Clark County’s Department of Air Quality has issued a season-long advisory for ozone from April through September 30.

“We have made tremendous progress on improving air quality in the Las Vegas Valley over the years, but ozone pollution is a challenge for us, especially since the federal standard got more stringent,” said Marci Henson, Director of the County’s Department of Air Quality. In Oct. 2015, the U.S. Environmental Protection Agency set a new standard of 71 parts per billion (ppb) for eight-hour concentrations of ozone. Clark County met the previous standard of 75 ppb but that too was challenging for the community.

At ground level, ozone is a key ingredient of urban smog that can build up during the day in the hottest months of the year because of strong sunlight, hot temperatures, gasoline and chemical vapors, and pollutants from automobiles, wildfires and regional transport. Exposure to ozone can irritate your respiratory system and cause coughing, a sore throat, chest pain and shortness of breath even in healthy people, according to the EPA. People who may be most sensitive to ozone include individuals with lung disease such as asthma, emphysema or chronic bronchitis, older adults, children, and active people who exercise or work vigorously outdoors. Officials recommend you consult your physician if you have a medical condition that makes you sensitive to air pollution.


Clark County’s Department of Air Quality monitors air pollution at 16 monitoring sites in the Las Vegas Valley and provides detailed information about air quality on its website pages, You can subscribe to free air quality forecasts via e-mail or text through the EnviroFlash service at DAQ issues advisories and alerts for ozone when monitoring staff determine that ozone pollution levels are either close or in excess of health-based standards for sensitive groups of people. The EPA’s Air Quality Index,, translates air quality data into colors to help people know when they may experience health effects from air pollution. An AQI of 101 or more is considered a level that may be unhealthy for sensitive groups of people. The following tips help to limit exposure to ozone and reduce its formation at ground level:


  • Reduce the time you are active outdoors when ozone levels are elevated, especially if you are engaged in a strenuous activity or have a respiratory disease.
  • Schedule activities for the morning or evening when ozone levels are usually lower.
  • Substitute a less intense activity – walk instead of jog, for example.
  • Reduce driving – combine errands into one trip.
      • Don’t idle your car engine unnecessarily.
      • Use mass transit or carpool.
      • Fill up your gas tank after sunset. Try not to spill gasoline when filling up, and don’t top off your tank.

  • Keep your car well maintained.
    • Consider landscaping that uses less water and gas-powered equipment to maintain.
    • Turn off lights and electronics when not in use. Less fuel burned at power plants means cleaner air.