St. Thomas Seasonal Pollution
St. Thomas usually records its highest OpenAQ-derived EPA AQI in January and its cleanest month in November. The page uses OpenAQ-derived daily history for 1 mapped monitoring location in Ontario, Canada.
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Average EPA AQI
35
Rank 46 of 158 cities by average AQI
PM2.5
6.7
ug/m3 annualized city average
Seasonality
January
Cleanest: November
Health indicator
0.3
cigarette-equivalent per day
Yearly EPA AQI trend
Seasonal EPA AQI heatmap
JanFebMarAprMayJunJulAugSepOctNovDec
St. Thomas
42
42
27
32
35
36
38
40
37
28
26
35
What this seasonality page measures
Find each city's worst and cleanest months from daily OpenAQ-derived EPA AQI.
For St. Thomas, the current global analytics build covers 347 daily rows from 2024-01-01 to 2024-12-31. The calculations normalize PM2.5 and PM10 observations into US EPA AQI bands so country, city, and tool pages use one consistent method.