Worst air pollution Sarnia, today and tomorrow
Today (9 August): Air quality in Sarnia is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 7:00 AM (O3: 33.2/100).
Tomorrow (10 August 2026): Air quality in Sarnia is fair. All pollutants stay as today. Pollution peaks around 1:00 PM (O3: 31.0/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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Sarnia's air quality reflects its position in Ontario's Chemical Valley, with the petrochemical industrial cluster along the St. Clair River generating some of the province's highest industrial VOC and SO2 concentrations.
Today - 9 August | Pollution peaks at 07:00
AQI:
Fair
33.2/100
PM2.5 (fine particles):
Good
5.5/100
PM10 (coarse particles):
Good
3.9/100
NO2 (nitrogen dioxide):
Good
0.9/100
O3 (ozone):
Fair
33.2/100
SO2 (sulfur dioxide):
Good
0.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
3.6/100
PM1 (ultrafine particles):
Good
4.0/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 13:00
AQI:
Fair
31.0/100
PM2.5 (fine particles):
Good
7.1/100
PM10 (coarse particles):
Good
4.1/100
NO2 (nitrogen dioxide):
Good
1.2/100
O3 (ozone):
Fair
31.0/100
SO2 (sulfur dioxide):
Good
0.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
5.4/100
PM1 (ultrafine particles):
Good
4.5/100
Pollen forecast in Sarnia
View pollen forecastFrequently Asked Questions
Is air quality bad in Sarnia right now?
On 9 August 2026, overall air quality in Sarnia is fair. AQI is the main air quality indicator at 33.2/100. Pollution peaks around 7:00 AM (O3: 33.2/100).
Will air quality be worse tomorrow in Sarnia?
On 10 August 2026, air quality conditions in Sarnia will be similar to today, with AQI forecast at fair at 31.0/100. Pollution peaks around 1:00 PM (O3: 31.0/100).
When is air pollution at its worst in Sarnia?
The air over Sarnia varies through the year, influenced by the petrochemical refineries of "Chemical Valley" along the St. Clair River. Air quality here tends to dip in summer, when heat and industrial output combine, and again briefly in winter when cold, calm air traps emissions near ground level. Wind direction along the river has a strong influence on which neighbourhoods feel the effects most on any given day.
Are air quality levels in Sarnia based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 9 August 2026 at 20:27 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
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