Longueuil, Quebec, Canada 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
Longueuil, Quebec, Canada
AQI Trends: Highest and Lowest
Same Day Analysis (26th September):
On this day, AQI across the 5 years varied significantly: 2026 ranks 3rd highest AQI at 27 of Good air quality, showing improvement over 2023 and 2022 on the same day.
Day & Night AQI Trend: 26th Sep - 27th Sep 2026
Longueuil, Quebec, Canada
6 AM26th Sep 2026
7 PM
5 AM27th Sep 2026
40AQI
20AQI
37AQI
21AQI
In the last 24 hours,
Longueuil's AQI reached its highest point of 40 at 12 PM during the Day, while the lowest point, 20, was recorded at 1 PM during the Day between 26th Sep and 27th Sep 2026.
Day & Night AQI Trend : Aug - Sep 2026
Longueuil, Quebec, Canada
18°C11/27°C
20°C17/24°C
19°C12/28°C
20°C14/29°C
20°C15/27°C
22°C19/28°C
21°C17/25°C
18°C16/22°C
17°C12/23°C
20°C12/30°C
19°C16/25°C
18°C14/22°C
20°C14/24°C
15°C10/21°C
17°C10/24°C
19°C17/22°C
15°C12/19°C
14°C9/18°C
19°C15/25°C
18°C13/24°C
16°C11/21°C
12°C7/17°C
13°C9/20°C
13°C10/16°C
12°C7/18°C
13°C7/19°C
14°C8/21°C
16°C10/23°C
17°C13/23°C
16°C13/20°C
30AQI
24AQI
33AQI
25AQI
2026 Days Vs Air Quality
Longueuil, Quebec, Canada
95%
252
5%
14
Total number of days with different AQI categories in last 270 days in 2026 (95 days remaining)
Under WHO’s Safe Air Quality Limits: 95%
Health Risk Level:
Very Low
In 2026, 95% of 270 days were within WHO’s safe air quality limits. The risk of health issues is Very Low, but health impacts are still unclear.
Annual Air Quality Insights
Longueuil, Quebec, Canada
AQI levels in 2026
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
17AQI (US)
32AQI (US)
19AQI (US)
44AQI (US)
44AQI (US)
59AQI (US)
58AQI (US)
66AQI (US)
43AQI (US)
16AQI (US)
17AQI (US)
18AQI (US)
48AQI (US)
40AQI (US)
34AQI (US)
16AQI (US)
40AQI (US)
35AQI (US)
46AQI (US)
22AQI (US)
29AQI (US)
49AQI (US)
54AQI (US)
48AQI (US)
46AQI (US)
48AQI (US)
44AQI (US)
47AQI (US)
52AQI (US)
50AQI (US)
45AQI (US)
48AQI (US)
49AQI (US)
50AQI (US)
54AQI (US)
50AQI (US)
41AQI (US)
39AQI (US)
45AQI (US)
46AQI (US)
46AQI (US)
47AQI (US)
45AQI (US)
52AQI (US)
49AQI (US)
42AQI (US)
44AQI (US)
45AQI (US)
42AQI (US)
41AQI (US)
43AQI (US)
37AQI (US)
35AQI (US)
40AQI (US)
44AQI (US)
42AQI (US)
35AQI (US)
35AQI (US)
38AQI (US)
42AQI (US)
53AQI (US)
46AQI (US)
45AQI (US)
42AQI (US)
38AQI (US)
40AQI (US)
39AQI (US)
40AQI (US)
34AQI (US)
42AQI (US)
42AQI (US)
40AQI (US)
37AQI (US)
36AQI (US)
36AQI (US)
34AQI (US)
33AQI (US)
32AQI (US)
36AQI (US)
36AQI (US)
36AQI (US)
41AQI (US)
36AQI (US)
34AQI (US)
30AQI (US)
30AQI (US)
35AQI (US)
31AQI (US)
28AQI (US)
25AQI (US)
32AQI (US)
34AQI (US)
28AQI (US)
31AQI (US)
29AQI (US)
28AQI (US)
27AQI (US)
31AQI (US)
28AQI (US)
31AQI (US)
33AQI (US)
29AQI (US)
33AQI (US)
34AQI (US)
34AQI (US)
30AQI (US)
34AQI (US)
34AQI (US)
30AQI (US)
28AQI (US)
