Air Quality Conditions During Wildfires

Wildfire smoke can travel thousands of miles from the source of the fire.

Wildfire smoke alert on air.utah.gov:

“Smoke from wildfires could cause high concentrations of particulates. If smoke becomes thick, persons with existing heart or respiratory ailments should reduce physical exertion and outdoor activity.”

The Division of Air Quality (DAQ) provides updates on current conditions, a three-day forecast, and a trend chart of pollution levels for particulates, ozone, nitrogen oxides, and carbon monoxide. DAQ updates the current conditions hourly for 12 counties in Utah: Box Elder, Cache, Carbon, Davis, Duchesne, Iron Salt Lake, Tooele, Uintah, Utah, Washington, and Weber. These updates show levels of fine particulates (PM2.5) and ozone levels. For mobile updates, download the UtahAir App for iPhone or Android.

Visibility Index

Smoke levels can change rapidly, and visual observations can help those with health issues know what precautions to take. Individuals can make visual observations using the 5-3-1 visibility index. If the outlines of trees are visible on the horizon, the fire is less than five miles away. After establishing the distance, follow this simple guide from the Oregon Department of Environmental Quality:

  • If visibility is well over five miles, the air quality is generally good.
  • Even if visibility is five miles away but generally hazy, air quality is moderate/beginning to deteriorate but generally healthy. The air quality may not be healthy, however, forr smoke-sensitive individuals. You should avoid prolonged exposure if conditions are smoky to the point where visibility is closer to the 5-mile range.
  • If under five miles, the air quality is unhealthy for young children, adults over age 65, pregnant women, and people with heart and/or lung disease, asthma or other respiratory illness. These people should minimize outdoor activity.
  • If under three miles, the air quality is unhealthy for everyone. Young children, adults over age 65, pregnant women, and people with heart and/or lung disease, asthma or other respiratory illness. These people should minimize outdoor activity.
  • If under one mile, the air quality is unhealthy for everyone. Everybody should avoid all outdoor activities.
Air Quality Visibility (in Miles) Particulate Matter Levels (1 hr. avg., parts per million) Cautionary Statement
Good 10 miles 0-40 None
Moderate 6 to 9 miles 41-80 Unusually sensitive individuals, including those with heart or respiratory disease, should pay attention to symptoms and should consider limiting prolonged or heavy exertion.
Unhealthy for Sensitive Groups 3 to 5 miles 81-175 People with respiratory or heart disease, the elderly, and children should limit prolonged exertion and stay indoors when possible.
Unhealthy 1.5 to 2.5 miles 176-300 People with respiratory or heart disease, the elderly, and children should avoid prolonged exertion and stay indoors when possible; everyone else should limit prolonged exertion.
Very Unhealthy 1 to 1.25 miles 301-500 People with respiratory or heart disease, the elderly, and children should avoid any outdoor activity. Everyone else should avoid any outdoor exertion.
Hazardous 0.75 miles or less Over 500 Everyone should avoid all outdoor exertion and should remain indoors whenever possible.