Toronto air quality
Ontario, Canada · Live AQI and hourly forecast for the next 5 days · updated Sat 19:00 local time
Good
Great air. A perfect time to be outside.
- Next 24 hours
- 24–32US AQI, highest around Sat 19:00
- Best time outside
- Sun 02:00–5:00US AQI about 24
- PM2.5 vs WHO guideline
- 0.2×3.0 µg/m³ over 24 h, guideline 15
- Cigarette equivalent
- ≈ 0.1 a dayBerkeley Earth rule of thumb
- European AQI
- Fairlevel 2 of 6
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Pollutants in Toronto right now
| Pollutant | Now | Next 24 h vs WHO | US AQI band |
|---|---|---|---|
| Fine particles (PM2.5) | 3.4 µg/m³ | 0.2× | Good |
| Coarse particles (PM10) | 3.5 µg/m³ | 0.1× | Good |
| Nitrogen dioxide (NO2) | 16 µg/m³ | 0.3× | Good |
| Ozone (O3) | 54 µg/m³ | 0.7× | Good |
| Sulphur dioxide (SO2) | 3.5 µg/m³ | 0.1× | Good |
| Carbon monoxide (CO) | 247 µg/m³ | 0.0× | Good |
| Desert dust | 0 µg/m³ | ||
| Smoke and haze (aerosol optical depth) | 0.06 | ||
| UV index | 0.0 |
“Next 24 h vs WHO” compares the forecast with the World Health Organization’s 2021 guideline levels: 24-hour means of 15 µg/m³ for PM2.5, 45 for PM10, 25 for NO2, 40 for SO2 and 4 mg/m³ for CO, and 100 µg/m³ over 8 hours for ozone. Above 1× is above the guideline.
Next 48 hours
Hourly US AQI. Highest 32 around Sat 19:00, lowest 24 around Sun 02:00.
5-day air quality forecast for Toronto
Daily range of the hourly US AQI, from lowest to highest, on a scale of 0 to 150.
| Day | US AQI | At worst | PM2.5 avg | |
|---|---|---|---|---|
| Sat 26 Sept | 25–34 | 2.7 | ||
| Sun 27 Sept | 24–32 | 3.4 | ||
| Mon 28 Sept | 25–36 | 6.7 | ||
| Tue 29 Sept | 37–54 | 11 | ||
| Wed 30 Sept | 51–54 | 9.8 |
Common questions about the air in Toronto
Is the air in Toronto safe today?
Yes. Right now the US AQI in Toronto is 32, which counts as good. Great air. A perfect time to be outside.
When is the best time to be outside in Toronto?
Sun 02:00–5:00. That is the cleanest stretch in the next 24 hours, with the US AQI averaging about 24. The worst hour is around Sat 19:00, at 32.
What is the main pollutant in Toronto?
Ozone (O3). It drives the index right now, at 54 µg/m³. Formed by sunlight acting on traffic and plant emissions. Highest on hot, still afternoons, often downwind of cities.
How does Toronto's air compare with the WHO guideline?
Within the guideline. Over the next 24 hours PM2.5 averages about 3.0 µg/m³, against the World Health Organization's 24-hour guideline of 15 µg/m³. The other pollutants stay within their guideline levels.
How many cigarettes is a day of Toronto's air?
About 0.1 cigarettes. Over the next 24 hours PM2.5 averages about 3.0 µg/m³. By Berkeley Earth's rule of thumb, 22 µg/m³ breathed for a day is roughly one cigarette.
Will air quality in Toronto improve this week?
Sunday looks cleanest. Its AQI peaks at 32, against 54 on Tuesday, the worst day in the forecast.
Measured near Toronto
| Station | PM2.5 µg/m³ | Measured |
|---|---|---|
| Toronto Downtown AirNow, reference monitor | 11 | Sat 18:00 |
| Unnamed sensor Sensor.Community, low-cost sensor | 6.7 | Sat 19:48 |
| Toronto East AirNow, reference monitor | 5.0 | Sat 18:00 |
Air quality near Toronto
- Detroit 332 km SW
- Ottawa 352 km NE
- Montreal 504 km NE
- Philadelphia 540 km SE
- New York 550 km SE
- Washington, D.C. 563 km S
About this forecast
Forecast from CAMS global via Open-Meteo: the Copernicus Atmosphere Monitoring Service (CAMS) model at about 40 km resolution (10 km inside Europe), refreshed twice a day. Models smooth out street-level peaks, so busy roads and industrial sites can be worse than shown; ground stations, where there are any nearby, show what monitors actually measure. The US AQI follows the US EPA scale and the European AQI the EEA bands. Readings for 43.65°N, 79.38°W, updated 2026-09-26 23:00 UTC.