Portland, OR Air Quality in July
Across 2019–2025, Portland's July air quality had a median AQI of 39 (Good) over 217 monitored days in the Portland-Vancouver-Hillsboro, OR-WA area. 1.8% of July days (4 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 79.7% of days. The cleanest July on record here was 2019 (median AQI 36, 0 days above 100) and the worst was 2024 (median 43, 2 days above 100, peak AQI 119).
- Good: 80.2%
- Moderate: 18.0%
- Unhealthy for Sensitive Groups: 1.8%
- Unhealthy or worse: 0.0%
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How is the air in Portland in July?
Good on a typical day: median AQI 39 across 2019–2025, with 1.8% of July days above AQI 100. Ground-level ozone is the main driver.
- ✓80.2% of July days were Good (AQI 0–50), 18.0% Moderate (51–100).
- ✓4 days of 217 reached AQI 101+; the July peak was 133.
- ✓Best July: 2019; worst July: 2024.
Frequently asked questions
What is the air quality like in Portland in July?▾
Across 2019–2025, the median daily AQI in Portland in July was 39 (Good). 80.2% of days were Good, 18.0% Moderate, and 1.8% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is July a good time for outdoor exercise in Portland?▾
A typical July day in Portland sits in the Good range (median AQI 39), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 56 of July days (1.8%) reached AQI 101+ in 2019–2025.
Which pollutant causes Portland's July air quality problems?▾
Ground-level ozone set the daily AQI on 79.7% of July days in Portland. The highest July AQI recorded in 2019–2025 was 133 (Unhealthy for Sensitive Groups), in 2024.
Portland July air quality, year by year
Portland July air quality by year (Portland-Vancouver-Hillsboro, OR-WA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 31 | 36 | 0 | 61 | O3 |
| 2020 | 31 | 37 | 1 | 119 | O3 |
| 2021 | 31 | 38 | 0 | 87 | O3 |
| 2022 | 31 | 40 | 1 | 133 | O3 |
| 2023 | 31 | 42 | 0 | 93 | O3 |
| 2024worst | 31 | 43 | 2 | 119 | O3 |
| 2025 | 31 | 39 | 0 | 61 | O3 |
What July air means in Portland
A typical July day in Portland sits in the Good range (median AQI 39), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 56 of July days (1.8%) reached AQI 101+ in 2019–2025.
July's median AQI of 39 is in line with Portland's whole-year median of 41, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median July AQI across every EPA metro area (103,858 metro-days, 2019–2025) is 47, so Portland runs below the national July norm; 1.8% of its July days topped AQI 100 versus 3.6% nationally (below average).
July is part of Portland's summer season (June, July, August); the summer page pools all three months.
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 month 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.