Air quality comparison · Canada, 503 km apart
Montréal vs Toronto Air quality index (AQI) today
Montréal has cleaner air than Toronto right now: AQI 17 (Good) against 60 (Moderate).
That puts them in different EPA bands, so the health advice differs today. But over the past 7 days, on modeled daily averages, Toronto averaged AQI 27 against 36, and it was the cleaner of the two on 5 of those days. Montréal has lost more forest since 2001. Montréal has more tree cover.
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Montréal17Toronto60
Head to head
Montréal vs Toronto at a glance
Montréal is ahead on 4 of 6 measures, and Toronto on 2. The better figure in each row is marked.
| Montréal | Toronto | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 17 (better) | 60 |
| PM2.5Fine particles, µg/m³. | 2.3 (better) | 14 |
| Past week's averageUS AQI, 7 days. | 36 | 27 (better) |
| Forest lost since 2001Within 10 km of the center. | 23 ha | 16 ha (better) |
| Tree coverWithin 2 km of the center. | 44.4% (better) | 15.6% |
| Trees still neededTo reach a healthy canopy. | 0 (better) | 42.5K |
Air quality today
What is the air like in Montréal and Toronto right now?
Montréal has cleaner air than Toronto right now: AQI 17 (Good) against 60 (Moderate). Ozone is setting the index in Montréal, and PM2.5 in Toronto.
Both readings come from nearby ground stations.
MontréalToronto
Concentrations at the same moment as the index above, for the pollutants both places report. Lower is better. The dark marks on the PM2.5 and PM10 rows show the WHO's 24-hour guidelines (15 and 45 µg/m³).
The past week
Which had cleaner air over the past 7 days?
But over the past 7 days, on modeled daily averages, Toronto averaged AQI 27 against 36, and it was the cleaner of the two on 5 of those days. A single reading can catch a city on a bad afternoon; the week says whether it was the weather or the place.
- Cleaner days
- Montréal2Toronto5
- Average AQI
- Montréal36Toronto27
- Worst day, AQI
- Montréal51Toronto35
The daily numbers (7 days)
| Day | Montréal | Toronto |
|---|---|---|
| Nov 5 | 33 | 27 |
| Nov 6 | 43 | 27 |
| Nov 7 | 45 | 33 |
| Nov 8 | 31 | 35 |
| Nov 9 | 38 | 11 |
| Nov 10 | 51 | 26 |
| Nov 11 | 9 | 28 |
Daily averages from the CAMS atmospheric model for both places, so the week compares like with like. They can differ from today's reading at the top of the page wherever that comes from a ground station.
What it means today
Is it safe to go outside in Montréal and Toronto today?
Montréal (AQI 17, Good): Air quality is satisfactory for everyone.
Toronto (AQI 60, Moderate): Unusually sensitive people should consider limiting long outdoor exertion.
Exercise outdoors
- Montréal
- A good day to be active outside.
- Toronto
- Fine for most people; unusually sensitive people should take long or hard exercise easier.
Windows
- Montréal
- Open them to air the house.
- Toronto
- Fine to open; close them if you are sensitive to pollution.
Masks
- Montréal
- Not needed.
- Toronto
- Not needed for most people.
Air purifier
- Montréal
- Not needed.
- Toronto
- Worth running if you are sensitive.
Against everywhere else
How do Montréal and Toronto compare with the rest of the world?
Right now Montréal's air is cleaner than 90% of the 5,420 places Airleaf tracks, and Toronto's is cleaner than 48%. Within Canada, that is 79% and 10% of its 59 measured places.
Cleaner air than…
- Montréal
- Beats 90%
- Toronto
- Beats 48%
More tree cover than…
- Montréal
- Beats 88%
- Toronto
- Beats 36%
Includes model estimates as well as station readings, so it can differ from our most polluted and cleanest air rankings, which use station readings only.
Deforestation · 2001–2025
Which has lost more forest, Montréal or Toronto?
