RICHMOND, Va. (AP) — It was a good summer for central Virginia, at least in terms of air pollution.

The main pollutant in smog — ozone — reached unhealthy levels just one day this year. That was June 16.

That matches the one day in 2013, but is far below the 11 days in the previous two years.

Ozone levels are driven up by hot, stagnant weather, especially when they are bunched together.

The Richmond Times-Dispatch (http://bit.ly/1m9hZ58 ) reports that cold fronts often interrupted hot spells this summer. In addition, state and federal clean air programs are working.

Virginia’s ozone season runs from mid-April to late September.

___

Information from: Richmond Times-Dispatch, http://www.timesdispatch.com

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.