St. Thomas Health Impact
St. Thomas averaged 6.7 ug/m3 PM2.5, equal to 1.3x the WHO annual PM2.5 guideline and about 0.3 cigarettes per day by the simple AQI Now indicator. The page uses OpenAQ-derived daily history for 1 mapped monitoring location in Ontario, Canada.
Search city analytics
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 health page measures
Translate PM2.5 exposure into WHO exceedance and a simple cigarette-equivalent indicator.
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.