Photo: Gabriel Picard · CC BY-SA 4.0A flood study covers Bromont: 3 on the national inventory, the newest from Gouvernement du Québec
The national fire record shows next to nothing around Bromont, 0% of the land within 25 km since 1986 (0.000% a year). Shaking is a bigger worry than in most places, at $0.067 a year per $1,000 of building value ($0.030 typical). About as many homes carry radon around Bromont as elsewhere, 8.2% over the guideline where the typical town has 6.6%. Bromont grades C+ for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Bromont’s hazards
For Bromont, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Bromont faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Bromont: C+
Earthquake risk and radon make Bromont’s grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
Its place: #116 of 507 in Quebec and #1,856 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 Bromont: 0% within 5 km, 0% within 25 km
Fires mapped since 1986 around where Bromont’s residents live, and the fuel next to their homes.
Next to the typical Canadian town (0.000% a year), Bromont’s 0.000% is in the low band.
Bromont’s homes have had no fire within 5 km since 1986; the closest was 15 km away.
13% of the land within 5 km of Bromont is forest fuel, close to the 12% 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
Among the 513 towns in Quebec, Mistissini burns fastest (0.31% a year); Bromont is with the 144 near zero.
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.
The low band holds 92% of Canada’s 2,610 towns, and Bromont sits at its very bottom; only 7.5% are above it.
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.
Flooding around Bromont is mapped in 3 studies, the newest by Gouvernement du Québec
Flood studies whose area touches Bromont, from NRCan’s inventory, each linked to its owner.
For Bromont the inventory points to 3 studies, most recently Gouvernement du Québec’s in 2006.
| Study | By | Year | Status |
|---|---|---|---|
| Bromont | Gouvernement du Québec | 2006 | final |
| Brigham-Adamsville | Gouvernement du Québec | 2005 | final |
| Bromont-Adamsville | Gouvernement du Québec | 2005 | final |
Towns with a flood study on file
Bromont is one of the 45% of towns in Quebec with a flood study on file, fewer than Canada’s 58%.
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 Bromont’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.”
Natural Resources Canada, Canada Flood Map Inventory; links go to each study’s owner.
Shaking is Bromont’s costliest hazard: $0.067 a year per $1,000
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
Roughly 2.2 times the typical $0.030: Bromont’s $0.067 marks real seismic exposure.
Shaking damage a year per $1,000 of building value
At $0.067, Bromont is below the typical town in Quebec ($0.14); La Pocatière is 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.
In the upper part of Canada’s range: 29% of its 2,611 towns expect more damage than Bromont.
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 Bromont.
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 Bromont are over the radon guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Area-wide: radon tests, counted over the Monteregie health region
Bromont’s area, at 8.2%, is close to the 6.6% of the typical Canadian town.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
The typical town in Quebec has 8.2% over 200 Bq/m³; Bromont’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.
37% of Canada’s 2,611 towns share Bromont’s band of 5 to 10%; 26% sit 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.
A low area share in Bromont doesn’t clear a house, nor does a high one condemn it: test.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Bromont
Environment and Climate Change Canada issues the weather alerts for Bromont; 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. |
For fires near Bromont, the national fire information system maps danger and active fires daily; local authorities give any evacuation order.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Bromont
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Bromont | Low | $0.067 | 8.2% | Yes |
| Shefford 7,704 · 7.3 km | Low | $0.052 | 8.2% | Yes |
| Saint-Alphonse-de-Granby 3,545 · 9.2 km | Low | $0.10 | 8.2% | None listed |
| Granby 72,180 · 12 km | Low | $0.090 | 8.2% | None listed |
| Brigham 2,386 · 12 km | Low | $0.099 | 8.2% | Yes |
| Waterloo 5,714 · 12 km | Low | $0.051 | 8.2% | Yes |
| Cowansville 17,269 · 13 km | Low | $0.089 | 8.2% | None listed |
None of the places around has more fire nearby than Bromont (low); Shefford comes closest (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Bromont faces
Practical steps for Bromont’s hazards, most pressing first.
- 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?
- Check the address on the flood map.
- Are flood and wildfire insured?
What this data can and can’t tell you
- 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 Bromont.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Bromont’s included.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Bromont 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 Bromont.
Questions about flooding and hazards in Bromont
How is Bromont’s Hazard risk Grade worked out?
Bromont grades C+ for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
How big is the earthquake risk in Bromont?
Expected earthquake damage in Bromont comes to $0.067 a year for each $1,000 that buildings are worth.
Is Bromont at risk of wildfire?
Some, but Bromont’s low band (0% of nearby land burned since 1986, latest 2025) is short of the level that counts.
Is radon a problem in Bromont?
The area’s survey found 8.2% of 110 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Bromont.
Does Bromont flood?
The inventory lists a study touching Bromont; whether a given street floods is on that map, not in 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).