Historical Air Quality Data

Historical Air Quality Data​

Status of Ozone Pollution in Maryland

The Department has developed maps to help you visualize Maryland's air quality improvements. The maps illustrate how lower ozone levels have led to smaller problem areas. Ozone

 

8-Hour Ozone Exceedance Days

Excel DataThe annual list of the 8-hour ozone concentrations exceeding the 2008 health-based National Ambient Air Quality Standard is provided below.  Click on the appropriate check mark to download the data in Excel format.  Be advised that the counts of days reflect all monitors that are part of the non-attainment area (NAA); however, only Maryland data collected by the Department and the EPA Clean Air Status and Trends Network (CASTNET) are provided in the Excel file.  A map of NAAs shows the Maryland NAAs and surrounding jurisdictions.

Historical air quality data is also accessible at  Clean Air Partners, EPA Air Data,  and other data resources listed below.
 

 

 

Number of Days 8-Hour Ozone Concentrations Exceeded 2008 Health-Based Standard

  Baltimore, MD NAA Washington, DC-MD-VA NAA Philadelphia-Wilmington-Atlantic City, PA-DE-MD-NJ NAA State-wide Excel
2016* 12 8 12 14 *

2015

6 5 13 8 checkmark
2014 4 4 6 5
2013 4 4 9 9
2012 20 21 26 30
2011 23 20 19 29
2010 33 33 35 43
2009 10 4 8 11
2008 23 20 27 31
2007 45 43 43 54
2006 31 35 33 37
2005 34 42 40 44
2004 27 23 32 31
2003 23 23 36 28

Notes: "NAA" denotes non-attainment area, EPA CASTNET data are included since 2011.

*2016 is preliminary data and subject to change, 2016 table is being developed

 

Data Resources