Air Quality in Ottawa, Ontario — Live
Live readings from PurpleAir sensors across Ottawa — with free alerts the moment the air turns.
AQI 18 from 5 PurpleAir sensors · Trending down · data from PurpleAir
As of , the air quality in Ottawa, Ontario is AQI 18 — Good and falling — with PM2.5 at 3.3 µg/m³, the median of 5 live PurpleAir sensors reading 6 to 22. Canairy's verdict: Breathe easy.
For scale, that PM2.5 reading is below the World Health Organization's 24-hour guideline of 15 µg/m³. The WHO figure is a daily average and this is a live reading, so read it as a sense of magnitude rather than a formal exceedance — a brief spike and a bad day are not the same thing. More on the WHO guidelines
Pollen today in Ottawa: weeds pollen is the strongest of the three at a very low level, from Google's pollen forecast. Canairy shows the tree, grass and weed forecast beside the air reading on every plan, including the free one.
Free to download · Live data from PurpleAir & public monitors
Live PurpleAir sensor map for Ottawa and Gatineau, Kanata, Orléans, Barrhaven. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Ottawa
The sensors Canairy reads in Ottawa agree right now — all 5 sit in the Good band, a 16-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 1.0 mi SSE | 17 | Good |
| 2.2 mi S | 17 | Good |
| 6.4 mi NNW | 6 | Good |
| 7.4 mi S | 19 | Good |
| 10.2 mi SW | 22 | Good |
Ottawa's air is unremarkable most of the year, and then there was June 2023. On the morning of Tuesday 6 June, Ontario's Ottawa Downtown monitor sat at 10+ on the Air Quality Health Index, the top of the scale, from 7 a.m. straight through to 10 a.m. The underlying calculation ran to 14, double the level at which Environment and Climate Change Canada issues a statement at all. Fine particulate matter measured 267 micrograms per cubic metre at 8 a.m., more than twice what Delhi was breathing that day, and Ottawa had the worst air of any major city in Ontario. Monica Vaswani, a meteorologist with Environment and Climate Change Canada, said it was, in some ways, off the charts.
What Canairy does for Ottawa
A clear verdict
Not just a number — a plain-English call for Ottawa: open the windows, or keep them shut.
Smoke alerts
A push or text the moment the air crosses your threshold — and again when it clears.
A heads-up before it's bad
Trend alerts catch the air turning, so you can close up the house before the smoke settles in.
Every place you care about
Home, work, the kids' school — across Ottawa or across the country, on one screen.
The smoke that reached Ottawa in 2023 came from both sides of the river
The fires burning that week were in and around eastern Ontario and western Quebec, and the wind did the rest. Vaswani warned that northeasterly winds would keep pushing smoke toward the capital, which is why the bad air held rather than passing through in an afternoon. It came back later in the month too, when plumes from fires further north in Quebec drifted down over the region again and pushed the index back to 10+ on a Sunday morning in late June.
The response on the ground was immediate and local. The Ottawa Catholic School Board cancelled a track meet, and the Upper Canada District School Board called off outdoor extracurriculars and kept students inside at recess. Birgit Isernhagen of Ottawa Public Health gave about the plainest advice you will hear from a health unit: if you are doing lots of activity outside and you notice you are dizzy or you cannot breathe, stop what you are doing and go into a space with closed windows and air conditioning.
Ontario runs exactly one air quality monitor in Ottawa
The province's Air Quality Ontario network lists a single station for the city, Ottawa Downtown, station 51001. That one instrument is the source of the hourly AQHI the province publishes and archives for the capital, and it is a good instrument. It is also downtown, and Ottawa is not. The city runs from Kanata in the west to Orléans in the east, with Barrhaven and Riverside South well to the south of the core and Gatineau across the river in another province entirely.
On a day when smoke is arriving on a steady wind, a single number is close enough for everyone. On the more common days, when the air is fine in one part of town and a neighbour is burning damp wood in another, it is not. That gap is the whole reason to read sensors near the addresses you actually use rather than one figure for the region.
