Is the air quality good in the affected locations?
On June 5, 2026, air quality is not considered good across multiple regions of the United States due to elevated ground-level ozone concentrations (1).
Code Orange Air Quality Alerts and Air Quality Action Days have been issued for parts of North Carolina, South Carolina, Maryland, Virginia, Georgia, Delaware, New Jersey, Pennsylvania, New York, Connecticut, Indiana, Ohio, and Kentucky.
These alerts indicate that air pollution levels may become unhealthy for sensitive groups, including children, older adults, and people with asthma, heart disease, or other respiratory conditions.
Areas under alert include:
- Charlotte, Concord, and Kannapolis, North Carolina
- Winston-Salem, Greensboro, and High Point, North Carolina
- Greenville and Spartanburg, South Carolina
- Atlanta, Georgia
- Northern Virginia
- District of Columbia
- Baltimore and Annapolis, Maryland
- Philadelphia metropolitan area
- New York City metropolitan area
- Parts of Connecticut, Delaware, New Jersey, Indiana, Ohio, and Kentucky
The air quality alerts are being issued from numerous state-level and county-level environmental departments, like the North Carolina Department of Environmental Quality and the Forsyth County Office of Environmental Assistance and Protection in Winson Salem, North Carolina (2).
Residents in these areas should monitor local air quality conditions and limit prolonged or strenuous outdoor activity during the afternoon and early evening hours, when ozone concentrations are typically highest.
When will air quality improve in the affected locations?
Air quality is expected to improve after the current alerts expire, most of which end during the evening hours of June 5, 2026, or by midnight local time.
Ground-level ozone concentrations generally decrease after sunset as temperatures cool and the sunlight needed for ozone formation diminishes. Improved atmospheric mixing and changing weather conditions may also help disperse pollutants.
However, additional alerts may be issued if similar weather patterns persist. Residents should continue monitoring local forecasts and air quality advisories from state environmental agencies.
What is causing poor air quality in the affected locations?
The primary cause of poor air quality across these regions is elevated ground-level ozone formation.
Several atmospheric conditions are contributing to ozone accumulation:
- Strong sunshine that accelerates ozone-producing chemical reactions
- High pressure systems creating stagnant air conditions
- Light winds that limit pollutant dispersion
- Existing emissions from vehicles, industrial activities, and other pollution sources
- Warm temperatures that enhance ozone formation
In South Carolina, officials specifically cited dominant high pressure, minimal cloud cover, low atmospheric moisture, light winds, and poor pollutant dispersion as key factors contributing to elevated ozone levels.
How can I protect myself from poor air quality?
- Get a free air quality app for real-time air quality alerts and forecasts.
- Shut doors and windows and set the HVAC to recirculate mode.
- Contribute to your community’s outdoor air quality data.
- Stay indoors when air quality is poor; if you do need to go outdoors, wear a KN95/FFP2 mask.
- Run a high-performance air purifier to filter particles, gases, and other pollutants.
