Highlights
- The West Phoenix station (AQS 040130019) recorded ozone at 72.0 PPB at 2 a.m. Thursday, July 23.
- The reading crossed AirNow's unhealthy-for-sensitive-groups breakpoint for ozone, according to EPA AirNow data reported by Maricopa County Air Quality Department.
- Other pollutants at the same station remained low: CO at 0.1 PPM, NO2 at 3.0 PPB, PM10 at 5.0 UG/M3, and PM2.5 at 0.2 UG/M3.
- Readers can track current conditions and any active advisories on the AirNow Phoenix-area page; Maricopa County Air Quality Department issues High Pollution Advisories via email and text alert.
The West Phoenix air monitoring station recorded ozone at 72.0 PPB at 2 a.m. Thursday, July 23, crossing EPA AirNow's unhealthy-for-sensitive-groups breakpoint for ozone, according to the hourly aggregate published by the EPA AirNow program and reported by the Maricopa County Air Quality Department.
The reading came from AQS site ID 040130019. Other pollutants measured at the same station during the same hour remained well below concern thresholds: carbon monoxide at 0.1 PPM, nitrogen dioxide at 3.0 PPB, PM10 at 5.0 UG/M3, and PM2.5 at 0.2 UG/M3.
For current conditions, forecast, and any active advisories, the AirNow Phoenix-area page is the authoritative source. Maricopa County Air Quality Department also operates a sign-up system for email and text alerts when a High Pollution Advisory is issued or when dust pollution levels rise at selected monitoring locations.
Sources
Every factual claim in this article traces to one of the sources below. See how we work for the editorial process.
- 040130019 retrieved 23/07/2026 03:17
- Maricopa County retrieved 23/07/2026 03:17
Authored by The Scottsdale Signal. Drafted by AI from primary-source material under our beat-specific editorial guides; reviewed by humans before publish under our five-gate process. Sources retrieved at 23/07/2026 03:17. Every claim traces to a source.
