New York (WRGB) — An Air Quality Health Advisory has been issued for the New York City Metro region, effective Sunday, August 10, 2025, due to elevated ozone levels, according to a release from New York State Department of Environmental Conservation (DEC) Commissioner Amanda Lefton and State Department of Health (DOH) Commissioner Dr. James McDonald.
The advisory will be in effect from 11 AM to 11 PM and includes New York City, Rockland, and Westchester counties. The DEC and DOH issue such advisories when pollution levels, either ozone or fine particulate matter (PM2.5), are expected to exceed an Air Quality Index (AQI) value of 100.
Summer heat contributes to the formation of ground-level ozone, a key component of photochemical smog. Automobile exhaust and emissions from out-of-state sources are the primary contributors to this surface pollutant, which should not be confused with the protective ozone layer in the upper atmosphere.
Ozone forms when sunlight chemically reacts with nitrogen oxides (NOx) and volatile organic compounds (VOCs) from automobile exhaust and industrial emissions. Although ozone is a colorless gas, it can produce hazy skies and reduce visibility in high concentrations. Wildfire smoke can further enhance ozone production.
The advisory warns that individuals, particularly those with cardiovascular or respiratory diseases, young children, the elderly, and those engaging in outdoor activities, should limit strenuous outdoor physical activity during peak ozone levels, typically from afternoon to early evening. Symptoms such as shortness of breath, chest pain, or coughing should prompt consultation with a physician.
For more information on ozone and PM2.5, visit the DEC and DOH websites. New Yorkers can also sign up for Air Quality Alerts through DEC Delivers or call the toll-free Air Quality Hotline at 1-800-535-1345 for the latest updates.