Joliet, Illinois, United States Historical Air Quality Analysis
Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!
October Air Quality Analysis
Joliet, Illinois, United States
AQI Trends: Highest and Lowest
Same Day Analysis (17th October ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 2nd highest AQI at 32 of Good air quality, showing improvement over 2023 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 17th Oct - 18th Oct 2025
Joliet, Illinois, United States
6 AM17th Oct 2025
6 PM
5 AM18th Oct 2025
38AQI
19AQI
48AQI
28AQI
In the last 24 hours,
Joliet's AQI reached its highest point of 48 at 5 AM during the Night, while the lowest point, 19, was recorded at 8 AM during the Day between 17th Oct and 18th Oct 2025.
Day & Night AQI Trend : Sep - Oct 2025
Joliet, Illinois, United States
21°C12/32°C
23°C15/31°C
22°C18/28°C
23°C18/30°C
22°C18/29°C
22°C17/30°C
20°C16/24°C
19°C13/26°C
21°C12/31°C
23°C14/34°C
22°C14/32°C
24°C15/34°C
22°C16/32°C
22°C15/30°C
22°C14/32°C
24°C17/34°C
24°C17/33°C
24°C16/32°C
24°C18/30°C
17°C12/19°C
13°C9/18°C
13°C6/21°C
15°C8/21°C
15°C12/21°C
15°C8/23°C
17°C12/25°C
17°C14/22°C
16°C13/19°C
18°C13/23°C
20°C13/28°C
--°C/°C
40AQI
37AQI
47AQI
39AQI
2025 Days Vs Air Quality
Joliet, Illinois, United States
79%
229
20%
59
0.6%
2
Total number of days with different AQI categories in last 291 days in 2025 (74 days remaining)
Under WHO’s Safe Air Quality Limits: 79%
Health Risk Level:
Low
In 2025, 79% of 291 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
Joliet, Illinois, United States
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
22AQI
24AQI
24AQI
21AQI
21AQI
18AQI
22AQI
25AQI
45AQI
66AQI
38AQI
41AQI
20AQI
25AQI
38AQI
38AQI
30AQI
22AQI
19AQI
19AQI
21AQI
24AQI
29AQI
33AQI
27AQI
20AQI
22AQI
22AQI
21AQI
34AQI
37AQI
20AQI
46AQI
45AQI
20AQI
27AQI
29AQI
23AQI
31AQI
31AQI
28AQI
35AQI
43AQI
31AQI
37AQI
46AQI
28AQI
22AQI
22AQI
22AQI
24AQI
33AQI
36AQI
53AQI
42AQI
36AQI
42AQI
40AQI
24AQI
24AQI
27AQI
34AQI
32AQI
25AQI
24AQI
31AQI
33AQI
25AQI
30AQI
28AQI
36AQI
50AQI
49AQI
71AQI
21AQI
22AQI
25AQI
29AQI
17AQI
22AQI
21AQI
25AQI
19AQI
23AQI
44AQI
48AQI
41AQI
40AQI
30AQI
18AQI
23AQI
35AQI
27AQI
35AQI
24AQI
23AQI
26AQI
18AQI
32AQI
50AQI
49AQI
50AQI
38AQI
35AQI
20AQI
27AQI
39AQI
52AQI
44AQI
41AQI
20AQI
30AQI
28AQI
42AQI
33AQI
20AQI
31AQI
36AQI
33AQI
23AQI
31AQI
38AQI
17AQI
17AQI
29AQI
39AQI
36AQI
20AQI
24AQI
36AQI
27AQI
36AQI
34AQI
42AQI
51AQI
38AQI
23AQI
23AQI
19AQI
27AQI
28AQI
15AQI
21AQI
19AQI
18AQI
23AQI
27AQI
33AQI
41AQI
45AQI
44AQI
42AQI
41AQI
57AQI
50AQI
86AQI
77AQI
84AQI
75AQI
71AQI
61AQI
71AQI
81AQI
79AQI
69AQI
55AQI
55AQI
44AQI
31AQI
28AQI
43AQI
43AQI
47AQI
58AQI
54AQI
39AQI
49AQI
45AQI
26AQI
39AQI
32AQI
32AQI
53AQI
53AQI
56AQI
66AQI
53AQI
54AQI
69AQI
48AQI
51AQI
40AQI
28AQI
57AQI
75AQI
79AQI
48AQI
30AQI
28AQI
33AQI
27AQI
62AQI
77AQI
64AQI
56AQI
33AQI
26AQI
29AQI
34AQI
40AQI
46AQI
114AQI
110AQI
86AQI
81AQI
78AQI
76AQI
87AQI
59AQI
56AQI
55AQI
49AQI
48AQI
41AQI
48AQI
62AQI
73AQI
54AQI
38AQI
36AQI
24AQI
20AQI
19AQI
30AQI
31AQI
22AQI
18AQI
25AQI
35AQI
31AQI
23AQI
26AQI
36AQI
39AQI
39AQI
43AQI
51AQI
44AQI
20AQI
26AQI
33AQI
30AQI
44AQI
52AQI
49AQI
55AQI
59AQI
54AQI
53AQI
54AQI
57AQI
56AQI
53AQI
50AQI
36AQI
41AQI
22AQI
26AQI
36AQI
37AQI
42AQI
39AQI
46AQI
42AQI
38AQI
59AQI
61AQI
50AQI
32AQI
28AQI
36AQI
21AQI
33AQI
35AQI
25AQI
43AQI
56AQI
33AQI
35AQI
32AQI
28AQI
33AQI
31AQI
33AQI
30AQI
54AQI
50AQI
48AQI
43AQI
39AQI
No. of days
202539AQI
Highest AQI recorded in
June54AQI
Lowest AQI recorded in
January28AQI
202432AQI
Highest AQI recorded in
July38AQI
Lowest AQI recorded in
April23AQI
202342AQI
Highest AQI recorded in
June79AQI
Lowest AQI recorded in
December33AQI
202237AQI
Highest AQI recorded in
November42AQI
Lowest AQI recorded in
April30AQI
202140AQI
Highest AQI recorded in
July48AQI
Lowest AQI recorded in
September31AQI
202038AQI
Highest AQI recorded in
December44AQI
Lowest AQI recorded in
May32AQI
Most & Least Polluted Years Over the Last 6 Years
Joliet's annual 2025 AQI (39) shows an average percentage change of 3.6% (worsened AQI) compared to previous years: 2020 (38), 2021 (40), 2022 (37), 2023 (42), 2024 (32).