Phoenix Air Quality in Winter
Across 2019–2025, Phoenix's winter (December–February) air quality had a median AQI of 76 (Moderate) over 632 monitored days in the Phoenix-Mesa-Scottsdale, AZ area. 25.8% of winter days (163 of 632) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 52.4% of days. The cleanest winter on record here was 2019 (median AQI 61, 1 day above 100) and the worst was 2021 (median 103, 51 days above 100, peak AQI 297).
- Good: 8.2%
- Moderate: 66.0%
- Unhealthy for Sensitive Groups: 17.7%
- Unhealthy or worse: 8.1%
Extra Protection for Phoenix Homes
Air quality in Phoenix is moderate (AQI 51), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
Recommended: Coway AP-1512HH Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
As an Amazon Associate, we earn from qualifying purchases.
How is the air in Phoenix in winter?
Moderate on a typical day: median AQI 76 across 2019–2025, with 25.8% of winter days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓8.2% of winter days were Good (AQI 0–50), 66.0% Moderate (51–100).
- ✓163 days of 632 reached AQI 101+; the winter peak was 1215.
- ✓Cleanest month: February; worst month: January.
Frequently asked questions
What is the air quality like in Phoenix in winter?▾
Across 2019–2025, the median daily AQI in Phoenix in winter was 76 (Moderate). 8.2% of days were Good, 66.0% Moderate, and 25.8% reached Unhealthy for Sensitive Groups or worse, based on 632 monitored days in EPA's Air Quality System.
Is winter a good time for outdoor exercise in Phoenix?▾
A typical winter day in Phoenix is Moderate (median AQI 76): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 4 of winter days (25.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Phoenix's winter air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 52.4% of winter days in Phoenix. The highest winter AQI recorded in 2019–2025 was 1215 (Hazardous), in 2021.
Phoenix winter air quality, year by year
Phoenix winter air quality by year (Phoenix-Mesa-Scottsdale, AZ, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 90 | 61 | 1 | 133 | PM2.5 |
| 2020 | 91 | 97 | 44 | 224 | PM2.5 |
| 2021worst | 90 | 103 | 51 | 297 | O3 |
| 2022 | 90 | 88 | 36 | 189 | PM2.5 |
| 2023 | 90 | 68 | 6 | 179 | PM2.5 |
| 2024 | 91 | 70 | 16 | 261 | PM2.5 |
| 2025 | 90 | 79 | 9 | 1215 | PM10 |
What winter air means in Phoenix
A typical winter day in Phoenix is Moderate (median AQI 76): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 4 of winter days (25.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Winter's median AQI of 76 is in line with Phoenix's whole-year median of 79, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Winter AQI across every EPA metro area (278,620 metro-days, 2019–2025) is 40, so Phoenix runs above the national Winter norm; 25.8% of its Winter days topped AQI 100 versus 0.6% nationally (above average).
Within the season, February is the cleanest month (median AQI 64, 15.2% of days above 100) and January the worst (median 81, 36.0% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Phoenix
The latest EPA AirNow observation puts Phoenix's AQI at 51 (PM2.5). The figures above are multi-year season 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.