Portland air quality now

United States · The summary is refreshed every 15 minutes.

October 22

The air is clean now

Portland

10°C

Clear

9AQI

1012hPa

Atmospheric
pressure

87%

Humidity

Portland, October 21, 2026: daily mean PM2.5 9 µg/m³ (4 sensors), level “Low” — as in the Atmy Data Hub. Now (11:00 local time): 1.7 µg/m³. Open methodology and data in JSON: Methodology and data sources · JSON

Right now in Portland, PM2.5 averages 1.7 µg/m³ — “good” on the US EPA scale (approximate, from hourly readings). Mean of 4 sensors on the Atmy network, readings from 10:47–10:47 local time (17:47–17:47 UTC), summary prepared at 11:00 local time. Median: 1.5 µg/m³; range across sensors: 0.0–3.7 µg/m³.

In Portland the air is good right now (approximate, US EPA scale). From 22:00 to 11:00 local time the city mean PM2.5 fell from 28.3 to 1.7 µg/m³.

The weather data do not point to a clear reason for this level.

Weather now: clear, 10°C, wind 2 m/s, humidity 87%. By 14:00 the wind is expected to pick up to 4 m/s, which may clear the air.

Written automatically at 11:00 local time (18:00 UTC) from sensor measurements and the weather forecast. Values are approximate; hypotheses are marked.

7 km/h

Wind, NW

0 mm

Precipitation today

Portland: air quality for the completed day

Metric: PM2.5, µg/m³ · Color scale: EPA AQI · October 21, 2026 · 00:00–24:00 UTC

9 µg/m³ Low

Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 9 µg/m³ from 4 sensors that passed the quality check — the same value as in the Atmy Data Hub.

No. 1 of 2 cities in United States and No. 131 of 297 worldwide, from the most polluted.

LowModerateElevatedHighVery highExtremely high

Air Quality in United States for the Completed Day

Metric: PM2.5, µg/m³ · Color scale: EPA AQI · October 21, 2026 · 00:00–24:00 UTC

Portland →9 µg/m³Bellevue →9 µg/m³
LowModerateElevatedHighVery highExtremely high

Source: Air monitoring system atmy.ai

Portland: PM2.5 by month

Metric: PM2.5, µg/m³ · Color scale: EPA AQI

Mean
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
This month
6
5
8
5
8
3
2
1
2
1
5
14
18
33

Monthly means of quality-checked sensors, as in the Data Hub trend; the current month is still incomplete, “-” means no data.

Pollution accumulation index now

27%An estimate of weather conditions · not a PM2.5 forecast

Now2736
11.0019.0002.0010.00

Pollution accumulation forecast

Today — October 22

16°/7°

Index by time of day

53/100Moderate

  1. 53/100Night
  2. 43/100Morning
  3. 6/100Day
  4. 24/100Evening

Friday — October 23

14°/5°

Index by time of day

53/100Moderate

  1. 53/100Night
  2. 42/100Morning
  3. 10/100Day
  4. 19/100Evening

Saturday — October 24

16°/6°

Index by time of day

50/100Moderate

  1. 50/100Night
  2. 40/100Morning
  3. 8/100Day
  4. 18/100Evening

Sunday — October 25

18°/10°

Index by time of day

49/100Moderate

  1. 49/100Night
  2. 38/100Morning
  3. 8/100Day
  4. 24/100Evening

Monday — October 26

18°/10°

Index by time of day

56/100Moderate

  1. 56/100Night
  2. 37/100Morning
  3. 7/100Day
  4. 20/100Evening

Tuesday — October 27

12°/10°

Index by time of day

41/100Moderate

  1. 41/100Night
  2. 29/100Morning
  3. 8/100Day
  4. 27/100Evening

Forecast of conditions that trap pollution near the surface

Weather

10°

Clear. Feels like 9°C

  1. MorningClear10°C87%
  2. DayCloudy16°C68%
  3. EveningClear8°C62%

Wind

7km/hWind from the NW

11km/hWind gusts

Wind force: 2

Gusts up to 33 km/h are expected.

