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Wildfire Causes

Wildfires pose a serious threat to public safety, property and our natural resources. Over 98% of all wildfires in Wisconsin are caused by people. Knowing the common fire causes, understanding the conditions under which fires can start and spread, and taking appropriate action can greatly increase your chances of preventing an unwanted fire.


Debris burning is the number one cause of wildfires in Wisconsin. The first step to prevent a debris-burning caused wildfire is to always consider alternatives to burning. If burning is your preferred option, then learning what to do before, during and after your burn will significantly decrease your chances of starting a wildfire.

Most debris fires occur in the spring after the snow-cover melts and prior to vegetation greening. Spring is when people are outside doing yard clean-up and then choosing to burn leaves, brush and pine needles.

If you choose to burn, follow these simple guidelines to ensure you are burning safely.

Before burning

  • Obtain proper burn permits and follow any restrictions.
  • Comply with local ordinances that may be more restrictive than state law.
  • Make certain you are only burning legal materials.
  • Keep an eye on the weather and avoid burning under windy conditions.
  • Make certain the area adjacent to the fire is free of all flammables.

During burning

  • Have a water source and firefighting tools handy, like a shovel or rake.
  • Keep the size of the fire small and manageable.
  • Maintain a mineral soil firebreak around the burn area.
  • Never leave your fire unattended.
  • If weather conditions change for the worst, put the fire out immediately.
  • If your fire escapes, dial 911 immediately!

After burning

  • Make sure the burn is completely out before leaving.
  • Use lots of water, drown, stir and repeat until cold.
  • Go back and check again later for any remaining smoke or embers.
  • Fun fact: use cold ashes from your burn as a bed for your garden. It makes a great fertilizer!

Consider waiting until the ground is completely snow-covered. Throw a tarp over materials and wait until snow accumulates and will remain on the ground for the duration of your burn.


Properly maintained and safe use of outdoor equipment and vehicles can greatly reduce the chances of sparking a wildfire. Equipment fires account for nearly 1/3 of Wisconsin's wildfires. The majority of them are caused by sparks or hot exhaust systems from logging, farming equipment and off-road recreational vehicles.

The general rule of thumb is to be aware of dry conditions, avoid use during these times and properly maintain equipment and vehicles by thorough cleaning of debris and routine mechanical checks.


Motorists are responsible for many wildfires sparked along roadways. Nearly all of these fire starts could be prevented by following these safety recommendations.

  • Secure chains
    • Practice safe towing; dragging chains can throw sparks.
    • Use appropriate safety pins and hitch ball to secure chains.
  • Look for dragging parts
    • Make sure your vehicle is properly maintained with nothing dragging on the ground.
  • Check tire pressure
    • Maintain proper tire pressure; driving on exposed wheel rims will throw sparks.
    • Carry a fire extinguisher in your vehicle and learn how to properly use it.
    • Don't drive your vehicle onto dry grass or brush; hot exhaust pipes, catalytic converters and mufflers can start fires that you won't even see until it's too late!
  • Maintain brakes
    • Brakes worn too thin may cause metal to metal contact which can cause a spark.

Outdoor equipment

Learn how to use outdoor equipment properly to help keep from sparking a wildfire.

  • Mowing
    • During dry periods, conduct mowing operations in the morning hours, but never when it's windy or excessively dry.
    • Avoid mowing dry grass and weeds.
    • Watch out for rocks near mowing operations; metal blades can strike rocks and create sparks.
  • Spark arrestors
    • In wildland areas, spark arrestors are required on all portable gasoline-powered equipment (e.g. tractors, harvesters, chainsaws, mowers, ATV's, etc.).
    • Keep the exhaust system and spark arrestors in good working order and free of carbon buildup.
    • Use the recommended grade of fuel and don't top off to cause a spill.
  • Equipment operations
    • Grinding and welding operations in wooded or grassy areas should allow for good clearance from surrounding vegetation.
    • Avoid driving vehicles on dry grass or brush; hot exhaust pipes and mufflers can start fires.
    • Keep a shovel and fire extinguisher handy. If a fire escapes your control, dial 911 immediately.


The first step in campfire safety is to understand the difference between a campfire and a fire to dispose of debris. Campfires, solely for warming or cooking purposes, are smaller in size and comprised of clean and dry wood, contained within a designated fire ring or surrounded by rocks. Campfires are allowed anytime, except when Emergency Burning Restrictions are in effect. Burning in a fire ring with the intent to eliminate debris is not a campfire and does require a burning permit in DNR protection areas.

