Photo: P199 · CC BY-SA 3.0Hazard risk in Mirabel is higher than in 85% of Canadian towns
Wildfire is rare near Mirabel: 0% of the land within 25 km has burned since 1986, a burn rate of 0.001% a year. Seismic risk runs high: $0.16 of expected damage per $1,000 of buildings a year, the typical town $0.030. More homes than usual carry radon here, 10% over the guideline where the typical town has 6.6%. Hazard risk gives Mirabel a grade of D, from earthquakes and radon alone.
What stands out about Mirabel’s hazards
Four national sources, each read for Mirabel: earthquakes, radon, past fires and flood studies.
What Mirabel faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Mirabel: D
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Mirabel with little fire nearby would get no credit for it.
Its place: #427 of 507 in Quebec and #2,419 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Only 78 homes were tested in the survey area, so the radon share is rough. Small fires and grass fires are largely missing from the national burned-area record.
Few fires near Mirabel: 0% within 5 km, 0% within 25 km
Fires mapped since 1986 around where Mirabel’s residents live, and the fuel next to their homes.
Next to the typical Canadian town (0.000% a year), Mirabel’s 0.001% is in the low band.
About as much forest grows next to Mirabel’s homes (6.4% within 5 km) as across 25 km (11%).
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%): Mirabel 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.
Some fire is mapped around Mirabel, but not enough to leave the low band, where 92% of Canada’s 2,610 towns are; 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.
A flood study covers Mirabel, from Gouvernement du Québec: 1 on the inventory
Flood studies whose area touches Mirabel, from NRCan’s inventory, each linked to its owner.
A 1992 study by Gouvernement du Québec covers Mirabel, and its map, not the inventory, shows the zones.
| Study | By | Year | Status |
|---|---|---|---|
| Lachute-St-Jérôme | Gouvernement du Québec | 1992 | final |
Towns with a flood study on file
Flood maps are thinner in Quebec, 45% of towns against 58% nationally, but Mirabel has one.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood is shown here, never graded: a study says where a map exists, not how many of Mirabel’s homes stand in a flood zone.
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.”
Natural Resources Canada, Canada Flood Map Inventory; links go to each study’s owner.
High seismic risk in Mirabel: $0.16 per $1,000 of buildings a year
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
At $0.16 per $1,000, Mirabel carries roughly 5.3 times the typical Canadian town’s earthquake risk ($0.030).
Shaking damage a year per $1,000 of building value
Neither high nor low in Quebec: Mirabel’s $0.16 sits by the median of $0.14, while 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.
Mirabel sits above most of Canada’s 2,611 towns on earthquake risk; 15% 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).
Roads, pipes and bridges aren’t in Mirabel’s figure, nor landslides or tsunami: it is buildings and shaking.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Radon runs high around Mirabel: 10% of tested homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
A higher share than most: 10% of tested homes around Mirabel, the typical Canadian town 6.6%. For radon tests, the only official count covers all of the Laurentides health region, Mirabel included.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
More homes top the guideline around Mirabel (10%) than in the typical town in Quebec (8.2%); 1.3% went over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Mirabel is in the 10–20% band, with 22% of Canada’s 2,611 towns; only 4.6% 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.
One home in Mirabel can be high while next door is low; a three-month test settles it.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Mirabel
Environment and Climate Change Canada issues the weather alerts for Mirabel; Alert Ready carries the urgent ones to phones, radio and TV.
| 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. |
For fires near Mirabel, the national fire information system maps danger and active fires daily; local authorities give any evacuation order.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Mirabel’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Mirabel | Low | $0.16 | 10% | Yes |
| Blainville 61,739 · 5.7 km | Low | $0.19 | 10% | None listed |
| Sainte-Thérèse 27,253 · 8.1 km | Low | $0.20 | 10% | None listed |
| Boisbriand 29,830 · 9.4 km | Low | $0.20 | 10% | Yes |
| Saint-Eustache 47,562 · 11 km | Low | $0.20 | 10% | Yes |
| Rosemère 14,198 · 12 km | Low | $0.16 | 10% | Yes |
| Lorraine 9,721 · 12 km | Low | $0.18 | 10% | Yes |
Fire is no heavier anywhere nearby than around Mirabel (low), with Blainville next at low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Mirabel faces
What to do about the hazards Mirabel 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?
- Check the address on the flood map.
- Are flood and wildfire insured?
- Is earthquake cover included?
What this data can and can’t tell you
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Mirabel is its health region’s, the survey’s design unit.
- Flood studies aren’t flood zones. NRCan’s inventory says where flood mapping exists, not where water goes; the map’s owner is the authority for Mirabel.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Mirabel’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Mirabel’s figure is its subdivision’s.
Questions about flooding and hazards in Mirabel
How is Mirabel’s Hazard risk Grade worked out?
Mirabel’s Hazard risk grade is D, built on earthquakes and radon with a one-sided wildfire input.
How big is the earthquake risk in Mirabel?
About $0.16 a year per $1,000 of building value, NRCan’s long-run expectation for Mirabel.
Is Mirabel at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Mirabel has burned since 1986, the last in 2025, a low band that leaves Risk alone.
Does Mirabel flood?
There is flood mapping for Mirabel on the national inventory, each study linked to its owner’s map, none of them graded.
Is radon a problem in Mirabel?
In Health Canada’s survey, 10% of 78 homes tested in Mirabel’s area were above 200 Bq/m³, though only a test tells you about one house.
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).