When nothing is burning, Ottawa Public Health names two sources
Ottawa Public Health points at residential wood burning and traffic-related air pollution as the local contributors worth doing something about. It attributes roughly 2,300 premature deaths a year in Canada to residential wood smoke and about 1,200 to traffic-related air pollution, using 2015 figures, and its position on the first is blunt: Ottawa Public Health does not recommend burning wood or other biomass for any reason in built-up areas. That is stronger language than most Canadian health units use.
On traffic, the guidance is about distance. Exposure to traffic-related pollution falls off sharply once you are 50 to 100 metres from a busy road, which is a useful thing to know if you are choosing where a child sleeps or where you run. Neither of these sources produces a dramatic sky. They produce a number that is quietly higher than it needs to be, on the street where you live, which is exactly what a nearby sensor is good at showing.
Ottawa air quality FAQ
What is the air quality in Ottawa right now?
As of September 10, 2026 at 8:10 AM EDT, the air quality in Ottawa, Ontario is AQI 18 — Good — with PM2.5 at 3.3 µg/m³, the median of 5 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why is there smoke in Ottawa today?
In summer it is almost always wildfire smoke carried in on the wind, usually from fires in northern or western Quebec or in eastern Ontario, rather than from anything burning near the city. That was the pattern in June 2023, when smoke from fires in and around eastern Ontario and western Quebec pushed the downtown index to the top of the scale for hours at a time. Outside fire season, a smoky smell on a cold, still evening is more likely to be a neighbourhood wood stove or fireplace. The live reading on this page will tell you which kind of day it is far faster than trying to judge by eye.
Canada reports the AQHI, so why does this page show a different number?
Environment and Climate Change Canada publishes the Air Quality Health Index, a 1 to 10+ scale built from three pollutants measured together: fine particulate matter, ground-level ozone and nitrogen dioxide. PurpleAir sensors measure fine particulate matter only, so an AQHI cannot honestly be calculated from them. This page shows the US EPA AQI instead, which is derived from PM2.5 directly and is the scale most air quality apps use. It is not an AQHI and Canairy does not present it as one. For the official AQHI for Ottawa, Environment Canada and Air Quality Ontario are the sources.
How bad did Ottawa's air actually get in June 2023?
On the morning of 6 June 2023 the Ottawa Downtown monitor read 10+ on the AQHI from 7 a.m. to 10 a.m., with the underlying calculation reaching 14, twice the threshold at which Environment and Climate Change Canada issues an air quality statement. Fine particulate matter hit 267 micrograms per cubic metre at 8 a.m., more than double Delhi's level that day, and Ottawa had the worst air of any major Ontario city. School boards cancelled outdoor activities and kept children in at recess.
What the AQI numbers mean
| AQI | Category | What it means for you |
|---|---|---|
| 0–50 | Good | Open the windows. Great for outdoor activity. |
| 51–100 | Moderate | Sensitive groups may want to take it slower outside. |
| 101–150 | Unhealthy for Sensitive Groups | Kids, elderly, and respiratory conditions stay closer to home. |
| 151–200 | Unhealthy | Skip outdoor exercise. Close windows. |
| 201–300 | Very Unhealthy | Limit time outside. N95 if you must go. |
| 301+ | Hazardous | Health emergency. Stay inside, run filtration if you have it. |
Canairy lets you tighten these bands if you’re more sensitive than the EPA default, so an alert can fire before the official category changes. How to read the Air Quality Index
Where these readings come from
The AQI at the top of this page is the median of the 5 curated PurpleAir sensors Canairy tracks in and around Ottawa, with outliers set aside so that one sensor brought indoors — or parked beside a barbecue — cannot set the number for a whole city. Every sensor behind it is listed above with its distance and bearing from the city center. There is no black box here.
In the app, a place you save resolves the same way first. When no neighborhood sensor is reporting it falls back to the nearest EPA AirNow monitor, and anything modeled rather than measured is labelled a regional estimate rather than passed off as a sensor reading. How low-cost sensors compare to regulatory monitors
About Canairy
Canairy is free to download. The free plan covers one saved place with live readings, a plain-English verdict, and push alerts when the air crosses a threshold you choose. Paid plans add more places, faster refreshes, and SMS alerts. It is built by two parents in Sonoma County, California, who got tired of guessing whether it was safe to send the kids outside. Why we built it
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Air quality near Ottawa
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