Photo: art_inthecity from Montréal, CA · CC BY 2.0Wildfire low, radon 8.2%: how Granby stands on hazards
Burn scars are few around Granby, with 0% of the land within 25 km touched by fire since 1986 (0.000% a year). Shaking is a bigger worry than in most places, at $0.090 a year per $1,000 of building value ($0.030 typical). Granby grades C+ for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Granby’s hazards
For Granby, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Granby faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Granby grades C+ for hazard risk
Two inputs always count for Granby, earthquakes and radon; the third, wildfire, counts only against a town.
Its place: #122 of 507 in Quebec and #2,037 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 Granby: 0% within 5 km, 0% within 25 km
Past fire around Granby’s homes, from the national burned-area record, with the fuel within 5 km.
Forty years of fire maps put Granby at 0.000% a year, low next to the typical Canadian town’s 0.000%.
Near or far, forest fuel covers a similar share around Granby: 5.4% within 5 km and 8.4% 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
Near-zero burning puts Granby with 144 of the 513 towns in Quebec, far below Mistissini 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.
Most of the country’s 2,610 towns are low-band (92%, against 7.5% above); around Granby, burning rounds to zero.
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 Granby
What Canada’s Flood Map Inventory lists for Granby: who studied flooding and where to see their maps.
Nationally, Granby has no listed flood study; the municipality is the place to ask.
Towns with a flood study on file
No study touches Granby; 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 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 Granby $0.090 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; Granby loses $0.090, 3 times as much.
Shaking damage a year per $1,000 of building value
Granby’s $0.090 sits under the median in Quebec, $0.14, and well under La Pocatière’s $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: 27% of its 2,611 towns expect more damage than 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).
What a quake does after the shaking, fire, landslides, tsunami, falls outside NRCan’s figure for Granby.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Radon about average around Granby: 8.2% over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
The survey area of Granby reads 8.2%, a shade from the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon around Granby is ordinary for towns in Quebec: 8.2%, beside a median of 8.2%.
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 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.
Whatever Granby’s area share, the reading that matters is your own home’s, over a winter.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Data for radon tests covers the Monteregie health region
Where to get warnings in Granby
Alerts for 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 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 Granby
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Granby | Low | $0.090 | 8.2% | None listed |
| Sainte-Cécile-de-Milton 2,267 · 9.1 km | Low | $0.098 | 8.2% | None listed |
| Saint-Alphonse-de-Granby 3,545 · 9.3 km | Low | $0.10 | 8.2% | None listed |
| Roxton Pond 4,884 · 9.6 km | Low | $0.071 | 8.2% | None listed |
| Shefford 7,704 · 9.7 km | Low | $0.052 | 8.2% | Yes |
| Bromont 12,413 · 12 km | Low | $0.067 | 8.2% | Yes |
| Saint-Paul-d'Abbotsford 2,891 · 12 km | Low | $0.096 | 8.2% | Yes |
The fire record around Saint-Paul-d'Abbotsford is a touch heavier than Granby’s, but the band is the same: low (here low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Granby faces
What to do about the hazards 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.
- Clear needles and wood nearby.
- Keep a grab-and-go bag ready.
- In smoke, stay in; filter air.
- Has it had a radon test?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
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 Granby.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Granby’s census subdivision (a neighbourhood shows its city’s).
- Wildfire counts one way. For Granby, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Granby is its health region’s, the survey’s design unit.
Questions about flooding and hazards in Granby
How is Granby’s Hazard risk Grade worked out?
Granby’s Hazard risk grade is C+, built on earthquakes and radon with a one-sided wildfire input.
Is radon a problem in Granby?
Around Granby, 110 survey homes were tested and 8.2% came in over 200 Bq/m³, a guide to the area, not to any one home.
Does Granby flood?
With 0 studies on the inventory, Granby’s flood risk is unmapped nationally; check with the municipality before buying.
How big is the earthquake risk in Granby?
NRCan’s model expects shaking to cost buildings in Granby $0.090 a year for every $1,000 of their value, on average over many years.
Is Granby at risk of wildfire?
Fire has reached 0% of the land around Granby since 1986 (last in 2025); at low, it neither helps nor hurts the grade.
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).