Photo: Robbie Sproule from Montreal, Canada · CC BY 2.0Hazards in Montréal-Ouest: wildfire low, radon over the guideline in 6.8% of tested homes
Little of the land around Montréal-Ouest has burned: 0.1% within 25 km since 1986, or 0.001% a year. Shaking is a bigger worry than in most places, at $0.19 a year per $1,000 of building value ($0.030 typical). Montréal-Ouest grades C for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Montréal-Ouest’s hazards
For Montréal-Ouest, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Montréal-Ouest faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Montréal-Ouest grades C for hazard risk
Two inputs always count for Montréal-Ouest, earthquakes and radon; the third, wildfire, counts only against a town.
Its place: #148 of 507 in Quebec and #2,095 of 2,589 Canadian towns.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. Only 74 homes were tested in the survey area, so the radon share is rough. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Few fires near Montréal-Ouest: 0% within 5 km, 0.1% within 25 km
Fires mapped since 1986 around where Montréal-Ouest’s residents live, and the fuel next to their homes.
Low: the land around Montréal-Ouest burns at 0.001% a year, where the typical Canadian town sees 0.000%.
The closest burn since 1986 lies 5.9 km from Montréal-Ouest’s homes, none within 5 km.
Little near Montréal-Ouest’s homes can carry a forest fire; only 0.1% of the land within 5 km is forest fuel, and 0.5% within 25 km.
Shares of land within 5 and 25 km of populated blocks: burned at least once in 1986–2025 (CWFIS burned-area composite), forest fuel and grass (fire behaviour fuel types, 2026, 250 m grid).
Burn rate a year, towns in Quebec · highest of 513
At 0.001% a year, Montréal-Ouest ranks 136th of the 513 towns in Quebec; Mistissini leads at 0.31%.
Each bar: the yearly average share of land within 25 km of a town’s homes that burned, 1986–2025 (CWFIS); the seven highest towns of 2,500 people or more.
Beside 2,610 Canadian towns, Montréal-Ouest reads low, with 92% of them; only 7.5% rank higher.
Bands of the yearly burn rate: low under 0.05%, moderate under 0.25%, high under 1%, very high 1% or more; towns of 2,500 people or more.
Fire danger and active fires (CWFIS)
Canadian Wildland Fire Information System: National Burned Area Composite 1986–2025 and fire behaviour fuel types (2026), Natural Resources Canada. Measured within 25 km and 5 km of each populated dissemination area; past fire, not a forecast.
The flood map inventory lists nothing for Montréal-Ouest
Flood studies whose area touches Montréal-Ouest, from NRCan’s inventory, each linked to its owner.
Canada’s Flood Map Inventory lists no study whose area touches Montréal-Ouest, which doesn’t mean it has never been mapped.
Towns with a flood study on file
Mapping in Quebec reaches 45% of towns, below the 58% across Canada, and not Montréal-Ouest.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood studies don’t enter the grade; they are listed so you can open the official map for Montréal-Ouest.
The inventory’s own caution (NRCan): “The Canada Flood Map (CFM) does not include every flood hazard map in Canada and may be incomplete or contain inaccuracies. It should not be relied upon as the official source of flood mapping information. Furthermore, if a map appears to be missing, this does not necessarily mean that the area has never been mapped. For the official version of a map, updated information, or confirmation of applicable regulations, please contact the local authority responsible for flood mapping.”
Shaking is Montréal-Ouest’s costliest hazard: $0.19 a year per $1,000
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
The typical town loses $0.030 a year to shaking; Montréal-Ouest loses $0.19, 6.4 times as much.
Shaking damage a year per $1,000 of building value
Montréal-Ouest’s $0.19 tops the median in Quebec, $0.14, though La Pocatière reaches $0.48.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Montréal-Ouest sits above most of Canada’s 2,611 towns on earthquake risk; 12% are higher.
Each column: the share of Canada’s towns of 2,500 people or more in that range of yearly loss per $1,000 (NRCan, 2022).
For Montréal-Ouest the model prices shaking damage to buildings, nothing more.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Radon about average around Montréal-Ouest: 6.8% over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
Around Montréal-Ouest, 6.8% of tested homes topped the guideline, near the typical Canadian town’s 6.6%. Behind radon tests sits data gathered across the Montreal health region, with Montréal-Ouest one part of it.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon around Montréal-Ouest is ordinary for towns in Quebec: 6.8%, beside a median of 8.2%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Montréal-Ouest is in the 5–10% band with 37% of Canada’s 2,611 towns; 26% have more.
