Photo: P199 · CC BY-SA 4.0Les Cèdres’ hazards at a glance: a low wildfire record and 8.2% of area homes over the radon guideline
Wildfire isn’t Les Cèdres’ worry: 0% of the land within 25 km burned since 1986 (0.001% a year). Shaking is a bigger worry than in most places, at $0.15 a year per $1,000 of building value ($0.030 typical). Hazard risk gives Les Cèdres a grade of C, from earthquakes and radon alone.
What stands out about Les Cèdres’s hazards
For Les Cèdres, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Les Cèdres faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Les Cèdres grades C for hazard risk
Two inputs always count for Les Cèdres, earthquakes and radon; the third, wildfire, counts only against a town.
Its place: #264 of 507 in Quebec and #2,217 of 2,589 Canadian towns.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Wildfire is rare near Les Cèdres: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Les Cèdres’ residents live, and the fuel next to their homes.
A burn rate of 0.001% a year keeps Les Cèdres in the low band (the typical Canadian town: 0.000%).
The closest burn since 1986 lies 9.0 km from Les Cèdres’ homes, none within 5 km.
Forest fuel is scarce around Les Cèdres: 3.1% of the land within 5 km, 2.4% 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
Les Cèdres burns at 0.001% a year, 136th of 513 towns in Quebec; the leader, Mistissini, reaches 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.
7.5% of Canada’s 2,610 towns burn fast enough to rank moderate or above; Les Cèdres 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 Les Cèdres
Flood studies whose area touches Les Cèdres, from NRCan’s inventory, each linked to its owner.
NRCan’s inventory is silent on Les Cèdres, so any flood map would be the municipality’s own.
Towns with a flood study on file
No study touches Les Cèdres; 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 Les Cèdres 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 Les Cèdres: $0.15 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 $0.15 per $1,000, Les Cèdres carries roughly 4.9 times the typical Canadian town’s earthquake risk ($0.030).
Shaking damage a year per $1,000 of building value
About level with the typical town in Quebec: Les Cèdres’ $0.15 against $0.14; 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.
In the upper part of Canada’s range: 19% of its 2,611 towns expect more damage than Les Cèdres.
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).
Only shaking damage to buildings in Les Cèdres is counted; landslides, liquefaction, tsunami and fire after a quake aren’t.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
8.2% of homes tested around Les Cèdres are over the radon guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · The radon tests numbers here cover the Monteregie health region
Les Cèdres’ area sits close to the typical Canadian town: 8.2% over the guideline, against 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Les Cèdres’ area, at 8.2%, is close to the median in Quebec (8.2%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
A middling share of high tests puts Les Cèdres with 37% of Canada’s 2,611 towns, below 26% of them.
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.
Health Canada advises testing every home, Les Cèdres’ included, whatever the area’s figure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Les Cèdres
Alerts for Les Cèdres 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 Les Cèdres to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Les Cèdres’ neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Les Cèdres | Low | $0.15 | 8.2% | None listed |
| Pointe-des-Cascades 1,867 · 7.1 km | Low | $0.14 | 8.2% | Yes |
| Vaudreuil-Dorion 46,413 · 8.3 km | Low | $0.17 | 8.2% | Yes |
| Salaberry-de-Valleyfield 47,002 · 8.3 km | Low | $0.19 | 8.2% | None listed |
| Pincourt 15,220 · 8.7 km | Low | $0.17 | 8.2% | Yes |
| Coteau-du-Lac 7,839 · 8.9 km | Low | $0.14 | 8.2% | None listed |
| Terrasse-Vaudreuil 1,883 · 9.4 km | Low | $0.19 | 8.2% | Yes |
Fire is no heavier anywhere nearby than around Les Cèdres (low), with Pointe-des-Cascades next at low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Les Cèdres faces
What to do about the hazards Les Cèdres 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
- Wildfire counts one way. For Les Cèdres, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Les Cèdres’ census subdivision (a neighbourhood shows its city’s).
- Radon is a survey. Radon figures pool the survey’s home tests by area: postal areas once their boundaries arrive, the 2007 health region around Les Cèdres until then.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Les Cèdres without grading them.
Questions about flooding and hazards in Les Cèdres
Does Les Cèdres flood?
Nothing is listed for Les Cèdres on the national inventory (0); local maps may still exist with the municipality.
How is Les Cèdres’s Hazard risk Grade worked out?
Les Cèdres’ Hazard risk grade is C, built on earthquakes and radon with a one-sided wildfire input.
How big is the earthquake risk in Les Cèdres?
Expected earthquake damage in Les Cèdres comes to $0.15 a year for each $1,000 that buildings are worth.
Is radon a problem in Les Cèdres?
In Health Canada’s survey, 8.2% of 110 homes tested in Les Cèdres’ area were above 200 Bq/m³, though only a test tells you about one house.
Is Les Cèdres at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Les Cèdres has burned since 1986, the last in 2025, a low band that leaves Risk alone.
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).