Morristown National Historical Park is located approximately 30 miles from New York City in one of the most densely populated areas in the country.

Air quality elements are not measured in the park and air quality information is provided by the State of New Jersey from nearby monitoring stations.

The eight hour health standard for ozone is occasionally exceeded at the Chester, New Jersey air quality monitoring station located approximately ten miles from the park.  Overall, during the last decade the air quality in New Jersey has been improving.