Photo: Pymouss · CC BY-SA 4.0Wildfire low, radon 6.8%: how Dorval stands on hazards
Wildfire is rare near Dorval: 0.1% of the land within 25 km has burned since 1986, a burn rate of 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). Hazard risk gives Dorval a grade of C, from earthquakes and radon alone.
What stands out about Dorval’s hazards
For Dorval, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Dorval faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Dorval: C
Seismic risk and radon set Dorval’s grade, wildfire can drag it down, and flood mapping stays out of it.
Its place: #144 of 507 in Quebec and #2,090 of 2,589 Canadian towns.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. The radon share rests on 74 home tests in the survey area, so a few homes move it. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Wildfire is rare near Dorval: 0.1% of the land within 25 km burned since 1986, 0% within 5 km
Past fire around Dorval’s homes, from the national burned-area record, with the fuel within 5 km.
The yearly burn rate around Dorval is 0.001%, low beside 0.000% for the typical Canadian town.
The 5 km ring around Dorval’s homes is clear of burns since 1986, the nearest 7.2 km out.
Forest makes up 0.6% of the land within 5 km of Dorval and 0.9% within 25 km, little for a forest fire to run through.
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
In the upper half in Quebec but far from Mistissini (0.31%): Dorval ranks 136th of 513, at 0.001% a year.
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.
7.5% of Canada’s 2,610 towns burn fast enough to rank moderate or above; Dorval stays low, with 92%.
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 Dorval
What Canada’s Flood Map Inventory lists for Dorval: who studied flooding and where to see their maps.
Nationally, Dorval has no listed flood study; the municipality is the place to ask.
Towns with a flood study on file
Mapping in Quebec reaches 45% of towns, below the 58% across Canada, and not Dorval.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood mapping is shown for Dorval to be opened and checked, never turned into a grade.
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.”
High seismic risk in Dorval: $0.19 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Dorval’s $0.19 is about 6.2 times the typical town’s $0.030: it sits in one of Canada’s more active seismic zones.
Shaking damage a year per $1,000 of building value
Above the middle in Quebec: Dorval’s $0.19 against a median of $0.14, with La Pocatière highest at $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.
Dorval sits above most of Canada’s 2,611 towns on earthquake risk; 13% 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).
What a quake does after the shaking, fire, landslides, tsunami, falls outside NRCan’s figure for Dorval.
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 Dorval: 6.8% over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · The radon tests numbers here cover the Montreal health region
Dorval’s area, at 6.8%, is close to the 6.6% of the typical Canadian town.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
The typical town in Quebec has 8.2% over 200 Bq/m³; Dorval’s area has 6.8%, much the same.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Between 5% and 10% of tests over the guideline: Dorval, and 37% of Canada’s 2,611 towns; 26% are higher.
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.
Neighbouring homes in Dorval can differ a lot; only a long-term test tells you about yours.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Dorval
Alerts for Dorval 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. |
Alert Ready carries evacuation orders for Dorval to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Dorval’s neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Dorval | Low | $0.19 | 6.8% | None listed |
| Lachine-Ouest 15,315 · 3.8 km | Low | $0.20 | 6.8% | None listed |
| Pointe-Claire 37,437 · 4.9 km | Low | $0.19 | 6.8% | Yes |
| Vieux-Lachine - Saint-Pierre 31,113 · 6.1 km | Low | $0.20 | 6.8% | None listed |
| Dollard-Des Ormeaux 50,246 · 6.9 km | Low | $0.23 | 6.8% | None listed |
| Côte-Saint-Luc 37,901 · 7.4 km | Low | $0.23 | 6.8% | None listed |
| Bois-Francs 35,858 · 7.6 km | Low | $0.20 | 6.8% | None listed |
Dorval’s low band tops its neighbours; Lachine-Ouest is next (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Dorval faces
Practical steps for Dorval’s hazards, most pressing first.
- 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 Dorval sits in.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Dorval’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 Dorval 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 Dorval.
Questions about flooding and hazards in Dorval
Is Dorval at risk of wildfire?
Not much by Canadian standards: Dorval’s band is low, with 0.1% of the land within 25 km burned since 1986 (last in 2025), so wildfire doesn’t change its grade.
Is radon a problem in Dorval?
6.8% of the 74 homes Health Canada tested around Dorval topped the guideline; your own house needs its own test.
How is Dorval’s Hazard risk Grade worked out?
Dorval’s Hazard risk grade is C, built on earthquakes and radon with a one-sided wildfire input.
How big is the earthquake risk in Dorval?
NRCan’s model expects shaking to cost buildings in Dorval $0.19 a year for every $1,000 of their value, on average over many years.
Does Dorval flood?
No study on Canada’s Flood Map Inventory covers Dorval (0), which doesn’t mean it has never been mapped, so ask the municipality.
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).