Record Setting Air Quality in 2017

Air Quality Index (AQI)

  • 2017 recorded the greatest number of Good AQI days across all counties in Valley history


  • 2017 was a record setting ozone season, with the lowest number of days exceeding the 84 ppb 8-hour ozone standard
  • 2017 set a new record low ozone design value for the Valley, bringing the region closer to attaining the 84 ppb federal 8-hour ozone standard

24 Hour Pm 2.5 Standard


  • Even with air quality impacts from wildfires, the year 2017 continued the decline in PM2.5 design values, where the Valley continued to attain the 65 µg/m3 federal 24-hour PM2.5 standard, and continued to make progress toward meeting the other federal PM2.5 standards

24 Hour Pm 2.5 Standard