Photo: P199 · CC BY-SA 4.0Wildfire low, radon 10%: how Mille-Isles stands on hazards
Little of the land around Mille-Isles has burned: 0.1% within 25 km since 1986, or 0.002% a year. Earthquakes add more: NRCan’s model puts building losses at $0.10 a year per $1,000 of value, against $0.030 for the typical town. Hazard risk gives Mille-Isles a grade of C−, from earthquakes and radon alone.
What stands out about Mille-Isles’s hazards
For Mille-Isles, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Mille-Isles faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Mille-Isles grades C− for hazard risk
Two inputs always count for Mille-Isles, earthquakes and radon; the third, wildfire, counts only against a town.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. Only 78 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 Mille-Isles: 0% within 5 km, 0.1% within 25 km
Fires mapped since 1986 around where Mille-Isles’ residents live, and the fuel next to their homes.
Around Mille-Isles fire takes 0.002% of the land in a typical year, the typical Canadian town 0.000%, which is low.
More forest grows near Mille-Isles’ homes (41% within 5 km) than across 25 km (21%).
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 514
In the top quarter in Quebec: Mille-Isles ranks 35th of 514 at 0.002% a year, with Mistissini first 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.
Some fire is mapped around Mille-Isles, 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.
The flood map inventory lists nothing for Mille-Isles
Flood studies whose area touches Mille-Isles, from NRCan’s inventory, each linked to its owner.
No flood study on the national inventory covers Mille-Isles; ask the municipality, which is the authority for its flood maps.
Towns with a flood study on file
No study touches Mille-Isles; in Quebec, 45% of towns have one, below Canada’s 58%.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Listed, not scored: a flood study proves a map exists, not that Mille-Isles floods.
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 Mille-Isles: $0.10 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.
The typical town loses $0.030 a year to shaking; Mille-Isles loses $0.10, 3.4 times as much.
Shaking damage a year per $1,000 of building value
The typical town in Quebec expects $0.14 a year in shaking damage; Mille-Isles expects less, $0.10, and La Pocatière the most, $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.
26% of Canada’s 2,611 towns expect more shaking damage than Mille-Isles, which places it in the upper third.
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 Mille-Isles.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Test for radon in Mille-Isles: 10% of area homes were over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Measured across the Laurentides health region: radon tests
More homes than usual test high around Mille-Isles: 10% against 6.6% for the typical Canadian town.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Mille-Isles’ area, at 10%, is above the median in Quebec (8.2%), and 1.3% of its tests passed 600 Bq/m³.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Mille-Isles 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.
Radon varies from house to house in Mille-Isles, so the survey is a reason to test, not a result for yours.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Mille-Isles
Alerts for Mille-Isles 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 Mille-Isles to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Mille-Isles’ neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Mille-Isles | Low | $0.10 | 10% | None listed |
| Morin-Heights 5,086 · 7.7 km | Low | $0.069 | 10% | None listed |
| Saint-Sauveur 12,112 · 7.9 km | Low | $0.094 | 10% | None listed |
| Sainte-Anne-des-Lacs 4,080 · 8.9 km | Low | $0.10 | 10% | None listed |
| Gore 2,756 · 9.1 km | Low | $0.097 | 10% | None listed |
| Piedmont 3,667 · 10 km | Low | $0.072 | 10% | None listed |
| Prévost 14,275 · 13 km | Low | $0.088 | 10% | Yes |
None of the places around has more fire nearby than Mille-Isles (low); Morin-Heights comes closest (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Mille-Isles faces
What to do about the hazards Mille-Isles 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 Mille-Isles sits in.
- Wildfire counts one way. For Mille-Isles, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- 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 Mille-Isles floods.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Mille-Isles’ census subdivision (a neighbourhood shows its city’s).
Questions about flooding and hazards in Mille-Isles
How is Mille-Isles’s Hazard risk Grade worked out?
Mille-Isles’ Hazard risk grade is C−, built on earthquakes and radon with a one-sided wildfire input.
How big is the earthquake risk in Mille-Isles?
About $0.10 a year per $1,000 of building value, NRCan’s long-run expectation for Mille-Isles.
Does Mille-Isles flood?
With 0 studies on the inventory, Mille-Isles’ flood risk is unmapped nationally; check with the municipality before buying.
Is Mille-Isles at risk of wildfire?
Fire has reached 0.1% of the land around Mille-Isles since 1986 (last in 2025); at low, it neither helps nor hurts the grade.
Is radon a problem in Mille-Isles?
Around Mille-Isles, 78 survey homes were tested and 10% 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).