Winter wood smoke ordinance goes into effect Friday Oct. 1. Burning prohibited in Multnomah County through March 1 on days when air quality is forecasted to be poor

September 29, 2021

Multnomah County’s winter wood smoke ordinance goes into effect Friday, Oct, 1, and prohibits  wood burning on days when air quality is forecasted to be poor. 

But as we leave behind a scorching summer, slog our way into a soggy fall, and enter our 20th month of the global COVID-19 pandemic, health officials are once again asking residents to avoid burning wood whenever possible as a way to support neighbors with health conditions that make it more difficult for them to breathe in less healthy air.

Poor air quality and smoke can also worsen symptoms of COVID-19. A dry cough, sore throat and difficulty breathing are symptoms common to both COVID-19 and smoke inhalation. People in good health can also feel health effects from wood smoke, and may interpret those to be symptoms of COVID-19. 

“We’re all looking for those creature comforts, ways to feel comforted and cozy. A mug of hot chocolate, fluffy slippers or curling up under a blanket are great options this winter,” said Nadège Dubuisson, an Air Quality Coordinator with the Multnomah County Health Department. “We’re asking people to consider alternatives to a wood fire, because adding smoke to the air, on any day, can make someone else’s day so much worse.”

Multnomah County’s winter wood smoke ordinance is in effect annually from Oct. 1 through March 1. This is the fourth full year of Multnomah County’s wood smoke ordinance. Last year, officials issued 34 “Yellow Day” voluntary curtailments and no “Red Day” burn restrictions. Since the ordinance has been in effect, three “Red” wood burning restriction days have been issued.

During these colder months, homeowners, renters and businesses in Multnomah County cannot use wood stoves, use fireplaces or burn outdoors on days when the air quality is forecasted to be poor. This includes burning wood in:

  • Wood stoves
  • Fireplaces
  • Outdoor fire pits
  • Chimeneas

If an exemption is filed, wood burning can be allowed for people who use wood exclusively to heat their homes or who are on limited incomes. Wood burning is also permitted during emergencies such as a power outage. And there are no restrictions on using wood or charcoal for cooking. 

Every year, Multnomah County regulates wood smoke during the cooler months because wood smoke from home heating accounts for more than half of our fine particle pollution on the average winter day.

Air quality can be especially poor during days of still air and temperature inversions — when cold air is trapped close to the ground. The rule helps protect people who are most vulnerable to poor air quality: children, seniors and people with asthma and other serious breathing conditions. 

How it Works

From Oct. 1 through March 1, officials at Multnomah County Environmental Health will conduct daily forecasting in cooperation with the Oregon Department of Environmental Quality and the National Weather Service to identify potential poor air quality days.

When conditions suggest more pollution and an upcoming inversion (which causes air to become stagnant and trap pollutants close to the ground), Multnomah County will issue burn advisories or burn restrictions by 11 a.m. The restriction will then take effect at noon and remain in effect for 24 hours, unless an extension is warranted.

Officials will publish all mandatory curtailment notices on the county’s Wood Smoke website, share the notice through social media, including Facebook and Twitter, and push out any burn restriction notices (red days) on Public Alerts (sign up here) and NextDoor.

You can also sign up to receive email alerts about all voluntary (yellow) and mandatory (red) curtailment notices. Or you can call 503-988-0035. 

On some days, the dial might show an arrow pointed to “yellow,” meaning “air quality is moderate,” suggesting a voluntary curtailment for that day. Rarely, when air quality and weather conditions are both very bad, that same dial will point to “red”: “Air quality is unhealthy. Burn restriction.”

During a curtailment period, people can report a suspected violation to Environmental Health by calling 503-988-0035 or emailing

If you must burn to stay warm, apply for a yearly exemption, available at

Why we need a rule

Poor air quality disproportionately affects children, seniors and people with existing health conditions. Short-term exposure to wood smoke can aggravate asthma, bronchitis and lung disease. And long-term exposure has been linked to cancer and higher rates of infant mortality.

After cars and truck emissions, residential wood smoke is the largest contributor to cancer risks from air pollution. Wood stoves, pellet stoves and outdoor fires account for 11 percent of the area’s total cancer risk from air pollution, while industrial emissions account for about 1 percent of the estimated cancer risk from air toxics in Multnomah County. 

[View Multnomah County’s air toxics and cancer risk assessment]

Multnomah County’s rule represents an effort to protect public health and also help the County remain in compliance with federal laws even as the population grows. The U.S. Environmental Protection Agency regulates six air pollutants, including particulate matter. In recent years the airshed that includes Multnomah County has come close to exceeding its limit on particulate matter 2.5. Washington County, Eugene, Medford, Klamath Falls and Pendleton have all passed similar ordinances as local jurisdictions struggle to remain in compliance with federal air pollution limits.

If you must burn for heat, follow these steps to help reduce the output of harmful wood smoke:

  • Burn dry, seasoned wood that has been split, stacked, covered and stored.
  • Test wood with a moisture meter before burning (20% moisture or less is best).
  • Use a cleaner-burning EPA- or DEQ-certified gas or wood stove.
  • Burn small, hot fires. Provide sufficient air to the fire; never let it smolder.

Learn more about what you can do to reduce wood smoke at

In addition to avoiding fires on days with poor air quality, you can also help limit air pollution on those days by avoiding the use of gas-powered equipment like leaf blowers and by avoiding driving.