No matter what type of outdoor fire you have, check the daily burning restrictions for your area before ignition and never leave a fire unattended. Remember, you may be held responsible for all suppression costs and potentially any damages associated.


  • Select a level, open location away from prevailing winds and fuels such as logs, brush, leaves and needles.
  • Have easy access to water.
  • The space above your fire must be free from any overhanging branches.
  • Scrape away the surface area right down to mineral soil or non-combustible material.
  • If not in a designated fire ring or pit, scoop a depression in the center of the cleared area and surround with rocks.
  • The fire should be built no larger than necessary for cooking or personal warmth.
  • Now comes the fun part—choosing between three different kinds of campfires [PDF].


  • Keep a shovel and water source nearby at all times.
  • Never leave your campfire unattended.
  • Keep an eye on the weather and extinguish if conditions become less favorable.
  • Never leave children around a fire unattended.
  • If your fire escapes, dial 911 immediately.


  • Use the "drown, stir and feel" method:
    1. Drown the fire with water.
    2. Stir around the fire area with a shovel to wet any remaining embers.
    3. Feel the area with the back of your hand to ensure nothing is still smoldering.
  • Stir the ashes and turn the wood with a shovel to uncover hot coals. This will cool the fire faster and allow the water to soak in better.
  • Move some dirt onto the fire site and mix thoroughly to fully smother it.
  • Drown your fire with water as soon as possible after use; the ground will cool faster and the hazard to surrounding trees or shrubs will be greatly reduced.
  • If you circled your campfire with rocks, make sure the rocks are not hiding any hot coals.
  • Drown it again! Make sure the fire is completely cold before leaving the site.

The majority of campfire-caused wildfires in Wisconsin are a result of the person responsible leaving the fire before it was properly extinguished. Never cover your campfire with dirt and walk away from it. This creates a "Dutch oven" and coals may remain hot for days or weeks until conditions are ripe for the fire to escape.


Most wildfires caused by fireworks occur during the weeks leading up to and after the July 4th holiday or under extended drought conditions. Wildfires can start anytime the ground is not completely snow-covered, but it is important to be especially cautious with fireworks and all fires when the fire danger is elevated and fires spread quickly and burn more intensely, especially in the spring and during summer drought periods.

The reality is, all fireworks have the potential to cause a wildfire. While exploding and airborne fireworks are the most hazardous, even sparklers, fountains and smoke bombs can cause an ignition.

The safest way to enjoy fireworks is to attend a public fireworks show put on by professionals instead of setting off your own. Always keep a safe distance and remember to never allow young children to use fireworks.

Before using fire of any kind in the outdoors:

  • know the daily fire danger;
  • obtain the proper permits;
  • choose a safe area free of flammable materials;
  • have water and tools nearby; and
  • make certain fireworks are completely out and cold before leaving.

Know the consequences

Enforcement of fireworks violations rests with local law enforcement agencies. Department of Natural Resources officers will enforce fireworks laws when the user has caused a wildfire or poses a direct threat of fire to the wildland. Anyone found responsible for causing a wildfire is liable for all suppression costs and may be liable for up to twice the cost of damages. In addition, the DNR prohibits the use of all fireworks on state lands including state parks, state forests and state owned public hunting and fishing properties.

Obtain permits

In Wisconsin, fireworks are regulated and it is best to check with local officials before purchasing and lighting them. Depending on the specific type of fireworks, a permit may be required.

In very general terms, if it "goes up" or "blows up" it most likely requires a permit. A user's permit to possess and use fireworks can be obtained from the mayor of the city, president of the village or chairperson of the town or their designee based on the jurisdiction in which the possession or use is to occur.

Wood heat devices

Cleaning out hot ashes from wood stoves and fireplaces and discarding them into wooded or grassy areas or sparks from the chimney of a wood boiler can cause an unwanted wildfire and easily threaten your home and property.

More and more people are turning to alternative wood heat devices to heat homes and other structures. These devices include fireplaces, wood stoves and outdoor wood boilers. What many people do not know is that under snow-free conditions, typically vegetation is dry and prime fuel for a wildfire to occur if given an ignition source.


Properly dispose of hot ashes from your fireplace or wood stove by:

  • emptying ashes in a metal container with a tight-fitting lid;
  • letting embers cool by drowning and stirring the ashes with plenty of water and a shovel; and
  • since embers can remain hot for days, avoid disposing of ashes in the outdoors unless the ground is completely snow-covered and will remain so for days to come.

