Air Quality in Redwood City


  • Unfortunately, large-scale fires are becoming more common. Even when fires burn hundreds of miles away, the impact on the air here in the Bay Area can be felt for days, sometimes weeks.

    RCSD follows guidelines set forth in the School Air Quality Activity Recommendations, which is a document developed with guidance from the California Department of Education for all California schools.

Keeping Track of Air Quality

Air Quality Index Scale

  • Green (0-50 Good) 

    • Maintain regular school routines.
    • Continue outdoor recess, lunch and P.E. 

    Yellow (51-100 Moderate)  

    • Maintain regular school routines.
    • Continue outdoor recess, lunch and P.E.
    • Ensure that sensitive individuals are medically managing their condition.*

    Orange (101-150 Unhealthy for Sensitive Groups)         

    • Open classroom doors and windows, as needed.
    • Provide indoor and outdoor options during lunch and recess, with reminders to reduce physical exertion.
    • Sensitive individuals should exercise indoors or avoid vigorous outdoor activities.*

    Red (Unhealthy) 

    • Exercise indoors or limit vigorous outdoor activities to a maximum of 15 minutes.
    • Sensitive individuals should remain indoors.*
    • Consider whether or not after-school activities scheduled for the outdoors should be canceled or changed. 

    Purple (Very Unhealthy)

    • Health alert: the risk of health effects is increased for everyone.
    • No outdoor activity. All activities should be moved indoors.
    • School closures may occur depending on guidance from the San Mateo County Health Department.

    Maroon (Hazardous)

    • Health warning of emergency conditions: everyone is more likely to be affected.
    • No outdoor activity. All activities should be moved indoors. School closures may occur.
    • School closures may occur depending on guidance from the San Mateo County Health Department.

    *​​Sensitive Individuals include all those with asthma or other heart/lung conditions. Please inform your child's teacher and the school office staff of any significant health concerns for your child(ren), especially those who may have respiratory challenges due to allergies, asthma, recent upper respiratory infections, etc., as we will be taking extra care with these students. ​​​​​​​

    RCSD families should know that the district prioritizes schools remaining open. Individual parents are the best judges of the conditions under which their students should attend school when schools remain open during days with poor air quality. Parents and guardians may keep their children at home on poor air quality days. This is an excused absence.

Poor Air Quality and COVID-19

  • During healthy to moderate air quality days, RCSD typically keeps its doors and windows open and pulls fresh air in from the outside through its HVAC system. During poor air quality days, those practices change in order to avoid pulling smoky, unhealthy air into the classroom. Even with windows and doors closed and air recirculating, the high quality filters, the additional HEPA filtration systems included in each space, and the use of masks sufficiently reduces the spread of the COVID virus. 

    The San Mateo County Pandemic Recovery Framework (PRF), the document all San Mateo schools currently use for public health guidelines, affirms that with the proper ventilation students and staff can remain indoors safely with windows and doors closed and ventilation systems set on “recirculating,” instead of pulling air from the outside.

    The district will continue to abide by the protocols and require masks indoors onsite on poor air quality days. Should the AQI reach unhealthy levels, the district may dismiss school early to avoid any maskless time indoors.


  • What resources does RCSD use to make decisions about air quality and our response?

  • At what point will RCSD keep students indoors due to air quality concerns?

  • How does RCSD monitor students who are considered a “sensitive group?”

  • When the Air Quality Index (AQI) is concerning while children are at school, what further measures will RCSD take to decrease exposure?

  • What steps can parents take to support their child during poor air quality?

  • Can parents keep their children home during periods of poor air quality and will the absence be excused?

  • Under what conditions and when will RCSD Schools be closed due to poor air quality?

  • Are RCSD staff required to report to work under conditions of poor air quality and what accommodations can be made for their safety?

  • Will RCSD be required to “make up” days that schools are closed?

  • Where can parents go to find the latest information from RCSD regarding Air Quality and school closures?

  • How does COVID affect the district's air quality protocols?

  • To whom should parents and staff direct questions or provide input regarding air quality and school closures?