Worst air pollution ByWard Market Building - Ottawa, today and tomorrow
Today (16 July): Air quality in ByWard Market Building is fair. O3 is fair; AQI and NO2 are medium; PM2.5, PM10, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 12:00 AM (NO2: 40.5/100).
Tomorrow (17 July 2026): Air quality in ByWard Market Building is fair. All pollutants stay as today. Pollution peaks around 11:00 PM (NO2: 40.2/100). Airmine updates local air quality forecasts four times daily.
For long term forecasts and maps, see the Airmine app
Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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ByWard Market Building's air quality reflects its dense historic downtown Ottawa position, with vehicle and market delivery traffic contributing background emissions to this popular market district.
Today - 16 July | Pollution peaks at 00:00
AQI:
Medium
40.5/100
PM2.5 (fine particles):
Good
10.5/100
PM10 (coarse particles):
Good
4.1/100
NO2 (nitrogen dioxide):
Medium
40.5/100
O3 (ozone):
Fair
36.7/100
SO2 (sulfur dioxide):
Good
5.9/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
5.0/100
PM1 (ultrafine particles):
Good
9.8/100
Levels show the poorest local air quality during the day
Tomorrow - 17 July | Pollution peaks at 23:00
AQI:
Medium
40.2/100
PM2.5 (fine particles):
Good
13.2/100
PM10 (coarse particles):
Good
4.8/100
NO2 (nitrogen dioxide):
Medium
40.2/100
O3 (ozone):
Fair
30.9/100
SO2 (sulfur dioxide):
Good
4.0/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
2.9/100
PM1 (ultrafine particles):
Good
11.3/100
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Frequently Asked Questions
Is air quality bad in ByWard Market Building right now?
On 16 July 2026, overall air quality in ByWard Market Building is fair. O3 is the main pollutant at 36.7/100. Pollution peaks around 12:00 AM (NO2: 40.5/100).
Will air quality be worse tomorrow in ByWard Market Building?
On 17 July 2026, air quality conditions in ByWard Market Building will be similar to today, with O3 forecast at fair at 30.9/100. Pollution peaks around 11:00 PM (NO2: 40.2/100).
When is air pollution at its worst in ByWard Market Building?
Seasonal air quality in ByWard Market Building is closely linked to its dense market stalls and downtown Ottawa foot and vehicle traffic. The warmest months typically see the poorest air quality, with heat and heavy traffic driving up smog levels on windless days, whereas fall and winter tend to bring cleaner, more variable conditions. The surrounding Greenbelt helps buffer some neighbourhoods, though downtown corridors still see the sharpest seasonal shifts.
Are air quality levels in ByWard Market Building 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.
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Data provided by Airmine — Last update: 16 July 2026 at 10:33 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.
For long term forecasts and maps, see the Airmine app