Ozone forms in the air when nitrogen oxides react with hydrocarbons on warm, sunny days with little wind. While it was once North Carolina’s most widespread air quality concern and contributed to breathing problems, ozone continues to decline due to steady reductions in emissions from its primary air pollution sources: power plants, industry and motor vehicles. In 2017, the U.S. Environmental Protection Agency designated North Carolina as attaining the 2015 ozone standard statewide. Since then, North Carolina has maintained compliance with the standard.

The DAQ air quality forecast, available at airquality.climate.ncsu.edu/air, gives users up-to-date localized forecasting for 91 North Carolina counties and two Ridge Top zones, including the next day’s forecast.