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 (3rd June):
On this day, AQI across the 5 years varied significantly: 2026 ranks 3rd highest AQI at 38 of Good air quality, showing improvement over 2023 and 2022 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 2nd Jun - 3rd Jun 2026
St Thomas, Ontario, Canada
6 AM2nd Jun 2026
8 PM
5 AM3rd Jun 2026
34AQI
15AQI
152AQI
26AQI
In the last 24 hours,
St Thomas's AQI reached its highest point of 152 at 4 AM during the Night, while the lowest point, 15, was recorded at 7 PM during the Day between 2nd Jun and 3rd Jun 2026.
Day & Night AQI Trend : May - Jun 2026
St Thomas, Ontario, Canada
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
18°C9/27°C
44AQI
35AQI
44AQI
39AQI
2026 Days Vs Air Quality
St Thomas, Ontario, Canada
79%
119
20%
30
1%
2
Total number of days with different AQI categories in last 154 days in 2026 (211 days remaining)
Under WHO’s Safe Air Quality Limits: 79%
Health Risk Level:
Low
In 2026, 79% of 154 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)
38AQI (US)
35AQI (US)
56AQI (US)
49AQI (US)
34AQI (US)
37AQI (US)
33AQI (US)
No. of days
202642AQI (US)
Highest AQI (US) recorded in
February56AQI (US)
Lowest AQI (US) recorded in
June33AQI (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).