Air Quality

While prescribed fires have proven to be very successful in creating the conditions necessary for healthy forests and rangelands, there is a troublesome side effect of smoke.

To minimize the impacts of smoke, land managers work closely with the Environmental Protection Agency (EPA) and the Idaho Department of Environmental Quality (DEQ) in both planning and implementing prescribed fires.

To ensure that air quality meets federal and state standards and to lessen impacts from smoke while prescribed fires are being conducted, federal and state public land managers and regulatory agencies in Idaho and Montana have formed a partnership, known as the “Montana/Idaho State Airshed Group.” Before prescribed fires are ignited, public land managers in Idaho and Montana submit their plans to the Montana/Idaho State Airshed Group Monitoring Unit, based in Missoula, Montana. The monitoring unit reviews existing air quality levels along with weather conditions to determine which prescribed fires can be ignited and which, if any, must be delayed to ensure that air quality meets federal and state standards. If air quality approaches unhealthy levels, public land managers delay igniting prescribed fires. For more information about the Montana/Idaho State Airshed Group, visit their web site at

Restrictions on prescribed burning are imposed when the 24- hour average air quality measurements exceed or are likely to exceed the National Ambient Air Quality Standards for PM 2.5 micrometers established under the Clean Air Act and revisions. As part of statewide emergency practices, DEQ can restrict open burning, including prescribed fire when PM levels are reached and likely to persist. The emergency practices are designed to protect the health and safety of the public, especially sensitive people that are likely to be affected by higher concentrations of PM.

To ensure smoke dispersion during prescribed fires, land managers monitor atmospheric conditions closely before prescribed fires are ignited. Factors evaluated include air movement, wind direction and speed, atmospheric stability, and long-range weather forecasts. Yet even in favorable conditions, the air will still become smoky. Often, although the air is smoky, it still meets federal and state air quality standards.

Daily Air Quality Reports for communities throughout the state can be found on the DEQ website at: