Photo: Baelzvuv · CC BY-SA 4.0Chomedey faces more hazards than 93% of Canadian towns
Since 1986 almost nothing has burned near Chomedey: 0% of the land within 25 km, or 0.001% a year. Seismic risk runs high: $0.21 of expected damage per $1,000 of buildings a year, the typical town $0.030. In Health Canada’s survey, 12% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Hazard risk gives Chomedey a grade of D, from earthquakes and radon alone.
What stands out about Chomedey’s hazards
For Chomedey, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Chomedey faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Chomedey: D
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Chomedey with little fire nearby would get no credit for it.
Its place: #485 of 507 in Quebec and #2,507 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Few fires near Chomedey: 0% within 5 km, 0% within 25 km
Past fire around Chomedey’s homes, from the national burned-area record, with the fuel within 5 km.
Fire claims 0.001% of the land around Chomedey each year, a low band, with the typical Canadian town at 0.000%.
No fire has burned within 5 km of Chomedey’s homes since 1986; the nearest burn is 11 km away.
Around Chomedey the forest is thin or far off: 0.3% of the land within 5 km and 2.3% within 25 km is forest fuel.
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, Chomedey 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.
7.5% of Canada’s 2,610 towns burn fast enough to rank moderate or above; Chomedey 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.
No flood study is listed for Chomedey
What Canada’s Flood Map Inventory lists for Chomedey: who studied flooding and where to see their maps.
No flood study on the national inventory covers Chomedey; ask the municipality, which is the authority for its flood maps.
Towns with a flood study on file
Mapping in Quebec reaches 45% of towns, below the 58% across Canada, and not Chomedey.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
The grade leaves flood out, since a study area says nothing about how many of Chomedey’s homes are at risk.
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.”
Earthquakes cost buildings in Chomedey $0.21 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
The typical town loses $0.030 a year to shaking; Chomedey loses $0.21, 6.9 times as much.
Figures for earthquake risk are published for the city of Laval as a whole, not for Chomedey alone.
Shaking damage a year per $1,000 of building value
Earthquake risk in Quebec peaks in La Pocatière ($0.48); Chomedey, at $0.21, sits above the median of $0.14.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Few of Canada’s 2,611 towns face more earthquake damage than Chomedey: 7.9% of them.
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 Chomedey 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).
Radon runs high around Chomedey: 12% of tested homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
Chomedey’s area, at 12%, is above the 6.6% of the typical Canadian town, so testing is worth more here than most places. Chomedey doesn’t get its own radon tests figures; the ones here come from the Laval health region.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Chomedey, 12% of tests were over 200 Bq/m³ and 0.9% over 600, against a median of 8.2% in Quebec.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
One test in ten or more tops the guideline around Chomedey, as in 22% of Canada’s 2,611 towns; 4.6% go 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 Chomedey, 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 Chomedey
Environment and Climate Change Canada issues the weather alerts for Chomedey; 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. |
Smoke and fire warnings for Chomedey come through Environment Canada and Alert Ready; the fire map is CWFIS’s.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Chomedey’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 |
|---|---|---|---|---|
| Chomedey | Low | $0.21 | 12% | None listed |
| Le Boisé Champêtre 37,891 · 2.5 km | Low | $0.21 | 12% | None listed |
| Cartierville 24,617 · 2.9 km | Low | $0.20 | 6.8% | None listed |
| Laval-des-Rapides 41,971 · 3.1 km | Low | $0.21 | 12% | None listed |
| Nouveau-Bordeaux 30,171 · 4.5 km | Low | $0.20 | 6.8% | None listed |
| Grenet 12,580 · 4.8 km | Low | $0.20 | 6.8% | None listed |
| Bois-Francs 35,858 · 4.9 km | Low | $0.20 | 6.8% | None listed |
Nowhere around Chomedey burns more: Le Boisé Champêtre, the closest rival, is low to its low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Chomedey faces
What to do about the hazards Chomedey 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. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Chomedey takes its 2007 health region’s share.
- Flood studies aren’t flood zones. The flood inventory points to maps; it is incomplete and not the official source, so ask the municipality about any street in Chomedey.
- 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 Chomedey.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Chomedey’s included.
Questions about flooding and hazards in Chomedey
Does Chomedey flood?
With 0 studies on the inventory, Chomedey’s flood risk is unmapped nationally; check with the municipality before buying.
How big is the earthquake risk in Chomedey?
NRCan’s model expects shaking to cost buildings in Chomedey $0.21 a year for every $1,000 of their value, on average over many years.
How is Chomedey’s Hazard risk Grade worked out?
Chomedey’s Hazard risk grade is D, built on earthquakes and radon with a one-sided wildfire input.
Is Chomedey at risk of wildfire?
Fire has reached 0% of the land around Chomedey since 1986 (last in 2025); at low, it neither helps nor hurts the grade.
Is radon a problem in Chomedey?
Around Chomedey, 107 survey homes were tested and 12% 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).