Portland, OR Air Quality in 2024
In 2024, Portland's air quality (Portland-Vancouver-Hillsboro, OR-WA area) had a median daily AQI of 38 (Good) across 366 monitored days. 6 days (1.6%) reached Unhealthy for Sensitive Groups or worse, 280 were Good, and the year's peak AQI was 127 (Unhealthy for Sensitive Groups). Ground-level ozone set the daily AQI on 215 of those days. The cleanest month of 2024 was January (median AQI 33, 0 days above 100) and the worst was August (median 44, 2 days above 100, peak 126).
- Good: 76.5%
- Moderate: 21.9%
- Unhealthy for Sensitive Groups: 1.6%
- Unhealthy or worse: 0.0%
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How was Portland's air quality in 2024?
Good on a typical day: median AQI 38, with 6 days above AQI 100 out of 366 monitored — the 4th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2024: 127 (Unhealthy for Sensitive Groups).
- ✓Ground-level ozone was the main pollutant on 215 days.
- ✓Cleanest month: January; worst: August.
Frequently asked questions
What was the average AQI in Portland in 2024?▾
EPA's Air Quality System puts Portland's (Portland-Vancouver-Hillsboro, OR-WA) median daily AQI for 2024 at 38, which is Good. 6 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 127.
Which month had the worst air quality in Portland in 2024?▾
The cleanest month of 2024 was January (median AQI 33, 0 days above 100) and the worst was August (median 44, 2 days above 100, peak 126).
Was 2024 a good or bad year for Portland's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2024 ranks 4th cleanest by days above AQI 100. 2024's median of 38 is below the area's typical annual median of 41.
Portland month by month in 2024
Portland air quality month by month, 2024 (Portland-Vancouver-Hillsboro, OR-WA, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| Januarycleanest | 31 | 33 | 0 | 66 | PM2.5 |
| February | 29 | 34 | 0 | 64 | PM2.5 |
| March | 31 | 38 | 0 | 60 | O3 |
| April | 30 | 38 | 0 | 51 | O3 |
| May | 31 | 39 | 0 | 61 | O3 |
| June | 30 | 37 | 0 | 77 | O3 |
| July | 31 | 43 | 2 | 119 | O3 |
| Augustworst | 31 | 44 | 2 | 126 | O3 |
| September | 30 | 34 | 1 | 120 | O3 |
| October | 31 | 44 | 0 | 68 | PM2.5 |
| November | 30 | 47 | 1 | 127 | PM2.5 |
| December | 31 | 43 | 0 | 77 | PM2.5 |
How 2024 compares
Among the 7 years EPA has published for the area (2019–2025), 2024 ranks 4th cleanest by days above AQI 100.
2024's median of 38 is below the area's typical annual median of 41.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Portland
The latest EPA AirNow observation puts Portland's AQI at 29 (PM2.5). The figures above are multi-year annual statistics, not today's reading.
View current Portland air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Portland-Vancouver-Hillsboro, OR-WA), 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.