Hamilton Downtown, Hamilton, Ontario, 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
Hamilton Downtown, Hamilton, Ontario, Canada
AQI Trends: Highest and Lowest
Same Day Analysis (18th September ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 3rd highest AQI at 45 of Good air quality, showing improvement over 2024 and 2022 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 18th Sep - 19th Sep 2025
Hamilton Downtown, Hamilton, Ontario, Canada
6 AM18th Sep 2025
7 PM
5 AM19th Sep 2025
54AQI
42AQI
52AQI
20AQI
In the last 24 hours,
Hamilton Downtown's AQI reached its highest point of 54 at 8 AM during the Day, while the lowest point, 20, was recorded at 5 AM during the Night between 18th Sep and 19th Sep 2025.
Day & Night AQI Trend : Aug - Sep 2025
Hamilton Downtown, Hamilton, Ontario, Canada
20°C18/22°C
20°C17/26°C
22°C14/31°C
22°C15/28°C
21°C17/24°C
19°C14/23°C
17°C11/22°C
17°C10/23°C
17°C12/24°C
15°C10/20°C
16°C9/22°C
18°C10/26°C
19°C12/25°C
20°C14/28°C
21°C12/30°C
18°C14/21°C
18°C12/27°C
16°C10/23°C
15°C10/19°C
15°C8/20°C
17°C9/26°C
19°C12/27°C
20°C13/27°C
20°C13/26°C
20°C12/27°C
21°C14/28°C
18°C15/22°C
17°C12/22°C
18°C12/25°C
21°C11/32°C
--°C/°C
32AQI
30AQI
33AQI
30AQI
2025 Days Vs Air Quality
Hamilton Downtown, Hamilton, Ontario, Canada
84%
218
16%
42
0.3%
1
Total number of days with different AQI categories in last 262 days in 2025 (103 days remaining)
Under WHO’s Safe Air Quality Limits: 84%
Health Risk Level:
Low
In 2025, 84% of 262 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
Hamilton Downtown, Hamilton, Ontario, Canada
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
21AQI
20AQI
23AQI
26AQI
25AQI
22AQI
22AQI
25AQI
24AQI
45AQI
65AQI
52AQI
43AQI
29AQI
27AQI
54AQI
45AQI
27AQI
26AQI
24AQI
24AQI
32AQI
45AQI
29AQI
54AQI
33AQI
27AQI
27AQI
25AQI
25AQI
58AQI
26AQI
30AQI
61AQI
24AQI
26AQI
38AQI
27AQI
48AQI
34AQI
29AQI
49AQI
28AQI
30AQI
30AQI
38AQI
29AQI
26AQI
26AQI
22AQI
21AQI
25AQI
49AQI
61AQI
54AQI
57AQI
36AQI
44AQI
24AQI
27AQI
25AQI
31AQI
38AQI
54AQI
25AQI
31AQI
33AQI
29AQI
32AQI
33AQI
26AQI
35AQI
61AQI
62AQI
31AQI
16AQI
24AQI
47AQI
30AQI
17AQI
17AQI
26AQI
24AQI
20AQI
19AQI
22AQI
22AQI
20AQI
22AQI
24AQI
17AQI
20AQI
29AQI
21AQI
23AQI
17AQI
19AQI
16AQI
19AQI
29AQI
38AQI
37AQI
34AQI
33AQI
17AQI
14AQI
18AQI
40AQI
42AQI
19AQI
23AQI
15AQI
24AQI
37AQI
50AQI
31AQI
14AQI
29AQI
39AQI
23AQI
30AQI
34AQI
18AQI
17AQI
19AQI
27AQI
30AQI
19AQI
26AQI
24AQI
22AQI
32AQI
41AQI
40AQI
39AQI
35AQI
28AQI
18AQI
18AQI
16AQI
18AQI
17AQI
11AQI
12AQI
13AQI
18AQI
33AQI
36AQI
27AQI
31AQI
26AQI
15AQI
19AQI
33AQI
58AQI
50AQI
62AQI
61AQI
76AQI
63AQI
44AQI
57AQI
66AQI
38AQI
28AQI
38AQI
39AQI
44AQI
36AQI
25AQI
38AQI
49AQI
49AQI
52AQI
54AQI
43AQI
41AQI
35AQI
33AQI
38AQI
42AQI
38AQI
41AQI
49AQI
33AQI
44AQI
51AQI
48AQI
33AQI
40AQI
36AQI
53AQI
44AQI
39AQI
46AQI
58AQI
65AQI
37AQI
21AQI
28AQI
24AQI
44AQI
24AQI
25AQI
33AQI
30AQI
53AQI
37AQI
53AQI
48AQI
47AQI
85AQI
52AQI
33AQI
76AQI
103AQI
94AQI
75AQI
74AQI
82AQI
65AQI
62AQI
59AQI
55AQI
42AQI
49AQI
58AQI
58AQI
39AQI
16AQI
24AQI
22AQI
17AQI
25AQI
29AQI
30AQI
20AQI
18AQI
20AQI
26AQI
20AQI
21AQI
26AQI
36AQI
36AQI
35AQI
27AQI
40AQI
22AQI
22AQI
22AQI
27AQI
39AQI
41AQI
38AQI
51AQI
53AQI
50AQI
40AQI
39AQI
45AQI
33AQI
35AQI
30AQI
26AQI
25AQI
44AQI
42AQI
45AQI
37AQI
No. of days
202535AQI
Highest AQI recorded in
August45AQI
Lowest AQI recorded in
May25AQI
202435AQI
Highest AQI recorded in
May40AQI
Lowest AQI recorded in
November25AQI
202343AQI
Highest AQI recorded in
June66AQI
Lowest AQI recorded in
October31AQI
202238AQI
Highest AQI recorded in
May45AQI
Lowest AQI recorded in
August20AQI
202138AQI
Highest AQI recorded in
April43AQI
Lowest AQI recorded in
October29AQI
202036AQI
Highest AQI recorded in
May48AQI
Lowest AQI recorded in
October27AQI
Most & Least Polluted Years Over the Last 6 Years
Hamilton Downtown's annual 2025 AQI (35) shows an average percentage change of -6.7% (improved AQI) compared to previous years: 2020 (36), 2021 (38), 2022 (38), 2023 (43), 2024 (35).