Air Quality Data - Unedited Hourly Concentrations

Special status notes:

IMPORTANT WINTER NOTES: ***1) Particle pollution (fine particle) levels often rise during the overnight hours. This occurs mostly on calm, clear, cold nights when inversions form and behave like a cap keeping pollution from lifting high above the surface. You can see the inversion layer because smoke from heating devices will hover like a blanket. Higher terrain will trap pollution in valleys and 'bowls'. If the air doesn't mix well during the day, or many heating devices are concentrated in a valley area, the 24 hour average of particle pollution can reach the Moderate range for the day. ***2) Coarse particles levels will rise near roadways and parking lots as the sand & salt is stirred up by winds or vehicle traffic. This is most likely in the days following a winter storm. Once the sand/salt mixture dries out it is stirred up more easily.


Use the form below to retrieve hourly air quality concentrations recorded from currently active ozone and particle (particulate matter 2.5) pollution monitoring stations across the State. This is "raw" data which has not been converted to the Air Quality Index and is "preliminary." To view past data from all sites please go to Historical Data and either select the QA'd Excel file for data from previous years or view the preliminary Excel file for data from the current year. The preliminary file is updated monthly.

View map with current data.

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