Is the air in Ottawa safe today?

Yes. Right now the US AQI in Ottawa is 30, which counts as good. Great air. A perfect time to be outside.

When is the best time to be outside in Ottawa?

Sat 04:00–7:00. That is the cleanest stretch in the next 24 hours, with the US AQI averaging about 20. The worst hour is around Fri 12:00, at 30.

What is the main pollutant in Ottawa?

Ozone (O3). It drives the index right now, at 64 µg/m³. Formed by sunlight acting on traffic and plant emissions. Highest on hot, still afternoons, often downwind of cities.

How does Ottawa's air compare with the WHO guideline?

Within the guideline. Over the next 24 hours PM2.5 averages about 1.0 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 Ottawa's air?

Less than a tenth of one. Over the next 24 hours PM2.5 averages about 1.0 µg/m³. By Berkeley Earth's rule of thumb, 22 µg/m³ breathed for a day is roughly one cigarette.

Will air quality in Ottawa improve this week?

Saturday looks cleanest. Its AQI peaks at 31, against 55 on Tuesday, the worst day in the forecast.

Ottawa air quality

Ontario, Canada · Live AQI and hourly forecast for the next 5 days · valid Fri 12:00 local time

Good

US AQI, mostly O₃

Model estimate. Nearby measurements are shown separately.

Great air. A perfect time to be outside.

Next 24 hours: 20–30US AQI, highest around Fri 12:00
Best time outside: Sat 04:00–7:00US AQI about 20
PM_2.5 vs WHO guideline: 0.1×1.0 µg/m³ over 24 h, guideline 15
Cigarette equivalent: ≈ 0 a dayBerkeley Earth rule of thumb

Loading the live globe…

The live globe, centred on Ottawa. Switch pollutants, drag through the next 5 days or press play. Full map →

Pollutants in Ottawa right now

Pollutant	Now	Level	Next 24 h vs WHO
Fine particles PM_2.5	0.9 µg/m³	Good	0.1×
Coarse particles PM₁₀	0.9 µg/m³	Good	0.0×
Nitrogen dioxide NO₂	2.5 µg/m³	Good	0.2×
Ozone O₃	64 µg/m³	Good	0.6×
Sulphur dioxide SO₂	0.9 µg/m³	Good	0.0×
Carbon monoxide CO	142 µg/m³	Good	0.0×
Aerosol optical depth	0.05	Whole atmosphere · dimensionless
Desert dust	0 µg/m³	Modelled surface dust
UV index	1	Low

“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 PM_2.5, 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. Levels follow the US AQI, which is far less strict than the WHO, so air rated Good can still be above a guideline.

Next 48 hours

Hourly US AQI. Highest 33 around Sun 10:00, lowest 20 around Sat 04:00.

Good 0–50Moderate 51–100Sensitive 101–150Unhealthy 151–200Very unhealthy 201–300Hazardous 301+

5-day air quality forecast for Ottawa

Daily range of the hourly US AQI, from lowest to highest, on a scale of 0 to 150.

Day	US AQI	At worst	Worst hour	PM_2.5 avg	UV max
Fri 13 Nov	21–48	Good	0:00	3.2	1 Low
Sat 14 Nov	20–31	Good	13:00	0.7	1 Low
Sun 15 Nov	28–34	Good	15:00	0.6	1 Low
Mon 16 Nov	21–32	Good	12:00	1.5	1 Low
Tue 17 Nov	21–55	Moderate	19:00	6.0	1 Low

Common questions about the air in Ottawa

Is the air in Ottawa safe today?
Yes. Right now the US AQI in Ottawa is 30, which counts as good. Great air. A perfect time to be outside.
When is the best time to be outside in Ottawa?
Sat 04:00–7:00. That is the cleanest stretch in the next 24 hours, with the US AQI averaging about 20. The worst hour is around Fri 12:00, at 30.
What is the main pollutant in Ottawa?
Ozone (O₃). It drives the index right now, at 64 µg/m³. Formed by sunlight acting on traffic and plant emissions. Highest on hot, still afternoons, often downwind of cities.
How does Ottawa's air compare with the WHO guideline?
Within the guideline. Over the next 24 hours PM_2.5 averages about 1.0 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 Ottawa's air?
Less than a tenth of one. Over the next 24 hours PM_2.5 averages about 1.0 µg/m³. By Berkeley Earth's rule of thumb, 22 µg/m³ breathed for a day is roughly one cigarette.
Will air quality in Ottawa improve this week?
Saturday looks cleanest. Its AQI peaks at 31, against 55 on Tuesday, the worst day in the forecast.

Measured near Ottawa

Station and measurements	Distance	US AQI	Level
Ottawa Downtown OpenAQ, reference monitor PM_2.5: 1.0 µg/m³ · Fri 11:00 NO₂: 3.8 µg/m³ · Fri 11:00 O₃: 45 µg/m³ · Fri 11:00	2.2 km	21	Good
Gatineau - Hull AirNow, reference monitor PM_2.5: 1.0 µg/m³ · Fri 11:00 O₃: 47 µg/m³ · Fri 11:00	2.8 km	21	Good
Unnamed sensor OpenAQ, low-cost sensor PM_2.5: 0.0 µg/m³ · Fri 12:00	3.5 km	0	Good

Air quality near Ottawa

US AQI right now. Cleanest nearby: Philadelphia (19); worst: Toronto (30). The tick on each bar is Ottawa, at 30.

Montreal 166 km E 27 Good
Toronto 352 km SW 30 Good
Boston 504 km SE 29 Good
New York 541 km S 28 Good
Philadelphia 610 km S 19 Good
Detroit 682 km SW 24 Good

All 162 cities →

About this forecast

Forecast from CAMS global via Open-Meteo: the Copernicus Atmosphere Monitoring Service (CAMS) model at about 40 km resolution (about 10 km inside Europe). Global runs update every 12 hours and European runs every 24 hours. Models smooth out street-level peaks, so busy roads and industrial sites can be worse than shown. Nearby station measurements are independent observations, not adjustments to the forecast. The point forecast uses Open-Meteo’s CAMS products, including a separate carbon monoxide product; it can differ from the globe’s global grid. The AQI rates each hour on the US EPA scale, the same way the map colors it; official daily figures average over 24 hours (8 for ozone), so they can read lower after a short peak. Readings for 45.42°N, 75.70°W, valid 2026-11-13 17:00 UTC.