Riverside, California – High ozone levels have triggered an air quality alert across Southern California, with unhealthy smog set to linger over the Inland Empire, Coachella Valley, and inland Orange County until 8 p.m. Thursday. Residents in cities from Riverside and San Bernardino to Palm Springs and Anaheim are being urged to limit outdoor activity as the region grapples with peak summer pollution.
According to the South Coast Air Quality Management District, ozone concentrations are expected to reach their highest during afternoon and early evening hours. The alert spans San Bernardino and Riverside County valleys, mountain communities like Big Bear and Idyllwild, and major cities including Irvine and Fullerton.
Health officials warn that ozone pollution can trigger serious respiratory issues, especially for sensitive groups such as children, older adults, people with lung conditions, and outdoor workers. Everyone is advised to keep windows closed, run air conditioners or air purifiers, and avoid outdoor exercise when Air Quality Index readings climb to “Unhealthy” levels.
Residents can help by postponing the use of gasoline-powered equipment and delaying trips to the gas station or use of household chemicals until after sunset. If conditions worsen to “Very Unhealthy” or “Hazardous,” all outdoor physical activity should be avoided.
This ozone episode comes as hot, stagnant summer weather traps pollution in the valleys—similar to high smog events seen in previous Julys. More updates will follow if air quality deteriorates or the alert is extended.
