Phoenix Air Quality in August
Across 2019–2025, Phoenix's August air quality had a median AQI of 101 (Unhealthy for Sensitive Groups) over 217 monitored days in the Phoenix-Mesa-Scottsdale, AZ area. 50.7% of August days (110 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 76.5% of days. The cleanest August on record here was 2025 (median AQI 89, 10 days above 100) and the worst was 2020 (median 213, 30 days above 100, peak AQI 1194).
- Good: 2.8%
- Moderate: 46.5%
- Unhealthy for Sensitive Groups: 32.7%
- Unhealthy or worse: 18.0%
Reduce Indoor Ozone in Phoenix
Today's main pollutant in Phoenix is ground-level ozone (AQI 47). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Phoenix in August?
Unhealthy for Sensitive Groups on a typical day: median AQI 101 across 2019–2025, with 50.7% of August days above AQI 100. Ground-level ozone is the main driver.
- ✓2.8% of August days were Good (AQI 0–50), 46.5% Moderate (51–100).
- ✓110 days of 217 reached AQI 101+; the August peak was 1194.
- ✓Best August: 2025; worst August: 2020.
Frequently asked questions
What is the air quality like in Phoenix in August?▾
Across 2019–2025, the median daily AQI in Phoenix in August was 101 (Unhealthy for Sensitive Groups). 2.8% of days were Good, 46.5% Moderate, and 50.7% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is August a good time for outdoor exercise in Phoenix?▾
A typical August day in Phoenix is already Unhealthy for Sensitive Groups (median AQI 101): people with asthma or heart disease, children and older adults should reduce prolonged outdoor exertion on most days, and about 51% of August days (50.7%) were at that level or worse.
Which pollutant causes Phoenix's August air quality problems?▾
Ground-level ozone set the daily AQI on 76.5% of August days in Phoenix. The highest August AQI recorded in 2019–2025 was 1194 (Hazardous), in 2020.
Phoenix August air quality, year by year
Phoenix August air quality by year (Phoenix-Mesa-Scottsdale, AZ, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 90 | 10 | 244 | O3 |
| 2020worst | 31 | 213 | 30 | 1194 | O3 |
| 2021 | 31 | 100 | 15 | 182 | O3 |
| 2022 | 31 | 108 | 20 | 689 | O3 |
| 2023 | 31 | 87 | 14 | 251 | O3 |
| 2024 | 31 | 87 | 11 | 150 | O3 |
| 2025cleanest | 31 | 89 | 10 | 647 | O3 |
What August air means in Phoenix
A typical August day in Phoenix is already Unhealthy for Sensitive Groups (median AQI 101): people with asthma or heart disease, children and older adults should reduce prolonged outdoor exertion on most days, and about 51% of August days (50.7%) were at that level or worse.
August's median AQI of 101 is above Phoenix's whole-year median of 79, making it one of the area's dirtier periods. Nationally, the median August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so Phoenix runs above the national August norm; 50.7% of its August days topped AQI 100 versus 3.5% nationally (above average).
August is part of Phoenix's summer season (June, July, August); the summer page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Phoenix
The latest EPA AirNow observation puts Phoenix's AQI at 47 (O3). The figures above are multi-year month statistics, not today's reading.
View current Phoenix air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Phoenix-Mesa-Scottsdale, AZ), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.