Sliven, Sliven Province, Bulgaria 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
Sliven, Sliven Province, Bulgaria
AQI Trends: Highest and Lowest
Same Day Analysis (4th August ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 2nd highest AQI at 37 of Good air quality, showing improvement over 2024 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 4th Aug - 5th Aug 2025
Sliven, Sliven Province, Bulgaria
5 AM4th Aug 2025
8 PM
4 AM5th Aug 2025
42AQI
33AQI
38AQI
36AQI
In the last 24 hours,
Sliven's AQI reached its highest point of 42 at 12 PM during the Day, while the lowest point, 33, was recorded at 6 AM during the Day between 4th Aug and 5th Aug 2025.
Day & Night AQI Trend : Jul - Aug 2025
Sliven, Sliven Province, Bulgaria
26°C18/35°C
26°C18/36°C
27°C18/37°C
26°C16/37°C
20°C12/28°C
21°C13/28°C
23°C16/31°C
25°C16/34°C
26°C18/35°C
26°C19/34°C
26°C20/32°C
25°C16/34°C
21°C14/29°C
23°C15/31°C
25°C17/33°C
28°C20/37°C
30°C21/39°C
29°C22/39°C
27°C19/37°C
28°C20/38°C
29°C22/38°C
27°C20/35°C
27°C19/36°C
25°C19/35°C
24°C17/31°C
22°C19/28°C
21°C17/27°C
24°C17/32°C
24°C17/33°C
25°C18/33°C
--°C/°C
43AQI
43AQI
44AQI
44AQI
2025 Days Vs Air Quality
Sliven, Sliven Province, Bulgaria
38%
81
63%
135
Total number of days with different AQI categories in last 217 days in 2025 (148 days remaining)
Under WHO’s Safe Air Quality Limits: 38%
Health Risk Level:
High
In 2025, 38% of 217 days were within WHO’s safe air quality limits. The risk of health issues is High, with respiratory problems, heart disease, skin issues, and stress being more common, particularly among children and the elderly.
Annual Air Quality Insights
Sliven, Sliven Province, Bulgaria
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
88AQI
82AQI
79AQI
73AQI
68AQI
67AQI
69AQI
70AQI
70AQI
70AQI
66AQI
62AQI
60AQI
58AQI
58AQI
59AQI
61AQI
66AQI
71AQI
71AQI
73AQI
75AQI
76AQI
77AQI
75AQI
73AQI
72AQI
72AQI
68AQI
69AQI
70AQI
74AQI
72AQI
72AQI
69AQI
67AQI
64AQI
63AQI
62AQI
61AQI
60AQI
61AQI
61AQI
62AQI
62AQI
64AQI
64AQI
62AQI
61AQI
60AQI
60AQI
59AQI
59AQI
59AQI
60AQI
62AQI
67AQI
66AQI
68AQI
68AQI
63AQI
61AQI
60AQI
62AQI
62AQI
61AQI
61AQI
63AQI
63AQI
63AQI
63AQI
61AQI
60AQI
58AQI
56AQI
54AQI
51AQI
48AQI
48AQI
51AQI
53AQI
53AQI
54AQI
56AQI
58AQI
58AQI
58AQI
57AQI
56AQI
56AQI
54AQI
52AQI
52AQI
51AQI
50AQI
46AQI
42AQI
42AQI
42AQI
43AQI
39AQI
36AQI
37AQI
39AQI
40AQI
44AQI
44AQI
42AQI
42AQI
42AQI
41AQI
41AQI
41AQI
42AQI
43AQI
43AQI
41AQI
39AQI
37AQI
37AQI
43AQI
45AQI
62AQI
50AQI
51AQI
53AQI
52AQI
53AQI
57AQI
57AQI
48AQI
54AQI
53AQI
52AQI
53AQI
54AQI
49AQI
53AQI
52AQI
57AQI
53AQI
55AQI
53AQI
52AQI
51AQI
43AQI
42AQI
42AQI
49AQI
46AQI
44AQI
44AQI
44AQI
44AQI
47AQI
51AQI
53AQI
55AQI
54AQI
54AQI
56AQI
57AQI
58AQI
54AQI
53AQI
51AQI
53AQI
55AQI
52AQI
55AQI
55AQI
52AQI
51AQI
50AQI
51AQI
50AQI
51AQI
52AQI
51AQI
49AQI
46AQI
47AQI
44AQI
41AQI
42AQI
46AQI
48AQI
49AQI
50AQI
51AQI
49AQI
49AQI
48AQI
49AQI
48AQI
45AQI
44AQI
45AQI
39AQI
36AQI
35AQI
40AQI
42AQI
41AQI
39AQI
39AQI
42AQI
45AQI
50AQI
49AQI
43AQI
43AQI
43AQI
39AQI
39AQI
37AQI
70AQI
64AQI
58AQI
43AQI
51AQI
52AQI
44AQI
40AQI
No. of days
202554AQI
Highest AQI recorded in
January70AQI
Lowest AQI recorded in
August40AQI
202429AQI
Highest AQI recorded in
December58AQI
Lowest AQI recorded in
July13AQI
202321AQI
Highest AQI recorded in
December32AQI
Lowest AQI recorded in
January7AQI
20229AQI
Highest AQI recorded in
February12AQI
Lowest AQI recorded in
August6AQI
202112AQI
Highest AQI recorded in
February18AQI
Lowest AQI recorded in
October8AQI
202011AQI
Highest AQI recorded in
March16AQI
Lowest AQI recorded in
May9AQI
Most & Least Polluted Years Over the Last 6 Years
Sliven's annual 2025 AQI (54) shows an average percentage change of 299.2% (worsened AQI) compared to previous years: 2020 (11), 2021 (12), 2022 (9), 2023 (21), 2024 (29).