Letterkenny, Lifford, Donegal, Ireland 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
Letterkenny, Lifford, Donegal, Ireland
AQI Trends: Highest and Lowest
Same Day Analysis (23rd September ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 4th highest AQI at 25 of Good air quality, showing improvement over 2024, 2023 and 2021 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 23rd Sep - 24th Sep 2025
Letterkenny, Lifford, Donegal, Ireland
6 AM23rd Sep 2025
8 PM
5 AM24th Sep 2025
26AQI
23AQI
25AQI
16AQI
In the last 24 hours,
Letterkenny's AQI reached its highest point of 26 at 10 AM during the Day, while the lowest point, 16, was recorded at 5 AM during the Night between 23rd Sep and 24th Sep 2025.
Day & Night AQI Trend : Aug - Sep 2025
Letterkenny, Lifford, Donegal, Ireland
17°C13/24°C
14°C10/17°C
13°C10/18°C
13°C12/15°C
14°C11/18°C
13°C11/17°C
13°C12/17°C
13°C11/15°C
12°C7/17°C
12°C8/15°C
12°C7/17°C
13°C9/16°C
15°C10/18°C
14°C7/17°C
11°C6/16°C
13°C8/17°C
13°C10/16°C
11°C9/13°C
11°C8/14°C
10°C7/14°C
11°C8/14°C
12°C10/15°C
12°C10/15°C
13°C10/16°C
13°C12/15°C
13°C8/15°C
9°C7/12°C
8°C5/12°C
8°C4/13°C
8°C3/14°C
--°C/°C
21AQI
20AQI
21AQI
20AQI
2025 Days Vs Air Quality
Letterkenny, Lifford, Donegal, Ireland
82%
218
18%
47
0.3%
1
Total number of days with different AQI categories in last 267 days in 2025 (98 days remaining)
Under WHO’s Safe Air Quality Limits: 82%
Health Risk Level:
Low
In 2025, 82% of 267 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
Letterkenny, Lifford, Donegal, Ireland
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
35AQI
57AQI
64AQI
70AQI
99AQI
55AQI
39AQI
67AQI
81AQI
107AQI
67AQI
64AQI
25AQI
24AQI
23AQI
30AQI
26AQI
26AQI
36AQI
46AQI
44AQI
62AQI
43AQI
35AQI
44AQI
50AQI
52AQI
55AQI
49AQI
43AQI
43AQI
58AQI
26AQI
24AQI
25AQI
35AQI
64AQI
51AQI
59AQI
69AQI
59AQI
49AQI
55AQI
54AQI
56AQI
60AQI
48AQI
65AQI
66AQI
61AQI
30AQI
34AQI
31AQI
34AQI
38AQI
30AQI
29AQI
39AQI
49AQI
34AQI
69AQI
30AQI
30AQI
27AQI
37AQI
36AQI
44AQI
73AQI
63AQI
39AQI
33AQI
32AQI
37AQI
52AQI
52AQI
23AQI
28AQI
58AQI
92AQI
70AQI
70AQI
34AQI
45AQI
24AQI
33AQI
21AQI
25AQI
36AQI
46AQI
37AQI
29AQI
38AQI
51AQI
56AQI
54AQI
41AQI
53AQI
58AQI
55AQI
53AQI
56AQI
62AQI
37AQI
17AQI
21AQI
21AQI
19AQI
20AQI
21AQI
41AQI
41AQI
32AQI
18AQI
39AQI
36AQI
27AQI
17AQI
22AQI
29AQI
42AQI
44AQI
24AQI
25AQI
17AQI
21AQI
22AQI
23AQI
25AQI
42AQI
52AQI
39AQI
23AQI
36AQI
26AQI
30AQI
25AQI
24AQI
23AQI
22AQI
29AQI
32AQI
26AQI
26AQI
20AQI
17AQI
18AQI
16AQI
18AQI
15AQI
20AQI
16AQI
18AQI
23AQI
23AQI
24AQI
21AQI
17AQI
16AQI
24AQI
70AQI
47AQI
34AQI
31AQI
33AQI
30AQI
27AQI
26AQI
35AQI
23AQI
23AQI
27AQI
40AQI
40AQI
21AQI
19AQI
16AQI
15AQI
17AQI
17AQI
25AQI
18AQI
14AQI
14AQI
14AQI
19AQI
15AQI
15AQI
16AQI
18AQI
15AQI
17AQI
20AQI
20AQI
22AQI
21AQI
17AQI
18AQI
19AQI
16AQI
16AQI
17AQI
17AQI
19AQI
48AQI
59AQI
55AQI
31AQI
30AQI
21AQI
17AQI
15AQI
19AQI
19AQI
19AQI
19AQI
22AQI
25AQI
31AQI
26AQI
23AQI
29AQI
24AQI
24AQI
29AQI
48AQI
40AQI
34AQI
37AQI
36AQI
31AQI
33AQI
23AQI
20AQI
20AQI
22AQI
21AQI
27AQI
24AQI
22AQI
19AQI
19AQI
17AQI
22AQI
25AQI
22AQI
18AQI
17AQI
18AQI
17AQI
23AQI
21AQI
19AQI
18AQI
19AQI
19AQI
16AQI
18AQI
18AQI
17AQI
18AQI
24AQI
21AQI
27AQI
20AQI
24AQI
25AQI
50AQI
46AQI
43AQI
37AQI
26AQI
27AQI
22AQI
26AQI
20AQI
No. of days
202533AQI
Highest AQI recorded in
January50AQI
Lowest AQI recorded in
September20AQI
202437AQI
Highest AQI recorded in
January63AQI
Lowest AQI recorded in
July20AQI
202337AQI
Highest AQI recorded in
November66AQI
Lowest AQI recorded in
July16AQI
202239AQI
Highest AQI recorded in
December66AQI
Lowest AQI recorded in
June9AQI
202135AQI
Highest AQI recorded in
December58AQI
Lowest AQI recorded in
July24AQI
Most & Least Polluted Years Over the Last 5 Years
Letterkenny's annual 2025 AQI (33) shows an average percentage change of -10.2% (improved AQI) compared to previous years: 2021 (35), 2022 (39), 2023 (37), 2024 (37).