Montréal has lost more: about 23 ha of forest within 10 km of its center from 2001 to 2025, against 16 ha around Toronto. 18 ha of that was cleared for good, for farms, mines or towns.
Measured within 10 km of each center, from the yearly satellite maps of forest loss: a wider circle than the one for tree cover, because forest is usually lost at a city's edges.
Worst year: 2004, with 5 ha lost.
Worst year: 2008, with 3 ha lost.
| Montréal | Toronto | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 23 ha | 16 ha (better) |
| Share of its forestOf what it had in 2000. | 1.4% | under 1% (better) |
| Cleared for goodTurned into farms, mines or towns. | 18 ha | 11 ha (better) |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Towns and roads (76%) | Towns and roads (67%) |
Satellite timelapses
Watch both change, year by year
A clear satellite photo a year of the land around each city. Press play, turn on the forest cleared since the first year, or drag the before and after.
Montréal
2017: satellite photo from September 2017 of a 5 × 5 km area in the city center.
Toronto
2017: satellite photo from August 2017 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Montréal or Toronto?
Montréal has more tree cover: 44.4% of the land within 2 km of its center against 15.6% around Toronto, or about 139,208 trees against 46,068.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Montréal | Toronto | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 139K (better) | 46.1K |
| Trees still neededTo reach the target. Fewer is better. | 0 (better) | 42.5K |
| CO₂ absorbed each yearBy the trees already standing. | 3.1M kg (better) | 1.0M kg |
Tree cover on the satellite image
The same 2 km radius around each center, with the tree cover the satellite found marked on it.
Reading these numbers
How this comparison is made
Air quality index
The US EPA index, computed from current pollutant concentrations: ground stations where a place has them nearby, and the CAMS atmospheric model everywhere else. It moves hour to hour, so it is a snapshot rather than a verdict on either place. The guideline marks are from the WHO's 2021 air quality guidelines.
Trees and forest
Tree cover is the share of ground under canopy within 2 km of each center, read from Sentinel-2 satellite imagery at 10 m detail. It measures that circle, not the whole municipality, which is what makes the two comparable. Forest loss comes from the University of Maryland's Global Forest Change maps.
More on the method on the About Airleaf page.
Frequently asked
Montréal vs Toronto: your questions answered
Is Montréal cleaner than Toronto?
On air quality, yes, right now: Montréal reads AQI 17 against 60, a gap of 43 points on the US EPA index. This is a live reading rather than an annual average, so it can reverse within a day. But over the past 7 days, on modeled daily averages, Toronto averaged AQI 27 against 36, and it was the cleaner of the two on 5 of those days.
Is it safe to exercise outdoors in Montréal and Toronto today?
In Montréal, at AQI 17: Air quality is satisfactory for everyone. In Toronto, at AQI 60: Unusually sensitive people should consider limiting long outdoor exertion.
Which has lost more forest, Montréal or Toronto?
Montréal has lost more: about 23 ha of forest within 10 km of its center from 2001 to 2025, against 16 ha around Toronto. 18 ha of that was cleared for good, for farms, mines or towns.
Which has more trees, Montréal or Toronto?
Montréal has more tree cover: 44.4% of the land within 2 km of its center against 15.6% around Toronto, or about 139,208 trees against 46,068. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Montréal and Toronto need?
Montréal needs about 0 more to reach its canopy target of 30%, and Toronto about 42,525 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Montréal and Toronto measured the same way?
The method is the same: the US EPA index for air, and Sentinel-2 satellite imagery at 10 m detail over an identical radius for trees. Both readings come from nearby ground stations. Nothing is adjusted for population, city limits or climate.
How often does the Montréal vs Toronto comparison update?
The air readings refresh about once an hour, and each reading's local time is shown at the top of the page. Tree cover comes from the latest clear satellite image of each area (Sep 11, 2026 and Aug 18, 2026), and the forest figures are published yearly.
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