Air Quality

  • RAAN

    The Real-time Air Advisory Network (RAAN) is a tool to protect the health of the residents of the San Joaquin Valley. It provides hourly air quality information for your local neighborhood and allows you to take action, when necessary, to avoid poor air quality.

    • Pm 2.5 - Official EPA measurement of pollution, PM 2.5 is the particulate matter with a diameter of 2.5 micrometers or less. Smaller than a human hair and not visible to the eye it can be found in wood smoke.
    • Ozone - Official EPA measurement of pollution, ozone is a gas comprised of three oxygen atoms, formed through the interaction between NOx, VOC, and sunlight. Often a result of vehicles and other mobile sources of pollution.
    • Contact the Health Services Department for more information on possible school closures:
      • (209) 933-7060

    Click here to view the air quality forecast for Stockton

    Click here to view the air quality forecast for San Joaquin County


    Real-Time Air Advisory Network

Be mindful of air quality

  • At this time of year, when students return to school, increased vehicle traffic contributes to a rise in ground-level ozone.  Parents can help protect public health and the health of their children by reducing vehicle emissions through carpooling and turning off their engines during school pick-ups and drop-offs. In addition, Valley residents are urged to reduce vehicle emissions by driving less, driving zero-emission or low-emission vehicles, keeping their vehicles tuned up and avoiding the use of drive-through services.

    Valley air quality has shown tremendous improvement over the past several years. The progress can be attributed to a combination of the District’s many control strategies, robust incentive programs, and a commitment by Valley businesses, residents and stakeholders to reduce emissions whenever possible.

    “Thanks to the vigilance and cooperation of residents and businesses throughout the Valley, we continue to see improvements in air quality every summer,” said Samir Sheikh, the District’s Air Pollution Control Officer and Executive Director. “We urge the public to be even more mindful of their impact on air quality during this critical Back-to-School window.”

    To help ensure continued progress and minimize pollution associated with school site vehicle idling, the District has partnered with hundreds of Valley schools through the Healthy Air Living Schools program, providing signs and other resources that remind parents to “Turn the Key & Be Idle Free” when picking up or dropping off students. Healthy Air Living Schools also includes training for school staff on using the District’s Real-time Air Advisory Network (RAAN), which displays hourly air quality data and corresponding outdoor activity recommendations to protect student health.

    All Valley residents can find current, localized air quality data by visiting or downloading the free Valley Air District app from the Apple Store or Google Play. These tools allow users to save multiple locations and quickly view the air quality level at their saved locations.

    To learn more about the Healthy Air Living Schools program, request a presentation or enrollment into the program, visit or contact us at

    For more information, call a District office in Fresno (559-230-6000), Modesto (209-557-6400) or Bakersfield (661-392-5500).