Air Quality Division: Assessment: Forecasting and High Pollution Advisories

ADEQ's Air Quality Forecasting program provides air quality forecasts for several areas throughout Arizona. ADEQ forecasters issue the following forecast products six days a week (Sunday – Friday).

To receive email or text notification of these forecasts, sign up for Daily Air Alerts.

Health Watches and High Pollution Advisories may be issued in conjunction with Ensemble forecast products. These watches or advisories indicate that either air quality is poor or may become poor during the forecast period. These notices are based on the U.S. EPA Air Quality Index (AQI) , which classifies pollution levels with respect to their potential health impacts (e.g., moderate, unhealthy), and health concerns associated with each classification.

ADEQ issues a Health Watch when the highest concentrations of ozone or particulate matter (PM) levels may approach the federal health standard. If a Health Watch is issued, people are encouraged to make voluntary efforts to limit activities that cause air pollution. People who are sensitive to air pollution (e.g. those with heart or lung disease, children, and the elderly) are advised to limit their outdoor activity.

A High Pollution Advisory (HPA) is issued when the highest concentrations of ozone or PM levels may exceed the federal health standard. High Pollution Advisories encourage people to limit outdoor activities, reduce driving, and other activities that cause air pollution. A High Pollution Advisory may also alert businesses to implement their travel reduction plans. Depending on the severity of the HPA, a larger portion of the population may begin to experience health effects. The ensemble forecast will provide additional details on the expected severity of the HPA as determined by the forecasts AQI.

The following activities are illegal in Area A, which includes portions of Maricopa and Pinal Counties during days when HPAs have been called for particulate matter:

  • Use of an off-highway vehicle (including an all-terrain vehicle or an off-road recreation motor vehicle) on an unpaved surface that is not a public or private road, street, or easement - except at designated locations and events where dust controls are in place.
  • City, Town, and County employees and contractors are prohibited from operating leaf blowers, except in vacuum mode, on days when a high pollution advisory has been issued. Residents and private contractors within the area are discouraged from using blowers on HPA days as well.
  • Residential wood burning, except in U.S. Environmental Protection Agency-approved woodstoves and fireplace inserts or if it is the sole source of heat.
  • Recreational outdoor fires except fires used for cooking food or providing warmth for human beings.

ADEQ air quality meteorologists provide forecasts for Maricopa County, Sunday-Friday, that include air quality public health information statements. Additionally, the forecast can be heard on the ADEQ hotline at (602) 771-2367 or (800) 234-5677.

Pima County provides forecasts and issues advisories in the Tucson area. Pinal County's Department of Environmental Quality provides air quality information for Pinal County.

Valley Metro provides email notices for high pollution advisories, and other news and information related to transit options in the valley. You can receive these messages by subscribing to Valley Metro Email Notices . Valley Metro's Rideshare program is now Share the Ride which is a matching system allowing commuters to find carpooling partners or bus and light rail options.

ADEQ retains statistical information regarding past forecasts and generates a forecast report for each month. These reports for April through September 2003 pertain to Ozone pollution only. Beginning in October 2003 they include information on all four pollutants (ozone, carbon monoxide, PM10 and PM2.5). Daily tables show the maximum concentrations and corresponding Air Quality Index values of each of the four pollutants for each month. These are preliminary data from monitors within or adjacent to the ADEQ forecast area and in the case of ozone, include Yuma.

Additional Information:

For more information, please contact Joe Paul – (602) 771-2363, or Bryan Paris – (602) 771-7665.