Cheongju, Chungbuk, South Korea Historical Air Quality Analysis
Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!
September Air Quality Analysis
Cheongju, Chungbuk, South Korea
AQI Trends: Highest and Lowest
Same Day Analysis (20th September ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 4th highest AQI at 31 of Good air quality, showing improvement over 2023, 2022 and 2021 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 21st Sep - 22nd Sep 2025
Cheongju, Chungbuk, South Korea
6 AM21st Sep 2025
6 PM
5 AM22nd Sep 2025
AQI
AQI
35AQI
15AQI
In the last 24 hours,
Cheongju's AQI reached its highest point of 35 at 3 AM during the Night, while the lowest point, undefined, was recorded at 5 AM during the Night between 21st Sep and 22nd Sep 2025.
Day & Night AQI Trend : Aug - Sep 2025
Cheongju, Chungbuk, South Korea
27°C22/33°C
28°C24/34°C
27°C23/33°C
25°C22/29°C
25°C20/31°C
26°C21/32°C
26°C22/32°C
26°C22/32°C
27°C22/33°C
26°C22/32°C
24°C21/29°C
25°C19/32°C
22°C21/25°C
26°C20/33°C
26°C21/32°C
24°C20/28°C
22°C17/27°C
20°C19/23°C
22°C19/28°C
23°C17/30°C
21°C19/24°C
24°C20/28°C
23°C19/28°C
24°C19/30°C
24°C20/29°C
22°C20/24°C
19°C17/23°C
17°C16/19°C
17°C15/22°C
--°C/°C
--°C/°C
44AQI
37AQI
45AQI
38AQI
2025 Days Vs Air Quality
Cheongju, Chungbuk, South Korea
41%
108
55%
145
4%
10
Total number of days with different AQI categories in last 264 days in 2025 (101 days remaining)
Under WHO’s Safe Air Quality Limits: 41%
Health Risk Level:
Significant
In 2025, 41% of 264 days were within WHO’s safe air quality limits, and 59% exceeded them. The risk of health issues is Significant, especially for those with existing respiratory or heart conditions.
Annual Air Quality Insights
Cheongju, Chungbuk, South Korea
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
71AQI
73AQI
60AQI
61AQI
66AQI
92AQI
60AQI
72AQI
43AQI
62AQI
63AQI
84AQI
89AQI
93AQI
61AQI
71AQI
95AQI
96AQI
96AQI
115AQI
141AQI
140AQI
127AQI
122AQI
87AQI
63AQI
69AQI
56AQI
63AQI
59AQI
82AQI
92AQI
91AQI
65AQI
57AQI
51AQI
53AQI
51AQI
48AQI
58AQI
61AQI
83AQI
82AQI
54AQI
80AQI
60AQI
103AQI
55AQI
65AQI
51AQI
57AQI
56AQI
60AQI
59AQI
57AQI
57AQI
75AQI
64AQI
78AQI
105AQI
82AQI
58AQI
48AQI
43AQI
70AQI
83AQI
79AQI
88AQI
89AQI
102AQI
93AQI
95AQI
81AQI
52AQI
68AQI
60AQI
72AQI
76AQI
86AQI
90AQI
98AQI
99AQI
101AQI
124AQI
81AQI
89AQI
69AQI
50AQI
49AQI
57AQI
71AQI
71AQI
77AQI
80AQI
65AQI
65AQI
63AQI
73AQI
64AQI
73AQI
76AQI
61AQI
58AQI
43AQI
52AQI
60AQI
63AQI
77AQI
52AQI
58AQI
40AQI
40AQI
31AQI
56AQI
56AQI
48AQI
40AQI
49AQI
59AQI
54AQI
47AQI
50AQI
48AQI
44AQI
46AQI
41AQI
50AQI
67AQI
45AQI
45AQI
63AQI
65AQI
68AQI
70AQI
52AQI
47AQI
44AQI
57AQI
57AQI
40AQI
41AQI
51AQI
55AQI
45AQI
43AQI
56AQI
65AQI
73AQI
74AQI
59AQI
69AQI
80AQI
94AQI
79AQI
57AQI
52AQI
58AQI
63AQI
61AQI
59AQI
58AQI
51AQI
52AQI
60AQI
39AQI
48AQI
54AQI
60AQI
62AQI
62AQI
45AQI
40AQI
34AQI
47AQI
43AQI
34AQI
45AQI
60AQI
59AQI
46AQI
42AQI
40AQI
37AQI
50AQI
49AQI
45AQI
49AQI
57AQI
57AQI
50AQI
46AQI
47AQI
46AQI
58AQI
53AQI
40AQI
49AQI
38AQI
38AQI
30AQI
37AQI
39AQI
34AQI
46AQI
54AQI
49AQI
42AQI
37AQI
50AQI
52AQI
49AQI
51AQI
56AQI
62AQI
60AQI
49AQI
49AQI
45AQI
49AQI
49AQI
53AQI
45AQI
52AQI
40AQI
39AQI
37AQI
37AQI
37AQI
39AQI
49AQI
43AQI
45AQI
45AQI
45AQI
48AQI
49AQI
47AQI
42AQI
46AQI
51AQI
45AQI
43AQI
48AQI
38AQI
44AQI
47AQI
40AQI
34AQI
36AQI
38AQI
45AQI
47AQI
45AQI
45AQI
43AQI
36AQI
39AQI
46AQI
42AQI
34AQI
32AQI
31AQI
31AQI
82AQI
65AQI
79AQI
59AQI
54AQI
55AQI
46AQI
47AQI
40AQI
No. of days
202559AQI
Highest AQI recorded in
January82AQI
Lowest AQI recorded in
September40AQI
202458AQI
Highest AQI recorded in
January79AQI
Lowest AQI recorded in
July34AQI
202366AQI
Highest AQI recorded in
February95AQI
Lowest AQI recorded in
September46AQI
202268AQI
Highest AQI recorded in
January87AQI
Lowest AQI recorded in
August29AQI
202167AQI
Highest AQI recorded in
March90AQI
Lowest AQI recorded in
September38AQI
202063AQI
Highest AQI recorded in
December83AQI
Lowest AQI recorded in
July40AQI
Most & Least Polluted Years Over the Last 6 Years
Cheongju's annual 2025 AQI (59) shows an average percentage change of -8.08% (improved AQI) compared to previous years: 2020 (63), 2021 (67), 2022 (68), 2023 (66), 2024 (58).