Portland air quality
Oregon, United States · Live AQI and hourly forecast for the next 5 days · updated Sat 5:00 PM local time
Moderate
Acceptable. Unusually sensitive people should ease off long, intense outdoor effort.
- Next 24 hours
- 34–55US AQI, highest around Sat 5:00 PM
- Best time outside
- Sun 2:00 PM–5:00 PMUS AQI about 34
- PM2.5 vs WHO guideline
- 0.4×6.2 µg/m³ over 24 h, guideline 15
- Cigarette equivalent
- ≈ 0.3 a dayBerkeley Earth rule of thumb
- European AQI
- Fairlevel 2 of 6
Loading the live globe…
Pollutants in Portland right now
| Pollutant | Now | Next 24 h vs WHO | US AQI band |
|---|---|---|---|
| Fine particles (PM2.5) | 4.7 µg/m³ | 0.4× | Good |
| Coarse particles (PM10) | 6.6 µg/m³ | 0.2× | Good |
| Nitrogen dioxide (NO2) | 1.9 µg/m³ | 0.3× | Good |
| Ozone (O3) | 78 µg/m³ | 0.7× | Good |
| Sulphur dioxide (SO2) | 1.2 µg/m³ | 0.0× | Good |
| Carbon monoxide (CO) | 123 µg/m³ | 0.0× | Good |
| Desert dust | 0 µg/m³ | ||
| Smoke and haze (aerosol optical depth) | 0.07 | ||
| UV index | 0.7 |
“Next 24 h vs WHO” compares the forecast with the World Health Organization’s 2021 guideline levels: 24-hour means of 15 µg/m³ for PM2.5, 45 for PM10, 25 for NO2, 40 for SO2 and 4 mg/m³ for CO, and 100 µg/m³ over 8 hours for ozone. Above 1× is above the guideline.
Next 48 hours
Hourly US AQI. Highest 55 around Sat 5:00 PM, lowest 34 around Sun 2:00 PM.
5-day air quality forecast for Portland
Daily range of the hourly US AQI, from lowest to highest, on a scale of 0 to 150.
| Day | US AQI | At worst | PM2.5 avg | |
|---|---|---|---|---|
| Sat, Sep 26 | 27–55 | 11 | ||
| Sun, Sep 27 | 34–54 | 6.6 | ||
| Mon, Sep 28 | 37–52 | 10 | ||
| Tue, Sep 29 | 52–57 | 13 | ||
| Wed, Sep 30 | 58–67 | 15 |
Common questions about the air in Portland
Is the air in Portland safe today?
For most people, yes. Right now the US AQI in Portland is 55, which counts as moderate. Acceptable. Unusually sensitive people should ease off long, intense outdoor effort.
When is the best time to be outside in Portland?
Sun 2:00 PM–5:00 PM. That is the cleanest stretch in the next 24 hours, with the US AQI averaging about 34. The worst hour is around Sat 5:00 PM, at 55.
What is the main pollutant in Portland?
Ozone (O3). It drives the index right now, at 78 µg/m³. Formed by sunlight acting on traffic and plant emissions. Highest on hot, still afternoons, often downwind of cities.
How does Portland's air compare with the WHO guideline?
Within the guideline. Over the next 24 hours PM2.5 averages about 6.2 µg/m³, against the World Health Organization's 24-hour guideline of 15 µg/m³. The other pollutants stay within their guideline levels.
How many cigarettes is a day of Portland's air?
About 0.3 cigarettes. Over the next 24 hours PM2.5 averages about 6.2 µg/m³. By Berkeley Earth's rule of thumb, 22 µg/m³ breathed for a day is roughly one cigarette.
Will air quality in Portland improve this week?
Monday looks cleanest. Its AQI peaks at 52, against 67 on Wednesday, the worst day in the forecast.
Measured near Portland
| Station | PM2.5 µg/m³ | Measured |
|---|---|---|
| Portland Lincoln High School AirNow, reference monitor | 2.5 | Sat 4:00 PM |
| Portland Benson High School AirNow, reference monitor | 1.9 | Sat 4:00 PM |
| Unnamed sensor Sensor.Community, low-cost sensor | 117 | Sat 5:38 PM |
Air quality near Portland
- Seattle 234 km N
- Vancouver 420 km N
- Sacramento 777 km S
- San Francisco 861 km S
- Calgary 884 km NE
- Fresno 1,005 km S
About this forecast
Forecast from CAMS global via Open-Meteo: the Copernicus Atmosphere Monitoring Service (CAMS) model at about 40 km resolution (10 km inside Europe), refreshed twice a day. Models smooth out street-level peaks, so busy roads and industrial sites can be worse than shown; ground stations, where there are any nearby, show what monitors actually measure. The US AQI follows the US EPA scale and the European AQI the EEA bands. Readings for 45.52°N, 122.68°W, updated 2026-09-27 00:00 UTC.