Each bar: the share of Canada’s towns of 2,500 people or more whose survey area had that share of tests over 200 Bq/m³.
Whatever Montréal-Ouest’s area share, the reading that matters is your own home’s, over a winter.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Montréal-Ouest
Alerts for Montréal-Ouest come from Environment and Climate Change Canada and, for emergencies, Alert Ready.
| Alert | What it means |
|---|---|
| Warning | Severe weather is happening or about to: act now. |
| Watch | Conditions favour severe weather: be ready. |
| Advisory | Weather that is less severe but could disrupt the day. |
| Special weather statement | Unusual weather worth knowing about. |
| Special air quality statement | Poor air, often wildfire smoke. |
Fire danger and active fires near Montréal-Ouest are mapped daily by the Canadian Wildland Fire Information System; evacuation orders come from the municipality or province.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Montréal-Ouest
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Montréal-Ouest | Low | $0.19 | 6.8% | None listed |
| Loyola 26,607 · 1.4 km | Low | $0.20 | 6.8% | None listed |
| Côte-Saint-Luc 37,901 · 2.2 km | Low | $0.23 | 6.8% | None listed |
| Vieux-Lachine - Saint-Pierre 31,113 · 2.3 km | Low | $0.20 | 6.8% | None listed |
| Upper Lachine 21,130 · 2.7 km | Low | $0.20 | 6.8% | None listed |
| Cecil-P.-Newman 34,965 · 2.7 km | Low | $0.20 | 6.8% | None listed |
| Hampstead 7,464 · 3.0 km | Low | $0.22 | 6.8% | None listed |
Loyola (low) has the heaviest fire record of Montréal-Ouest’s neighbours, and Montréal-Ouest (low) matches or beats it.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Montréal-Ouest faces
What to do about the hazards Montréal-Ouest faces, and what to ask before you buy.
- Test for three months in winter.
- Over 200 Bq/m³: fix it.
- Kits are cheap; pros test too.
- Never drive through floodwater.
- Move papers and medicines upstairs.
- Ask whether your street is mapped.
- Drop, cover and hold on.
- Strap the water heater down.
- Keep 72 hours of supplies.
- Has it had a radon test?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
- Is earthquake cover included?
What this data can and can’t tell you
- Radon is a survey. The radon share comes from about 14,000 long-term home tests in 2009–2011, pooled for now by the 2007 health region Montréal-Ouest sits in.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Montréal-Ouest’s included.
- Flood studies aren’t flood zones. A study’s area can be a whole watershed or province, so being on the inventory says a map exists, not that a home in Montréal-Ouest floods.
- Wildfire counts one way. Burned land within 25 km of where people live, averaged over 1986–2025 and checked for fuel near homes, is the measure; it looks back, not ahead, and only ever counts against Montréal-Ouest.
Questions about flooding and hazards in Montréal-Ouest
Is Montréal-Ouest at risk of wildfire?
Fire has reached 0.1% of the land around Montréal-Ouest since 1986 (last in 2025); at low, it neither helps nor hurts the grade.
How big is the earthquake risk in Montréal-Ouest?
About $0.19 a year per $1,000 of building value, NRCan’s long-run expectation for Montréal-Ouest.
Does Montréal-Ouest flood?
With 0 studies on the inventory, Montréal-Ouest’s flood risk is unmapped nationally; check with the municipality before buying.
How is Montréal-Ouest’s Hazard risk Grade worked out?
Montréal-Ouest’s Hazard risk grade is C, built on earthquakes and radon with a one-sided wildfire input.
Is radon a problem in Montréal-Ouest?
Around Montréal-Ouest, 74 survey homes were tested and 6.8% came in over 200 Bq/m³, a guide to the area, not to any one home.
Seismic risk: Natural Resources Canada. Radon: Health Canada. Wildfire: Canadian Wildland Fire Information System. Flood studies: Natural Resources Canada, Canada Flood Map Inventory. Contains information licensed under the Open Government Licence – Canada.
Sources: NRCan, Canada’s Seismic Risk Model 2022 · Health Canada, Cross-Canada Survey of Radon Concentrations in Homes · CWFIS, National Burned Area Composite and FBP fuel types · NRCan, Canada Flood Map Inventory. Under the Statistics Canada Open Licence.
Adapted from Statistics Canada (Census of Population 2021, population estimates 2025, 2021 census boundaries) under the Statistics Canada Open Licence; this does not constitute an endorsement by Statistics Canada. Neighbourhood names in some cities © OpenStreetMap contributors (ODbL).