SonomaCountyRecovers: Official recovery information for Sonoma County fires

Air Quality in Sonoma County

The Sonoma County Department of Health Services is dedicated to ensuring a safe and healthy environment, and keeping the public apprised of the county’s air quality in the aftermath of the October wildfires. Debris removal and clean-up is currently underway. The safe and timely removal of fire debris is the most effective strategy to protect the health and safety of our residents and the environment. During the removal effort, our regional, state and federal partners are monitoring air quality throughout the county.  We will share information from those agencies here. 

For answers to frequently asked questions including “What precautions should residents take to prevent ash from coming into my home?” and “What can I do to ensure air quality in my home is safe?” click here.

There are three categories of air quality data that will be available:

  • Routinely collected air quality data from fixed monitors from the Bay Area Air Quality Management District (BAAQMD) and Northern Sonoma County Air Pollution Control District (NSCAPCD).
  • Supplemental air quality data from recently placed mobile monitors. This includes California Air Resources Board monitors placed at Sonoma County schools located near debris sites.
  • Debris site monitoring conducted by US Army Corps of Engineers.

How do we measure air quality?

One of the most common ways to measure air quality is by measuring particulate matter, or PM. PM refers to fine particles in the air tha are detrimental to your health. PM2.5, also called “fine particulates,” consists of particles with diameters that are less than or equal to 2.5 microns in size. To learn more aout PM2.5, click here.

Air Quality Monitoring Data

For Santa Rosa and Sebastopol: To find information on the most recent PM2.5 air quality data, please click here. You will find information on the Sonoma County Air Quality Index from 6 monitoring sites in Sonoma County (previously 7, Rohnert Park/Cotati site is now offline). This information is updated daily.

For Cloverdale, Healdsburg, and Guerneville: To find information on the most recent Air Quality Index (AQI) by the Northern Sonoma County Air Pollution Control District, please click here.

Five day forecast: If you’d like to see the current spare the air status and five day forecast, please click here.

The Bay Area Air Quality Management District developed this legend to help you understand the PM2.5 data. As established by the U.S. Environmental Protection Agency (EPA), the Air Quality Index for PM2.5 is based on 24-hour concentrations, so hourly readings are only estimates.

Air Quality Index Levels of Health ConcernNumerical
Good0 to 50
Moderate51 to 100
Unhealthy for Sensitive Groups101 to 150
Unhealthy151 to 200
Very Unhealthy201 to 300
Hazardous301 to 500


During northern California’s wildfire season, the Bay Area Air Quality Management District monitors general air quality in the Bay Area and will issue a health advisory if wildfire smoke appears to be causing elevated levels of particulate pollution in the region.

The Sonoma County Department of Health Services received community and area monitoring data from the US Army Corps of Engineers (USACE). The USACE is one of several agencies in Sonoma County conducting air monitoring to ensure the safety of the community. On November 15, there were 3 active community air monitoring sites on or near Old Redwood Hwy, located between Kaiser Santa Rosa and Cardinal Newman. The PM2.5 Daily Average (measured in mg/m^3) readings were 0.004, 0.004, and 0.007. The Target Criteria is 0.5. There is no reportable risk based on particulates as a result of these readings. The USACE is also conducting area monitoring as part of debris management and clean-up. At one site in Sonoma County, the total dust perimeter (measured in mg/m^3) had non-detectable levels, meaning that there is no human health concern associated with debris removal activities.

Additional air quality data will be updated on this website as soon as it becomes available from partner agencies.

What do we currently know about air quality in Sonoma County since the October 2017 wildfires?

Recent air quality measurements from active monitors throughout Sonoma County have demonstrated “Good” Air Quality Index (AQI) numbers. The exception to this were two monitors, one at Rincon Valley Middle School (Badger Rd) and one at Matanzas Middle School (Yulupa Ave) that California Air Resources Board found to be malfunctioning. These monitors are now operational. (Updated 11.14.17 with the most recent data available).

*This website is actively being developed and updated with additional information. Information is subject to change.
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