Worst air pollution Halton Hills, today and tomorrow

Today (16 August): Air quality in Halton Hills is fair. PM2.5 and O3 are fair; AQI and PM1 are medium; PM10, NO2, SO2, CO, and HCHO are good. Pollution peaks around 4:00 PM (PM1: 40.4/100).
Tomorrow (17 August 2026): Air quality in Halton Hills is fair. All pollutants stay as today. Pollution peaks around 4:00 PM (PM1: 41.1/100). 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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Halton Hills' air quality benefits from its Niagara Escarpment position providing natural buffering, with vehicle traffic on Highway 401 the primary local source amid generally good regional wind dispersal.

Today - 16 August | Pollution peaks at 16:00

AQI:

Medium

40.4/100

PM2.5 (fine particles):

Fair

34.4/100

PM10 (coarse particles):

Good

10.0/100

NO2 (nitrogen dioxide):

Good

3.4/100

O3 (ozone):

Fair

30.3/100

SO2 (sulfur dioxide):

Good

2.0/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

13.9/100

PM1 (ultrafine particles):

Medium

40.4/100

Levels show the poorest local air quality during the day

Tomorrow - 17 August | Pollution peaks at 16:00

AQI:

Medium

41.1/100

PM2.5 (fine particles):

Fair

37.2/100

PM10 (coarse particles):

Good

10.9/100

NO2 (nitrogen dioxide):

Good

2.7/100

O3 (ozone):

Fair

38.9/100

SO2 (sulfur dioxide):

Good

1.7/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

12.7/100

PM1 (ultrafine particles):

Medium

41.1/100

Pollen forecast in Halton Hills

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Air quality forecasts for neighbourhoods and landmarks in Halton Hills

Sports venues in Halton Hills

Frequently Asked Questions

Is air quality bad in Halton Hills right now?

On 16 August 2026, overall air quality in Halton Hills is fair. PM2.5 is the main pollutant at 34.4/100. Pollution peaks around 4:00 PM (PM1: 40.4/100).

Will air quality be worse tomorrow in Halton Hills?

On 17 August 2026, air quality conditions in Halton Hills will be similar to today, with O3 forecast at fair at 38.9/100. Pollution peaks around 4:00 PM (PM1: 41.1/100).

When is air pollution at its worst in Halton Hills?

In Halton Hills, air quality changes through the year largely because of farmland and escarpment terrain west of Toronto. Air quality is generally good, though spring and fall fieldwork stir up dust and occasional agricultural burning, and summer humidity can trap haze close to the ground. The surrounding open land generally keeps air quality good outside of the busiest farming weeks.

Are air quality levels in Halton Hills 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: 17 August 2026 at 02:28 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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