To view the current ozone readings from our monitors located at city hall in downtown Nevada City and at the Grass Valley Charter School, please click on the links below:

• One Hour Average Ozone for Grass Valley, Nevada City & other Locations
• One Minute Average Ozone for Grass Valley & Nevada City

Due to the complex terrain in our area and its impact on local wind patterns, ozone levels can vary significantly over short distances. Therefore, when viewing these graphs it is important to remember that these ozone readings are only representative of the immediate area near the monitor locations.

Please check the “Latest data” time at the top of the graphs to make sure you are seeing the most current ozone readings, and if the “Latest data” time is not current, then click on your browser’s ‘refresh’ button to get the most recent readings.

The Northern Sierra Air Quality Management District calibrates the Litton Building monitor every Friday morning, causing very high ozone readings to appear in our plots. These readings are not real and should be disregarded.

STA in NC would like to thank the following organizations and individuals for their assistance in bringing this ozone data to you in real-time:

• Nevada City and the staff at city hall for hosting one of our ozone monitors and helping with its installation.
• Brian Martinez and his staff at the Grass Valley Charter School for providing a home for our second ozone monitor.
• The Northern Sierra Air Quality Management District for calibrating our ozone monitors to ensure that we are providing the most accurate data possible to the public.
• Mike Anderson and ClientWorks for installation help and technical assistance, and Spiral of Nevada City for early help with the network.