Air quality advisory for Portland metro area, Salem, Hermiston and Ontario due to smog

By Garrett Christensen on Tuesday, July 21st, 2026 in Columbia Basin News Eastern/Southeast Oregon News More Top Stories

SALEM — The Oregon Department of Environmental quality has issued an air quality advisory for several urban areas across the state due Smog, including both Hermiston in Umatilla County and Ontario in Malheur County. Residents in impacted areas are urged to limited outdoor time and strenuous activates. See the full update from the DEQ below;

(Press release from the Oregon Department of Environmental Quality)

The Oregon Department of Environmental Quality issued an air quality advisory beginning Tuesday morning, July 21, 2026, for the Portland metro area, Salem, Hermiston and Ontario due to elevated levels of ozone pollution, or smog. DEQ expects the air quality advisory to last until 8 p.m. on Wednesday, July 22, 2026.

**Información en español aquí**

DEQ expects ozone pollution to reach levels that could be unhealthy for sensitive groups, including children, pregnant people, older adults and people with heart or respiratory conditions. Health officials recommend sensitive groups limit outdoor activity when pollution levels are high.

DEQ urges residents to protect their health and limit activities that cause pollution during this time. Recommendations include:

Limit driving by using public transit, carpooling or other alternative transportation.
Avoid unnecessary engine idling.
Refuel vehicles during cooler evening hours.
Postpone yard work that uses gas-powered equipment.
Postpone painting and aerosol spray projects.

Smog irritates the eyes, nose and lungs, and contributes to breathing problems. Consult your health care provider if these symptoms worsen.

Ozone forms when hot temperatures and low winds combine with pollution from cars, gas-powered engines and chemicals in paints and aerosols. These air pollutants react with sunlight and heat to produce ozone and haze.

Ozone pollution increases throughout the day with exposure to sunlight, so pollution levels tend to be highest during afternoons and early evenings. Air quality monitors may show good air quality in the morning, then quickly jump to unhealthy levels later in the day.