Chicago, Illinois, 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
Chicago, Illinois, United States
AQI Trends: Highest and Lowest
Same Day Analysis (12th August ):
On this day, AQI across the 1 years varied significantly: 2025 ranks 1st highest AQI at 43 of Good air quality on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 12th Aug - 13th Aug 2025
Chicago, Illinois, United States
5 AM12th Aug 2025
8 PM
4 AM13th Aug 2025
52AQI
38AQI
38AQI
32AQI
In the last 24 hours,
Chicago's AQI reached its highest point of 52 at 3 PM during the Day, while the lowest point, 32, was recorded at 3 AM during the Night between 12th Aug and 13th Aug 2025.
Day & Night AQI Trend : Jul - Aug 2025
Chicago, Illinois, United States
25°C18/32°C
26°C20/32°C
28°C23/32°C
21°C19/22°C
23°C18/28°C
25°C21/29°C
22°C21/22°C
23°C19/27°C
26°C21/32°C
27°C22/34°C
29°C25/35°C
25°C23/28°C
26°C23/30°C
27°C23/32°C
27°C24/32°C
28°C23/35°C
24°C23/25°C
23°C20/26°C
22°C20/24°C
23°C18/27°C
23°C19/27°C
22°C20/26°C
23°C20/26°C
25°C21/31°C
27°C22/32°C
29°C23/33°C
29°C23/34°C
29°C25/33°C
26°C23/32°C
29°C24/35°C
--°C/°C
58AQI
58AQI
58AQI
58AQI
2025 Days Vs Air Quality
Chicago, Illinois, United States
72%
120
28%
46
0.6%
1
Total number of days with different AQI categories in last 225 days in 2025 (140 days remaining)
Under WHO’s Safe Air Quality Limits: 72%
Health Risk Level:
Low
In 2025, 72% of 225 days were within WHO’s safe air quality limits. The risk of health issues is Low, but the long-term effects, especially on vulnerable individuals, remain uncertain.
Annual Air Quality Insights
Chicago, Illinois, United States
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
53AQI
28AQI
23AQI
25AQI
37AQI
35AQI
38AQI
21AQI
23AQI
33AQI
27AQI
28AQI
33AQI
24AQI
36AQI
53AQI
75AQI
53AQI
26AQI
24AQI
32AQI
29AQI
23AQI
22AQI
23AQI
21AQI
29AQI
38AQI
51AQI
45AQI
36AQI
34AQI
20AQI
21AQI
36AQI
28AQI
29AQI
24AQI
23AQI
25AQI
19AQI
33AQI
48AQI
45AQI
53AQI
44AQI
34AQI
20AQI
22AQI
35AQI
49AQI
42AQI
40AQI
22AQI
31AQI
31AQI
52AQI
28AQI
19AQI
27AQI
35AQI
36AQI
21AQI
30AQI
28AQI
17AQI
17AQI
22AQI
38AQI
40AQI
18AQI
23AQI
32AQI
23AQI
37AQI
34AQI
33AQI
45AQI
37AQI
22AQI
20AQI
19AQI
25AQI
21AQI
15AQI
20AQI
18AQI
16AQI
22AQI
26AQI
31AQI
41AQI
46AQI
39AQI
36AQI
42AQI
57AQI
58AQI
98AQI
85AQI
81AQI
78AQI
71AQI
61AQI
72AQI
80AQI
76AQI
63AQI
50AQI
55AQI
49AQI
37AQI
31AQI
43AQI
42AQI
46AQI
56AQI
47AQI
34AQI
47AQI
38AQI
24AQI
36AQI
33AQI
33AQI
54AQI
54AQI
57AQI
73AQI
54AQI
53AQI
67AQI
52AQI
45AQI
45AQI
31AQI
57AQI
72AQI
80AQI
51AQI
27AQI
29AQI
37AQI
29AQI
68AQI
78AQI
63AQI
56AQI
34AQI
37AQI
33AQI
43AQI
46AQI
47AQI
103AQI
89AQI
73AQI
79AQI
85AQI
87AQI
93AQI
69AQI
56AQI
53AQI
48AQI
46AQI
43AQI
41AQI
33AQI
32AQI
28AQI
54AQI
52AQI
68AQI
No. of days
202542AQI
Highest AQI recorded in
August68AQI
Lowest AQI recorded in
May28AQI
Most & Least Polluted Years Over the Last 1 Years
Chicago's annual 2025 AQI (42) shows an average percentage change of NaN% (improved AQI) compared to previous years: .