESafe Council

Firewise USA

IBHS Wildfire Prepared Home

Contact us today for a fast, free quote.

Kelly Butler

VP, Chief Underwriting Officer for Mercury Insurance

Kelly Butler is the VP, Chief Underwriting Officer for Mercury Insurance, where she is responsible for combining analytics with traditional underwriting to evaluate wildfire risk and exposure. Her wildfire training includes the completion of a two-day National Fire Protection Association course “Assessing Structure Ignition Potential From Wildfire,” which identifies the most effective mitigation techniques. Glover received a BA in Marketing and an MBA from CSU Fullerton.

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