Current Air Quality

air quality chart

Air Quality Monitoring


  • The US Environmental Protection Agency provides the current Air Quality Index (AQI) or in free AirNow smartphone app for Tuolumne County for ozone and an air quality forecast for the next day for only ozone.  
  • During the wildfire season, to access the AQI for wildfire smoke, please use the following link: https://gispub.epa.gov/airnow/; click on PM2.5 in the Monitor and Contour (NowCast AQI fields) and scroll into California and the Motherlode for current levels.  
  • The California Air Resources Board (CARB) alsoreports current ozone levels in downtown Sonora and throughout California on its ozone map. 
  • Recent and historic air quality data recorded by CARB is also available. 
  • The National Oceanic and Atmospheric Administration (NOAA) provides an air quality forecast map for the United States.
what is new

On May 6, 2024, the updated U.S. Air Quality Index (AQI) for fine particle pollution takes effect. Starting that day, information you see on the AirNow website, the AirNow Fire and Smoke Map and the AirNow smartphone app will reflect the updated AQI.

The updated AQI does not mean your air quality is worsening. EPA updated the AQI because they have learned more about the health impacts of particle pollution.

What can you expect to see when the updated AQI takes effect? In many areas, you may see air quality reach the Moderate AQI category (Code Yellow) more frequently than in the past.

EPA does not expect significant increases in Code Orange or Code Red days. However, when events like wildfires are affecting your air, you may see more days in the Very Unhealthy (Code Purple) or Hazardous (Code Maroon) categories than in the past.

 

Learn more about the AQI changes at https://www.epa.gov/system/files/documents/2024-02/pm-naaqs-air-quality-index-fact-sheet.pdf

Check your current air quality and next-day AQI forecast at https://www.airnow.gov, or in the free AirNow smartphone app.