Photo: ShmushmuREAL · CC0Saint-Alphonse-de-Granby’s hazards at a glance: a low wildfire record and 8.2% of area homes over the radon guideline
The national fire record shows next to nothing around Saint-Alphonse-de-Granby, 0% of the land within 25 km since 1986 (0.000% a year). Shaking is a bigger worry than in most places, at $0.10 a year per $1,000 of building value ($0.030 typical). Hazard risk gives Saint-Alphonse-de-Granby a grade of C, from earthquakes and radon alone.
What stands out about Saint-Alphonse-de-Granby’s hazards
Four national sources, each read for Saint-Alphonse-de-Granby: earthquakes, radon, past fires and flood studies.
What Saint-Alphonse-de-Granby faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Saint-Alphonse-de-Granby: C
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Saint-Alphonse-de-Granby with little fire nearby would get no credit for it.
Its place: #125 of 507 in Quebec and #2,051 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.
Few fires near Saint-Alphonse-de-Granby: 0% within 5 km, 0% within 25 km
Past fire around Saint-Alphonse-de-Granby’s homes, from the national burned-area record, with the fuel within 5 km.
Forty years of fire maps put Saint-Alphonse-de-Granby at 0.000% a year, low next to the typical Canadian town’s 0.000%.
Nothing inside 5 km of Saint-Alphonse-de-Granby’s homes has burned since 1986, and the nearest scar is 10 km off.
5% of the land within 5 km of Saint-Alphonse-de-Granby is forest fuel, close to the 8% 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
To three decimals the burn rate around Saint-Alphonse-de-Granby is zero, as for 144 of the 513 towns in Quebec, while 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.
Measured against 2,610 towns, Saint-Alphonse-de-Granby is in the largest group, low (92%), and at its floor, while 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.
No flood study is listed for Saint-Alphonse-de-Granby
What Canada’s Flood Map Inventory lists for Saint-Alphonse-de-Granby: who studied flooding and where to see their maps.
Nationally, Saint-Alphonse-de-Granby has no listed flood study; the municipality is the place to ask.
Towns with a flood study on file
Saint-Alphonse-de-Granby has no flood study on file; only 45% of towns in Quebec do, against 58% across Canada.
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 Saint-Alphonse-de-Granby 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.”
Earthquakes cost buildings in Saint-Alphonse-de-Granby $0.10 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
At $0.10 per $1,000, Saint-Alphonse-de-Granby carries roughly 3.3 times the typical Canadian town’s earthquake risk ($0.030).
Shaking damage a year per $1,000 of building value
Earthquake risk in Quebec peaks in La Pocatière ($0.48); Saint-Alphonse-de-Granby, at $0.10, is below 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.
In the upper part of Canada’s range: 26% of its 2,611 towns expect more damage than Saint-Alphonse-de-Granby.
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 Saint-Alphonse-de-Granby’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).
8.2% of homes tested around Saint-Alphonse-de-Granby are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · Area-wide: radon tests, counted over the Monteregie health region
At 8.2% over the guideline, the area around Saint-Alphonse-de-Granby is about level with the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
The typical town in Quebec has 8.2% over 200 Bq/m³; Saint-Alphonse-de-Granby’s area has 8.2%, much the same.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
26% of Canada’s 2,611 towns have more homes over 200 Bq/m³ than Saint-Alphonse-de-Granby’s 5–10% band, which holds 37%.
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.
A survey sample isn’t a map: any home in Saint-Alphonse-de-Granby can be high, and a three-month test is the only way to know.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Saint-Alphonse-de-Granby
Alerts for Saint-Alphonse-de-Granby 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. |
Evacuation orders for Saint-Alphonse-de-Granby come from the municipality or the province, while CWFIS maps fire danger every day.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Saint-Alphonse-de-Granby
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Saint-Alphonse-de-Granby | Low | $0.10 | 8.2% | None listed |
| Brigham 2,386 · 8.3 km | Low | $0.099 | 8.2% | Yes |
| Bromont 12,413 · 9.2 km | Low | $0.067 | 8.2% | Yes |
| Granby 72,180 · 9.3 km | Low | $0.090 | 8.2% | None listed |
| Ange-Gardien 3,100 · 12 km | Low | $0.12 | 8.2% | Yes |
| Cowansville 17,269 · 13 km | Low | $0.089 | 8.2% | None listed |
| Shefford 7,704 · 13 km | Low | $0.052 | 8.2% | Yes |
Saint-Alphonse-de-Granby’s low band tops its neighbours; Brigham is next (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Saint-Alphonse-de-Granby faces
What to do about the hazards Saint-Alphonse-de-Granby 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
- 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 Saint-Alphonse-de-Granby.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Saint-Alphonse-de-Granby takes its 2007 health region’s share.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Saint-Alphonse-de-Granby’s homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- Earthquakes are modelled. Shaking damage is modelled from the ground, the buildings and the odds of each quake, and published for whole subdivisions such as Saint-Alphonse-de-Granby’s.
Questions about flooding and hazards in Saint-Alphonse-de-Granby
How is Saint-Alphonse-de-Granby’s Hazard risk Grade worked out?
Saint-Alphonse-de-Granby grades C for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is radon a problem in Saint-Alphonse-de-Granby?
In Health Canada’s survey, 8.2% of 110 homes tested in Saint-Alphonse-de-Granby’s area were above 200 Bq/m³, though only a test tells you about one house.
Is Saint-Alphonse-de-Granby at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Saint-Alphonse-de-Granby has burned since 1986, the last in 2025, a low band that leaves Risk alone.
Does Saint-Alphonse-de-Granby flood?
Nothing is listed for Saint-Alphonse-de-Granby on the national inventory (0); local maps may still exist with the municipality.
How big is the earthquake risk in Saint-Alphonse-de-Granby?
In NRCan’s seismic model, Saint-Alphonse-de-Granby’s buildings lose $0.10 per $1,000 of value in an average year.
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).