May marks the start of summer ozone season in the South Coast Air Basin. Hot, stagnant weather during this time of year can increase the formation of ground-level ozone—also known as smog, leading to unhealthy air quality throughout the region. As hotter temperatures return, South Coast AQMD reminds residents to stay informed of air quality levels in their area and adjust their outdoor activities accordingly.

During smog season, weather extremes such as dust storms and wildfires can also lead to poor air quality, which can cause or worsen breathing problems, asthma attacks, lung inflammation and bronchitis. Sensitive groups such as young children, older adults, pregnant women, and people with lung or heart issues are at higher risk of having health problems from air pollution. Poor air quality cannot always be seen with the naked eye; tracking air quality levels on the South Coast AQMD Mobile App or on South Coast AQMD’s website at www.aqmd.gov/aqimap can help protect your health by indicating when precautions are recommended.

In July, higher levels of particulate matter can sometimes be expected across the South Coast Air Basin following Independence Day celebrations. Fireworks are known to emit high levels of PM2.5 and coarse particulate matter (PM10) as well as metal air pollutants, all of which can contribute to negative health effects. Each year, air quality on July 4th and July 5th varies depending on the amount of pollution from fireworks and weather conditions. Residents can help keep their air clean by refraining from using personal fireworks.

Smog season officially ends on September 30, although high ozone levels may continue well into the fall and other air pollutants can lead to unhealthy air quality during the rest of the year.

Visit www.aqmd.gov/advisory for current air quality advisories during extreme air quality events such as wildfires or dust storms and sign up to receive alerts via email at www.airalerts.org.