25AQI (US)
28AQI (US)
32AQI (US)
33AQI (US)
29AQI (US)
25AQI (US)
23AQI (US)
26AQI (US)
27AQI (US)
25AQI (US)
21AQI (US)
29AQI (US)
32AQI (US)
31AQI (US)
28AQI (US)
28AQI (US)
34AQI (US)
32AQI (US)
30AQI (US)
29AQI (US)
25AQI (US)
45AQI (US)
53AQI (US)
56AQI (US)
57AQI (US)
54AQI (US)
49AQI (US)
44AQI (US)
44AQI (US)
51AQI (US)
48AQI (US)
45AQI (US)
28AQI (US)
26AQI (US)
18AQI (US)
19AQI (US)
20AQI (US)
26AQI (US)
27AQI (US)
24AQI (US)
22AQI (US)
24AQI (US)
27AQI (US)
25AQI (US)
20AQI (US)
25AQI (US)
24AQI (US)
27AQI (US)
25AQI (US)
26AQI (US)
22AQI (US)
23AQI (US)
23AQI (US)
25AQI (US)
26AQI (US)
25AQI (US)
23AQI (US)
23AQI (US)
21AQI (US)
23AQI (US)
22AQI (US)
24AQI (US)
25AQI (US)
27AQI (US)
28AQI (US)
28AQI (US)
26AQI (US)
26AQI (US)
27AQI (US)
28AQI (US)
29AQI (US)
26AQI (US)
27AQI (US)
29AQI (US)
30AQI (US)
27AQI (US)
28AQI (US)
32AQI (US)
31AQI (US)
33AQI (US)
32AQI (US)
34AQI (US)
39AQI (US)
37AQI (US)
34AQI (US)
44AQI (US)
43AQI (US)
41AQI (US)
41AQI (US)
28AQI (US)
25AQI (US)
30AQI (US)
41AQI (US)
41AQI (US)
40AQI (US)
51AQI (US)
39AQI (US)
34AQI (US)
47AQI (US)
42AQI (US)
44AQI (US)
31AQI (US)
38AQI (US)
38AQI (US)
41AQI (US)
40AQI (US)
40AQI (US)
27AQI (US)
29AQI (US)
35AQI (US)
26AQI (US)
27AQI (US)
26AQI (US)
30AQI (US)
32AQI (US)
27AQI (US)
25AQI (US)
29AQI (US)
28AQI (US)
27AQI (US)
28AQI (US)
24AQI (US)
31AQI (US)
28AQI (US)
26AQI (US)
25AQI (US)
28AQI (US)
22AQI (US)
26AQI (US)
27AQI (US)
26AQI (US)
26AQI (US)
25AQI (US)
25AQI (US)
21AQI (US)
24AQI (US)
29AQI (US)
28AQI (US)
28AQI (US)
33AQI (US)
35AQI (US)
43AQI (US)
29AQI (US)
29AQI (US)
26AQI (US)
26AQI (US)
28AQI (US)
31AQI (US)
23AQI (US)
30AQI (US)
28AQI (US)
24AQI (US)
24AQI (US)
27AQI (US)
33AQI (US)
27AQI (US)
40AQI (US)
44AQI (US)
37AQI (US)
30AQI (US)
35AQI (US)
25AQI (US)
34AQI (US)
31AQI (US)
28AQI (US)
No. of days
202634AQI (US)
Highest AQI (US) recorded in
February44AQI (US)
Lowest AQI (US) recorded in
June25AQI (US)
202533AQI (US)
Highest AQI (US) recorded in
July40AQI (US)
Lowest AQI (US) recorded in
April23AQI (US)
202431AQI (US)
Highest AQI (US) recorded in
December38AQI (US)
Lowest AQI (US) recorded in
November24AQI (US)
202336AQI (US)
Highest AQI (US) recorded in
June54AQI (US)
Lowest AQI (US) recorded in
November27AQI (US)
202233AQI (US)
Highest AQI (US) recorded in
January44AQI (US)
Lowest AQI (US) recorded in
August23AQI (US)
202132AQI (US)
Highest AQI (US) recorded in
August41AQI (US)
Lowest AQI (US) recorded in
September22AQI (US)
202025AQI (US)
Highest AQI (US) recorded in
November34AQI (US)
Lowest AQI (US) recorded in
October21AQI (US)
Most & Least Polluted Years Over the Last 7 Years
Longueuil's annual 2026 AQI (US) (34) shows an average percentage change of 8.7% (worsened AQI (US)) compared to previous years: 2020 (25), 2021 (32), 2022 (33), 2023 (36), 2024 (31), 2025 (33).