London, Ontario, Canada 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
London, Ontario, Canada
AQI Trends: Highest and Lowest
Same Day Analysis (4th October ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 1st highest AQI at 76 of Moderate air quality on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 4th Oct - 5th Oct 2025
London, Ontario, Canada
7 AM4th Oct 2025
7 PM
6 AM5th Oct 2025
73AQI
52AQI
64AQI
56AQI
In the last 24 hours,
London's AQI reached its highest point of 73 at 8 AM during the Day, while the lowest point, 52, was recorded at 7 PM during the Day between 4th Oct and 5th Oct 2025.
Day & Night AQI Trend : Sep - Oct 2025
London, Ontario, Canada
17°C10/25°C
14°C7/19°C
14°C5/21°C
13°C2/20°C
15°C5/24°C
17°C7/25°C
18°C8/28°C
18°C8/28°C
18°C11/23°C
20°C10/30°C
19°C12/29°C
19°C10/30°C
19°C9/30°C
19°C10/29°C
18°C13/24°C
17°C11/24°C
20°C12/29°C
20°C17/26°C
21°C17/26°C
19°C16/24°C
18°C15/21°C
19°C14/27°C
19°C12/27°C
20°C14/29°C
18°C8/30°C
18°C8/29°C
15°C8/23°C
15°C7/26°C
17°C7/30°C
20°C10/31°C
--°C/°C
37AQI
37AQI
37AQI
36AQI
2025 Days Vs Air Quality
London, Ontario, Canada
83%
230
16%
43
1%
4
Total number of days with different AQI categories in last 278 days in 2025 (87 days remaining)
Under WHO’s Safe Air Quality Limits: 83%
Health Risk Level:
Low
In 2025, 83% of 278 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
London, Ontario, Canada
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
20AQI
24AQI
23AQI
26AQI
24AQI
22AQI
24AQI
26AQI
26AQI
49AQI
64AQI
49AQI
35AQI
27AQI
25AQI
50AQI
41AQI
28AQI
28AQI
28AQI
24AQI
29AQI
38AQI
27AQI
48AQI
30AQI
26AQI
29AQI
26AQI
27AQI
52AQI
26AQI
28AQI
54AQI
26AQI
24AQI
32AQI
29AQI
41AQI
36AQI
31AQI
48AQI
29AQI
29AQI
34AQI
42AQI
32AQI
27AQI
27AQI
25AQI
22AQI
27AQI
53AQI
56AQI
52AQI
44AQI
48AQI
49AQI
25AQI
29AQI
28AQI
30AQI
35AQI
35AQI
27AQI
30AQI
33AQI
28AQI
30AQI
30AQI
27AQI
28AQI
53AQI
54AQI
22AQI
16AQI
24AQI
33AQI
25AQI
17AQI
16AQI
18AQI
20AQI
18AQI
19AQI
30AQI
36AQI
51AQI
40AQI
21AQI
17AQI
18AQI
24AQI
20AQI
21AQI
19AQI
20AQI
14AQI
23AQI
27AQI
36AQI
30AQI
38AQI
29AQI
17AQI
16AQI
24AQI
38AQI
44AQI
19AQI
24AQI
15AQI
33AQI
45AQI
42AQI
21AQI
17AQI
26AQI
34AQI
17AQI
31AQI
31AQI
19AQI
21AQI
21AQI
22AQI
29AQI
24AQI
28AQI
31AQI
25AQI
30AQI
30AQI
18AQI
27AQI
31AQI
25AQI
17AQI
16AQI
17AQI
19AQI
15AQI
11AQI
11AQI
21AQI
25AQI
28AQI
21AQI
30AQI
35AQI
28AQI
18AQI
29AQI
36AQI
68AQI
59AQI
67AQI
68AQI
87AQI
68AQI
55AQI
63AQI
70AQI
52AQI
39AQI
40AQI
39AQI
38AQI
37AQI
27AQI
36AQI
43AQI
46AQI
53AQI
54AQI
44AQI
46AQI
41AQI
32AQI
36AQI
39AQI
32AQI
43AQI
49AQI
48AQI
54AQI
54AQI
46AQI
38AQI
49AQI
50AQI
50AQI
44AQI
40AQI
51AQI
68AQI
74AQI
45AQI
25AQI
28AQI
25AQI
48AQI
26AQI
27AQI
42AQI
33AQI
54AQI
34AQI
42AQI
43AQI
46AQI
107AQI
69AQI
42AQI
113AQI
130AQI
105AQI
94AQI
80AQI
79AQI
59AQI
62AQI
60AQI
53AQI
38AQI
62AQI
74AQI
66AQI
41AQI
16AQI
22AQI
22AQI
19AQI
23AQI
31AQI
26AQI
16AQI
18AQI
24AQI
27AQI
20AQI
24AQI
34AQI
31AQI
30AQI
32AQI
26AQI
39AQI
19AQI
20AQI
24AQI
25AQI
35AQI
42AQI
43AQI
54AQI
56AQI
52AQI
45AQI
47AQI
51AQI
41AQI
35AQI
33AQI
36AQI
36AQI
36AQI
34AQI
34AQI
33AQI
29AQI
24AQI
27AQI
34AQI
31AQI
49AQI
76AQI
32AQI
36AQI
29AQI
26AQI
24AQI
48AQI
46AQI
50AQI
36AQI
48AQI
No. of days
202536AQI
Highest AQI recorded in
August50AQI
Lowest AQI recorded in
May24AQI
202433AQI
Highest AQI recorded in
February39AQI
Lowest AQI recorded in
November26AQI
202343AQI
Highest AQI recorded in
June74AQI
Lowest AQI recorded in
October33AQI
202234AQI
Highest AQI recorded in
December38AQI
Lowest AQI recorded in
August20AQI
202135AQI
Highest AQI recorded in
February40AQI
Lowest AQI recorded in
September28AQI
202032AQI
Highest AQI recorded in
June37AQI
Lowest AQI recorded in
October24AQI
Most & Least Polluted Years Over the Last 6 Years
London's annual 2025 AQI (36) shows an average percentage change of 3.3% (worsened AQI) compared to previous years: 2020 (32), 2021 (35), 2022 (34), 2023 (43), 2024 (33).