Portland, Oregon, United States Historical Air Quality Analysis
Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!
August Air Quality Analysis
Portland, Oregon, United States
AQI Trends: Highest and Lowest
Same Day Analysis (31st August ):
On this day, AQI across the 4 years varied significantly: 2025 ranks 1st highest AQI at 40 of Good air quality on the same day.
Download 2024 Annual Data
World Air Quality Report
2025 Days Vs Air Quality
Portland, Oregon, United States
94%
200
6%
12
Total number of days with different AQI categories in last 213 days in 2025 (152 days remaining)
Under WHO’s Safe Air Quality Limits: 94%
Health Risk Level:
Very Low
In 2025, 94% of 213 days were within WHO’s safe air quality limits. The risk of health issues is Very Low, but health impacts are still unclear.
Annual Air Quality Insights
Portland, Oregon, United States
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
30AQI
23AQI
25AQI
24AQI
22AQI
22AQI
25AQI
31AQI
32AQI
35AQI
21AQI
29AQI
40AQI
49AQI
50AQI
49AQI
47AQI
32AQI
48AQI
38AQI
55AQI
55AQI
53AQI
44AQI
37AQI
33AQI
36AQI
47AQI
55AQI
73AQI
38AQI
21AQI
25AQI
25AQI
36AQI
33AQI
28AQI
30AQI
27AQI
46AQI
32AQI
25AQI
24AQI
23AQI
28AQI
36AQI
23AQI
20AQI
21AQI
20AQI
21AQI
22AQI
23AQI
18AQI
22AQI
21AQI
26AQI
23AQI
35AQI
36AQI
23AQI
24AQI
34AQI
51AQI
70AQI
66AQI
72AQI
71AQI
60AQI
57AQI
44AQI
36AQI
34AQI
29AQI
27AQI
25AQI
22AQI
21AQI
18AQI
18AQI
21AQI
21AQI
20AQI
24AQI
20AQI
17AQI
17AQI
17AQI
22AQI
17AQI
22AQI
18AQI
22AQI
26AQI
20AQI
30AQI
16AQI
15AQI
17AQI
20AQI
18AQI
17AQI
20AQI
20AQI
22AQI
23AQI
21AQI
23AQI
22AQI
18AQI
16AQI
17AQI
21AQI
28AQI
35AQI
27AQI
22AQI
15AQI
17AQI
19AQI
28AQI
25AQI
14AQI
16AQI
18AQI
22AQI
22AQI
19AQI
24AQI
24AQI
15AQI
19AQI
18AQI
21AQI
19AQI
21AQI
18AQI
15AQI
17AQI
12AQI
15AQI
21AQI
17AQI
18AQI
18AQI
15AQI
18AQI
22AQI
16AQI
19AQI
19AQI
17AQI
21AQI
23AQI
16AQI
17AQI
20AQI
20AQI
32AQI
32AQI
32AQI
34AQI
30AQI
21AQI
20AQI
22AQI
24AQI
20AQI
15AQI
16AQI
17AQI
17AQI
16AQI
23AQI
30AQI
30AQI
20AQI
16AQI
15AQI
19AQI
22AQI
20AQI
15AQI
15AQI
17AQI
21AQI
18AQI
19AQI
22AQI
16AQI
15AQI
19AQI
19AQI
21AQI
16AQI
21AQI
23AQI
31AQI
31AQI
22AQI
21AQI
22AQI
24AQI
22AQI
21AQI
18AQI
17AQI
22AQI
22AQI
20AQI
23AQI
21AQI
39AQI
26AQI
33AQI
21AQI
19AQI
22AQI
20AQI
No. of days
202526AQI
Highest AQI recorded in
January39AQI
Lowest AQI recorded in
May19AQI
202423AQI
Highest AQI recorded in
November32AQI
Lowest AQI recorded in
May16AQI
202324AQI
Highest AQI recorded in
February32AQI
Lowest AQI recorded in
June19AQI
202229AQI
Highest AQI recorded in
October55AQI
Lowest AQI recorded in
May15AQI
202131AQI
Highest AQI recorded in
January67AQI
Lowest AQI recorded in
May18AQI
202037AQI
Highest AQI recorded in
September112AQI
Lowest AQI recorded in
June17AQI
Most & Least Polluted Years Over the Last 6 Years
Portland's annual 2025 AQI (26) shows an average percentage change of -7.3% (improved AQI) compared to previous years: 2020 (37), 2021 (31), 2022 (29), 2023 (24), 2024 (23).
