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Maryland State Government Maryland Department of the Environment

Ambient Air Monitoring Program

The Ambient Air Monitoring Program measures ground-level concentrations of criteria pollutants and air toxics, along with surface and aloft meteorological parameters. The Program also performs quality control, quality assurance, and analysis of the pollutant concentrations that are measured at each of the air monitoring stations located throughout Maryland. It is responsible for Air Quality Index (AQI) reporting and issuing daily air quality forecasts as well as coordination of 3D air-shed photochemical grid and dispersion modeling.

In addition, the Program collaborates with local universities to conduct special atmospheric monitoring research to better characterize aloft and surface atmospheric pollutant concentrations. These research initiatives support air quality planning and regulations development.

Learn More:

To report an environmental emergency, see Emergency Numbers.

Air Quality Forecast Discussion:

Warm and humid conditions persist on Wednesday but cloud cover and scattered rain will keep ozone in check. Fine particles will remain on the Good/Moderate threshold along the I-95 corridor with the ample humidity. While clouds are expected to dominate the region Thursday and Friday, breaks in cloud cover could allow ozone to rise locally, particularly as a cold front stalls and weakens as it moves in to Maryland. Where the front finally stalls out and fades will determine the overall outcome of pollution concentrations. Due to the present uncertainties, Moderate AQI for ozone has been reintroduced for the Thursday and Friday forecasts. Should cloud cover dominate, fine particles at the Good/Moderate threshold will instead be the leading pollutant as ozone retreats to the Good range. - MDE

If you have any questions, please contact Janice Lafon at 410-537-3280 or e-mail at so that she may direct your inquiry.