10-day weather forecast for Portland

United States

  1. TodayOct 22Cloudy16°C7°C
  2. FriOct 23Cloudy14°C5°C
  3. SatOct 24Cloudy16°C6°C
  4. SunOct 25Cloudy18°C10°C
  5. MonOct 26Rain18°C10°C
  6. TueOct 27Rain12°C10°C
  7. WedOct 28Partly cloudy19°C7°C
  8. ThuOct 29Cloudy19°C10°C
  9. FriOct 30Cloudy16°C9°C
  10. SatOct 31Cloudy14°C9°C

Where in Portland is the air worse?

See all sensors

Highest current reading: 3.7 µg/m³ (Pearl District). Lowest: 0.0 µg/m³ (Clinton Park). The list shows every sensor, highest first.

  1. Pearl District →4 µg/m³
  2. Woodstock →2 µg/m³
  3. Woodstock Neighborhood, Portland, OR →1 µg/m³
  4. Clinton Park →0 µg/m³

Source: atmy.ai monitoring network

Who provides the data

Sensors in the summary by network: AirGradient — 4 sensors.

Atmy shows the networks’ readings after the Data Hub’s quality check: test devices and sensors that fail it are left out.

United States: sensors in total

41

  1. BellevueUnited States

    4

  2. PortlandUnited States

    4

  3. RenoUnited States

    3

Cities with the most sensors

All sensors on the map, by city as the map assigns them; the city’s values count only the sensors that pass the Data Hub’s quality check.

Air quality calendar: Portland

Daily mean PM2.5 of the city sensors, µg/m³

Click a day to see its date and value.

LowModerateElevatedHighVery highExtremely high

Widget for your site

A card with the current PM2.5 in Portland: it is refreshed every 15 minutes and links to this page. Paste the code into your site.

Air quality in Portland now — Atmy

United States · City ranking · All pilot cities

Questions

What was the air quality in Portland over the last completed day?

Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 9 µg/m³ from 4 sensors that passed the quality check — the same value as in the Atmy Data Hub. No. 1 of 2 cities in United States and No. 131 of 297 worldwide, from the most polluted.

What is the air quality in Portland right now?

Right now in Portland, PM2.5 averages 1.7 µg/m³ — “good” on the US EPA scale (approximate, from hourly readings). Mean of 4 sensors on the Atmy network, readings from 10:47–10:47 local time (17:47–17:47 UTC), summary prepared at 11:00 local time. Median: 1.5 µg/m³; range across sensors: 0.0–3.7 µg/m³.

Is it safe to be outdoors in Portland now?

The current level is “good” (US EPA scale, approximate). Air quality is satisfactory; no restrictions are recommended. This is the standard guidance of the scale, not medical advice.

Where in Portland is the air worse?

Highest current reading: 3.7 µg/m³ (Pearl District). Lowest: 0.0 µg/m³ (Clinton Park). The list shows every sensor, highest first.

Where do these data come from?

From Atmy sensors and connected public networks (citizen, experimental and government monitors), aggregated by Atmy. Values are approximate; see the methodology.

How often is this page updated?

The summary is rebuilt every 15 minutes from the latest reading of each sensor, each no older than one hour.

Is the air in Portland polluted?

Over the last 350 days with data, the mean daily PM2.5 in Portland was 6.1 µg/m³ — 1.2 times the WHO annual guideline (5 µg/m³). Over the last 30 days: 18.2 µg/m³. From Atmy's archive of daily city means.

When is the air in Portland cleanest?

In Atmy's daily archive, the cleanest month of the last year was June 2026: 1.0 µg/m³ on average.

When is the air in Portland most polluted?

The most polluted month of the last year was September 2026: 16.4 µg/m³ on average.

Is the air in Portland worse in the heating season?

From November to March the mean daily PM2.5 was 5.2 µg/m³, from June to August 6.5 µg/m³ (last 365 days).

Data

Where do these data come from?

The daily value is the Data Hub’s: the mean of the city’s sensors that passed the nightly quality check, each with at least 12 valid hours, and only with sensors at four places 500 m apart; days are UTC.

“Now” uses the same sensors and rule: the mean of their latest readings, each at most 60 minutes old, shown only with sensors at four places 500 m apart reporting.

Source: public Atmy monitoring data. Methodology and data sources · Data terms