Wood boilers

Properly maintain outdoor wood boilers for safe operation by:

  • removing all flammable vegetation surrounding your outdoor wood boiler;
  • routinely cleaning stacks to reduce chances of built-up debris from escaping; and
  • installing a chimney stack screen to prevent sparks and embers from escaping (consult vendor for recommendations).

Other causes

There are additional ways that wildfires can start.


Arson is a crime capable of destroying property and threatening the lives of citizens as well as the firefighters that have to respond to and fight these fires. Arson fires also hurt the environment and the economy as they burn wildlife habitat, prime recreation areas and valuable natural resources.

Arson-caused wildfires can be prevented with the help of the general public. If you see something...say something. Citizen information is often critical in helping solve a crime. Immediately notify local law enforcement authorities, the DNR office or call the arson hotline.

Information that helps investigators includes:

  • exact location and time of suspicious activity;
  • vehicle make, model, color and license plate number;
  • height and build of person, including hair color and length, type and color of clothing;
  • distinguishing characteristics such as facial hair, scars and tattoos; and
  • any unusual clothing or jewelry.

Wisconsin's arson hotline is sponsored by the Wisconsin Arson Insurance Council [exit DNR] and is available 24 hours a day. Callers can remain anonymous. The toll-free number is 1-800-362-3005. Arsonists will be prosecuted aggressively. If convicted, a person could pay as much as a $10,000 fine and face more than three years in prison. They also are held liable for the cost of suppression, damage to natural resources and any personal property that may be destroyed.

Power lines

Trees growing under and near power lines can be a hazardous combination. Dead or dying trees can easily fall on power lines near your home and cause sparks. On windy and dry days, typically in the spring, these sparks can quickly become a wildfire and threaten the safety of people living near the power line. In addition, downed power lines are also a major risk to emergency services.

Never attempt to extinguish a fire near power lines, no matter how small the fire. Even if the power line is on the ground, it may still be energized.

Power utilities and electric cooperatives have thousands of miles of right-of-ways in the state. Many run through forested areas where the utility keeps a clear right-of-way. It is the mutual benefit of the utilities and the public that power line rights-of-way be maintained to prevent both power outages and wildfires.

Trees outside of the right-of-way may also need to be removed if they are dead, dying or diseased and in danger of falling on the power line. Defective and diseased trees or limbs can fall and cause broken conductors or short circuits on power lines.

It is important for property owners to look around and report dead and dying trees or overhanging branches near power lines. Before cutting down a tree near electric lines, be sure to contact the utility company. Touching a tree limb in contact with an electric line is extremely hazardous and life-threatening.


Historically railroads were a major cause of wildfires that started from improperly maintained brake shoes, spark arrestors and hot carbon expelled from the locomotive. Over the last several decades, the railroad industry has significantly improved fire prevention efforts to reduce railroad-caused fires. However, railroads still cause wildfires, especially on steep grades and near corners where heavy acceleration or braking occurs.

While the general public can not necessarily prevent these fires, they can report smoke along the tracks and provide a good description of where the smoke is seen. Due to railroad safety issues, it is not recommended for the public to investigate the exact location of the smoke, but it is better to provide the location of the nearest crossing for first responders. Every railroad crossing should have an Emergency Notification sign [exit DNR]. The sign is blue with white lettering and has an 800 number to call as well as a unique DOT crossing identification number to report that location. If the sign is missing or if in doubt, call 911.

Landowners that have property near the railroad right-of-way, especially in areas where fires have occurred in the past, can assist emergency services by making sure to maintain cleared access area to the railroad right-of-way. The quicker the first responders can get to the fire, the smaller the fire will be. In addition, creating or maintaining a fire break or defensible space between the railroad right of way and landowner property may also keep fires smaller and reduce the damage to property by both the fire and the suppression equipment needed to extinguish the fires.


Smoking materials such as cigars, cigarettes and pipes, as well as the matches used to light these items all have the ability to start a wildfire if discarded in the outdoors if the fire danger is elevated. Smoking-caused fires can easily be prevented if materials are properly discarded in vehicles, ash trays or designed smoking trash receptacles. If smoking in the outdoors, consider smoking on pavement or gravel and crush smokes until they are out cold.

Under Emergency Burning Restrictions, burning of any combustible material outdoors, including smoking materials, is prohibited. These restrictions are implemented under abnormally dry conditions.