Photo: MTLskyline · CC BY-SA 3.0Lac-Brome’s hazards at a glance: a low wildfire record and 8.2% of area homes over the radon guideline
Wildfire barely registers for Lac-Brome, at 0% of the land within 25 km since 1986 (0.000% a year). For earthquakes Lac-Brome is middling, $0.051 a year per $1,000 against $0.030 for the typical town. Lac-Brome grades C+ for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Lac-Brome’s hazards
For Lac-Brome, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Lac-Brome faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Lac-Brome grades C+ for hazard risk
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Lac-Brome with little fire nearby would get no credit for it.
Its place: #108 of 507 in Quebec and #1,799 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.
Little of the land around Lac-Brome has burned: 0% within 5 km, 0% within 25 km since 1986
Past fire around Lac-Brome’s homes, from the national burned-area record, with the fuel within 5 km.
In a typical year 0.000% of the land near Lac-Brome burns; the typical Canadian town sees 0.000%, and both are low.
Since 1986 the nearest fire to Lac-Brome’s homes came within 15 km, never inside 5 km.
About as much forest grows next to Lac-Brome’s homes (21% within 5 km) as across 25 km (17%).
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); Lac-Brome 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.
92% of Canada’s 2,610 towns are in the low band and 7.5% above it; Lac-Brome is among the many where the yearly burn rate 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 Lac-Brome
What Canada’s Flood Map Inventory lists for Lac-Brome: who studied flooding and where to see their maps.
The inventory has nothing for Lac-Brome, but a local or conservation-authority map may still exist.
Towns with a flood study on file
No study touches Lac-Brome; 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.
The grade leaves flood out, since a study area says nothing about how many of Lac-Brome’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.”
Ordinary seismic risk in Lac-Brome: $0.051 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Nothing unusual about Lac-Brome’s ground: $0.051 against a typical $0.030, 1.7 times.
Shaking damage a year per $1,000 of building value
The typical town in Quebec expects $0.14 a year in shaking damage; Lac-Brome expects less, $0.051, and La Pocatière the most, $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 30% of Canada’s 2,611 towns are above Lac-Brome.
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).
For Lac-Brome the model prices shaking damage to buildings, nothing more.
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 Lac-Brome: 8.2% over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
The survey area of Lac-Brome reads 8.2%, a shade from the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Lac-Brome, 8.2% of tests topped the guideline, about the same as the typical town in Quebec (8.2%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Lac-Brome is in the 5–10% band with 37% of Canada’s 2,611 towns; 26% have more.
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.
Neighbouring homes in Lac-Brome can differ a lot; only a long-term test tells you about yours.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Radon tests: the Monteregie health region
Where to get warnings in Lac-Brome
Environment and Climate Change Canada issues the weather alerts for Lac-Brome; 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 Lac-Brome, 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 Lac-Brome
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Lac-Brome | Low | $0.051 | 8.2% | None listed |
| Waterloo 5,714 · 12 km | Low | $0.051 | 8.2% | Yes |
| Bromont 12,413 · 13 km | Low | $0.067 | 8.2% | Yes |
| Bolton-Est 1,337 · 16 km | Low | $0.036 | 7.3% | None listed |
| Shefford 7,704 · 16 km | Low | $0.052 | 8.2% | Yes |
| Sutton 4,775 · 16 km | Low | $0.045 | 8.2% | None listed |
| Stukely-Sud 1,242 · 17 km | Low | $0.053 | 7.3% | None listed |
Nowhere around Lac-Brome burns more: Waterloo, 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 Lac-Brome faces
What to do about the hazards Lac-Brome 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
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Lac-Brome is its health region’s, the survey’s design unit.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Lac-Brome’s census subdivision (a neighbourhood shows its city’s).
- Wildfire counts one way. For Lac-Brome, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- 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 Lac-Brome.
Questions about flooding and hazards in Lac-Brome
How big is the earthquake risk in Lac-Brome?
In NRCan’s seismic model, Lac-Brome’s buildings lose $0.051 per $1,000 of value in an average year.
Is Lac-Brome at risk of wildfire?
Fire has reached 0% of the land around Lac-Brome since 1986 (last in 2016); at low, it neither helps nor hurts the grade.
How is Lac-Brome’s Hazard risk Grade worked out?
Lac-Brome grades C+ for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Does Lac-Brome flood?
With 0 studies on the inventory, Lac-Brome’s flood risk is unmapped nationally; check with the municipality before buying.
Is radon a problem in Lac-Brome?
Around Lac-Brome, 110 survey homes were tested and 8.2% 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).