St Thomas, Ontario, Canada Historical Air Quality Analysis
Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!
June Air Quality Analysis
St Thomas, Ontario, Canada
AQI Trends: Highest and Lowest
Same Day Analysis (2nd June):
On this day, AQI across the 5 years varied significantly: 2026 ranks 4th highest AQI at 28 of Good air quality, showing improvement over 2024, 2023 and 2022 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 1st Jun - 2nd Jun 2026
St Thomas, Ontario, Canada
6 AM1st Jun 2026
8 PM
5 AM2nd Jun 2026
34AQI
24AQI
34AQI
21AQI
In the last 24 hours,
St Thomas's AQI reached its highest point of 34 at 12 PM during the Day, while the lowest point, 21, was recorded at 2 AM during the Night between 1st Jun and 2nd Jun 2026.
Day & Night AQI Trend : May - Jun 2026
St Thomas, Ontario, Canada
14°C6/23°C
14°C9/20°C
9°C6/13°C
8°C3/12°C
9°C3/14°C
12°C7/19°C
9°C3/14°C
9°C3/14°C
7°C0/14°C
10°C6/14°C
11°C5/17°C
11°C3/18°C
15°C8/23°C
20°C14/27°C
22°C14/31°C
21°C17/27°C
11°C7/12°C
10°C4/17°C
13°C6/19°C
11°C10/12°C
14°C12/17°C
16°C13/20°C
16°C7/25°C
20°C14/28°C
16°C10/22°C
17°C7/27°C
14°C8/19°C
15°C7/23°C
16°C8/22°C
17°C8/25°C
45AQI
35AQI
41AQI
38AQI
2026 Days Vs Air Quality
St Thomas, Ontario, Canada
79%
118
20%
30
1%
2
Total number of days with different AQI categories in last 153 days in 2026 (212 days remaining)
Under WHO’s Safe Air Quality Limits: 79%
Health Risk Level:
Low
In 2026, 79% of 153 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
St Thomas, Ontario, Canada
AQI levels in 2026
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
9AQI (US)
11AQI (US)
19AQI (US)
20AQI (US)
59AQI (US)
83AQI (US)
50AQI (US)
49AQI (US)
20AQI (US)
16AQI (US)
15AQI (US)
20AQI (US)
30AQI (US)
24AQI (US)
12AQI (US)
17AQI (US)
33AQI (US)
21AQI (US)
29AQI (US)
23AQI (US)
23AQI (US)
52AQI (US)
60AQI (US)
48AQI (US)
50AQI (US)
48AQI (US)
43AQI (US)
42AQI (US)
49AQI (US)
59AQI (US)
42AQI (US)
46AQI (US)
74AQI (US)
73AQI (US)
44AQI (US)
54AQI (US)
76AQI (US)
39AQI (US)
42AQI (US)
46AQI (US)
47AQI (US)
38AQI (US)
38AQI (US)
51AQI (US)
83AQI (US)
79AQI (US)
102AQI (US)
114AQI (US)
62AQI (US)
46AQI (US)
50AQI (US)
41AQI (US)
33AQI (US)
39AQI (US)
43AQI (US)
58AQI (US)
31AQI (US)
71AQI (US)
38AQI (US)
37AQI (US)
50AQI (US)
58AQI (US)
95AQI (US)
75AQI (US)
58AQI (US)
80AQI (US)
35AQI (US)
34AQI (US)
59AQI (US)
44AQI (US)
38AQI (US)
43AQI (US)
35AQI (US)
32AQI (US)
37AQI (US)
34AQI (US)
36AQI (US)
64AQI (US)
81AQI (US)
40AQI (US)
58AQI (US)
39AQI (US)
34AQI (US)
45AQI (US)
61AQI (US)
29AQI (US)
31AQI (US)
35AQI (US)
42AQI (US)
66AQI (US)
30AQI (US)
30AQI (US)
39AQI (US)
28AQI (US)
31AQI (US)
27AQI (US)
27AQI (US)
37AQI (US)
49AQI (US)
33AQI (US)
30AQI (US)
47AQI (US)
46AQI (US)
48AQI (US)
41AQI (US)
50AQI (US)
40AQI (US)
33AQI (US)
29AQI (US)
33AQI (US)
37AQI (US)
27AQI (US)
28AQI (US)
32AQI (US)
27AQI (US)
30AQI (US)
28AQI (US)
26AQI (US)
26AQI (US)
23AQI (US)
30AQI (US)
32AQI (US)
40AQI (US)
39AQI (US)
27AQI (US)
34AQI (US)
30AQI (US)
27AQI (US)
28AQI (US)
42AQI (US)
22AQI (US)
40AQI (US)
56AQI (US)
65AQI (US)
63AQI (US)
44AQI (US)
49AQI (US)
44AQI (US)
44AQI (US)
51AQI (US)
40AQI (US)
44AQI (US)
32AQI (US)
29AQI (US)
24AQI (US)
24AQI (US)
23AQI (US)
28AQI (US)
32AQI (US)
28AQI (US)
35AQI (US)
56AQI (US)
49AQI (US)
34AQI (US)
37AQI (US)
30AQI (US)
No. of days
202642AQI (US)
Highest AQI (US) recorded in
February56AQI (US)
Lowest AQI (US) recorded in
June30AQI (US)
202534AQI (US)
Highest AQI (US) recorded in
August49AQI (US)
Lowest AQI (US) recorded in
May22AQI (US)
202433AQI (US)
Highest AQI (US) recorded in
January37AQI (US)
Lowest AQI (US) recorded in
November26AQI (US)
202341AQI (US)
Highest AQI (US) recorded in
June73AQI (US)
Lowest AQI (US) recorded in
October30AQI (US)
202233AQI (US)
Highest AQI (US) recorded in
June37AQI (US)
Lowest AQI (US) recorded in
August21AQI (US)
202136AQI (US)
Highest AQI (US) recorded in
July48AQI (US)
Lowest AQI (US) recorded in
November27AQI (US)
202033AQI (US)
Highest AQI (US) recorded in
June37AQI (US)
Lowest AQI (US) recorded in
October28AQI (US)
Most & Least Polluted Years Over the Last 7 Years
St Thomas's annual 2026 AQI (US) (42) shows an average percentage change of 20.7% (worsened AQI (US)) compared to previous years: 2020 (33), 2021 (36), 2022 (33), 2023 (41), 2024 (33), 2025 (34).