Photo: Veillg1 · CC BY-SA 4.0Flood mapping exists for McMasterville: 1 on record, latest by Gouvernement du Québec
Burn scars are few around McMasterville, with 0.1% of the land within 25 km touched by fire since 1986 (0.002% a year). Shaking is a bigger worry than in most places, at $0.18 a year per $1,000 of building value ($0.030 typical). Radon around McMasterville is ordinary for Canada: 8.2% of tested homes over the guideline (6.6% typical). McMasterville grades C− for hazard risk; wildfire is low here, so it earns no credit.
What stands out about McMasterville’s hazards
Four national sources, each read for McMasterville: earthquakes, radon, past fires and flood studies.
What McMasterville faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
McMasterville grades C− for hazard risk
The grade weighs McMasterville’s seismic risk and radon equally, and wildfire is one-sided: a high band counts against a town, a low one earns nothing.
Its place: #339 of 507 in Quebec and #2,305 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Small fires and grass fires are largely missing from the national burned-area record.
Little of the land around McMasterville has burned: 0% within 5 km, 0.1% within 25 km since 1986
Past fire around McMasterville’s homes, from the national burned-area record, with the fuel within 5 km.
In a typical year 0.002% of the land near McMasterville burns; the typical Canadian town sees 0.000%, and both are low.
Fire has stayed at least 6.6 km from McMasterville’s homes since 1986.
Only 1.4% of the land within 25 km of McMasterville is forest fuel, and 0.5% close in.
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
The land around McMasterville burns at 0.002% a year, the 35th highest rate of 513 towns in Quebec; Mistissini tops it 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; McMasterville 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.
Gouvernement du Québec has mapped flooding for McMasterville (1 study)
What Canada’s Flood Map Inventory lists for McMasterville: who studied flooding and where to see their maps.
The flood study touching McMasterville is Gouvernement du Québec’s, dated 1979; its own map shows the zones street by street.
| Study | By | Year | Status |
|---|---|---|---|
| Sorel-Chambly | Gouvernement du Québec | 1979 | final |
Towns with a flood study on file
Mapping in Quebec reaches 45% of towns, McMasterville among them, below the 58% across Canada.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Nothing here counts toward Risk; the studies are pointers to the maps their owners keep for McMasterville.
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.
Earthquakes cost buildings in McMasterville $0.18 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; McMasterville loses $0.18, 6.1 times as much.
Shaking damage a year per $1,000 of building value
Above the middle in Quebec: McMasterville’s $0.18 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.
More earthquake risk than most: only 13% of Canada’s 2,611 towns are above McMasterville.
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).
The model counts damage to McMasterville’s buildings and their occupants from shaking only: not liquefaction, landslides, tsunami or fires after a quake.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Some radon around McMasterville: 8.2% of area homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
Around McMasterville, 8.2% of tested homes topped the guideline, near the typical Canadian town’s 6.6%. For radon tests, the only official count covers all of the Monteregie health region, McMasterville included.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
McMasterville’s 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 McMasterville 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.
One home in McMasterville 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 McMasterville
Environment and Climate Change Canada issues the weather alerts for McMasterville; 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 McMasterville come through Environment Canada and Alert Ready; the fire map is CWFIS’s.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around McMasterville
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| McMasterville | Low | $0.18 | 8.2% | Yes |
| Otterburn Park 9,460 · 2.8 km | Low | $0.13 | 8.2% | Yes |
| Beloeil 25,240 · 3.2 km | Low | $0.20 | 8.2% | Yes |
| Mont-Saint-Hilaire 19,447 · 4.1 km | Low | $0.12 | 8.2% | Yes |
| Saint-Basile-le-Grand 17,146 · 5.2 km | Low | $0.18 | 8.2% | Yes |
| Saint-Mathieu-de-Beloeil 2,999 · 5.3 km | Low | $0.15 | 8.2% | Yes |
| Saint-Mathias-sur-Richelieu 4,598 · 8.1 km | Low | $0.18 | 8.2% | Yes |
McMasterville’s low band tops its neighbours; Otterburn Park is next (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what McMasterville faces
What to do about the hazards McMasterville 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
- 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 McMasterville.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; McMasterville’s figure is its subdivision’s.
- Wildfire counts one way. Wildfire is read from the national burned-area record around McMasterville’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for McMasterville is its health region’s, the survey’s design unit.
Questions about flooding and hazards in McMasterville
How is McMasterville’s Hazard risk Grade worked out?
McMasterville’s Hazard risk grade is C−, built on earthquakes and radon with a one-sided wildfire input.
Is McMasterville at risk of wildfire?
Fire has reached 0.1% of the land around McMasterville since 1986 (last in 2024); at low, it neither helps nor hurts the grade.
Is radon a problem in McMasterville?
Around McMasterville, 110 survey homes were tested and 8.2% came in over 200 Bq/m³, a guide to the area, not to any one home.
How big is the earthquake risk in McMasterville?
NRCan’s model expects shaking to cost buildings in McMasterville $0.18 a year for every $1,000 of their value, on average over many years.
Does McMasterville flood?
There is flood mapping for McMasterville on the national inventory, each study linked to its owner’s map, none of them graded.
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).