EPA ACTIVE WATCH Western US & Intermountain Basins: Wildfire Smoke & Elevated PM2.5 Infiltration
Air Quality Advisory • Published 2026-06-28

Phoenix, AZ: Maricopa County Issues High Pollution Advisory for Ground-Level Ozone

Stagnant atmospheric high pressure combined with triple-digit temperatures resulted in ground-level ozone concentrations reaching 82 ppb across the Phoenix metro basin. Learn what filtration works and how to protect sensitive family members during Phoenix's air quality advisory.

Sponsor
EPA Advisory Summary
Location
Phoenix, AZ
Peak Observed AQI
142 AQI
Pollutant Metric
Moderate particulate, Elevated O3

What Happened in Phoenix

Stagnant atmospheric high pressure combined with triple-digit temperatures resulted in ground-level ozone concentrations reaching 82 ppb across the Phoenix metro basin.

Recommended Protective Measures

Limit outdoor exertion between 1:00 PM and 7:00 PM. Note that mechanical HEPA filters do not capture ozone; activated carbon adsorption is required.

Verified Air Cleaning Technologies That Work

During high PM2.5 or wildfire smoke alerts, ordinary fans or negative ionizers fail to clear indoor air. Independent environmental testing mandates true mechanical capture:

  • True HEPA (H13 or higher): Captures 99.97% of smoke particles down to 0.3 microns.
  • Activated Carbon Pellets: Necessary to adsorb volatile organic compounds (VOCs) and smoke odors that bypass HEPA filters.
  • Sufficient CADR Sizing: Your unit must deliver at least 4 to 5 air changes per hour for your room square footage.

Check the full city profile for historical trends: View Phoenix, AZ Historical Air Quality & Clean Air Score →

Sponsor

Frequently Asked Questions

How severe is the current air quality advisory in Phoenix?

Stagnant atmospheric high pressure combined with triple-digit temperatures resulted in ground-level ozone concentrations reaching 82 ppb across the Phoenix metro basin. Sensitive individuals, children, and seniors should stay indoors and keep windows sealed during elevated pollution hours.

What air filtration is required during this Phoenix event?

Limit outdoor exertion between 1:00 PM and 7:00 PM. Note that mechanical HEPA filters do not capture ozone; activated carbon adsorption is required. Standard cloth masks and simple ionizing purifiers are not effective; rely exclusively on sealed True HEPA (H13) units and active carbon adsorption.

Where does this regulatory air quality data come from?

Official readings originate from Arizona Department of Environmental Quality (ADEQ), cross-referenced with federal EPA AirNow regulatory monitoring stations.