Photo: Simon Villeneuve · CC BY-SA 3.0Lac-Mégantic’s hazards at a glance: a low wildfire record and 7.3% of area homes over the radon guideline
For Lac-Mégantic, wildfire history is close to nil: 0% of nearby land since 1986, 0.000% a year. Shaking is about as much of a worry in Lac-Mégantic as in most places, at $0.037 a year per $1,000 of building value ($0.030 typical). Hazard risk gives Lac-Mégantic a grade of B+, from earthquakes and radon alone.
What stands out about Lac-Mégantic’s hazards
Four national sources, each read for Lac-Mégantic: earthquakes, radon, past fires and flood studies.
What Lac-Mégantic faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Lac-Mégantic: B+
For Lac-Mégantic, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #48 of 507 in Quebec and #1,395 of 2,589 Canadian towns.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. The radon share rests on 55 home tests in the survey area, so a few homes move it. Small fires and grass fires are largely missing from the national burned-area record.
Little of the land around Lac-Mégantic has burned: 0% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where Lac-Mégantic’s residents live, and the fuel next to their homes.
Low: the land around Lac-Mégantic burns at 0.000% a year, where the typical Canadian town sees 0.000%.
Nothing inside 5 km of Lac-Mégantic’s homes has burned since 1986, and the nearest scar is 25 km off.
63% of the land within 5 km of Lac-Mégantic is forest fuel, close to the 59% 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
Little or nothing burns around Lac-Mégantic in a typical year; 144 of the 513 towns in Quebec share that, and Mistissini leads 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.
Lac-Mégantic shares the low band with 92% of Canada’s 2,610 towns, its burn rate rounding to nothing; 7.5% burn faster.
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.
The flood map inventory lists nothing for Lac-Mégantic
Flood studies whose area touches Lac-Mégantic, from NRCan’s inventory, each linked to its owner.
The inventory has nothing for Lac-Mégantic, but a local or conservation-authority map may still exist.
Towns with a flood study on file
Lac-Mégantic 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.
The grade leaves flood out, since a study area says nothing about how many of Lac-Mégantic’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-Mégantic: $0.037 per $1,000 of buildings a year
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
Lac-Mégantic’s $0.037 is close to the typical town’s $0.030 (1.2 times as much).
Shaking damage a year per $1,000 of building value
Below the middle in Quebec: Lac-Mégantic’s $0.037 against a median of $0.14; La Pocatière has $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.
Around half of Canada’s 2,611 towns expect more shaking damage than Lac-Mégantic (45%).
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).
Roads, pipes and bridges aren’t in Lac-Mégantic’s figure, nor landslides or tsunami: it is buildings and shaking.
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 Lac-Mégantic: 7.3% of area homes over the 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 Estrie health region
Lac-Mégantic’s area, at 7.3%, 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; Lac-Mégantic’s area has 7.3%, much the same.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Between 5% and 10% of tests over the guideline: Lac-Mégantic, and 37% of Canada’s 2,611 towns; 26% are 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.
Basements, soil and how a house is sealed decide its radon, so in Lac-Mégantic only a test can say.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Lac-Mégantic
Environment and Climate Change Canada issues the weather alerts for Lac-Mégantic; 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. |
In fire season, check CWFIS for danger and active fires around Lac-Mégantic, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Lac-Mégantic’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Lac-Mégantic | Low | $0.037 | 7.3% | None listed |
| Nantes 1,412 · 4.5 km | Low | $0.040 | 7.3% | None listed |
| Frontenac 1,855 · 4.7 km | Low | $0.038 | 7.3% | None listed |
| Lac-Drolet 1,066 · 18 km | Low | $0.046 | 7.3% | None listed |
The neighbour with the most fire is Nantes (low), still no more than Lac-Mégantic (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Lac-Mégantic faces
Practical steps for Lac-Mégantic’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?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
What this data can and can’t tell you
- 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 Lac-Mégantic’s.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Lac-Mégantic’s homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- Radon is a survey. The radon share comes from about 14,000 long-term home tests in 2009–2011, pooled for now by the 2007 health region Lac-Mégantic sits in.
- Flood studies aren’t flood zones. A study’s area can be a whole watershed or province, so being on the inventory says a map exists, not that a home in Lac-Mégantic floods.
Questions about flooding and hazards in Lac-Mégantic
Is Lac-Mégantic at risk of wildfire?
Some, but Lac-Mégantic’s low band (0% of nearby land burned since 1986, latest 2001) is short of the level that counts.
How is Lac-Mégantic’s Hazard risk Grade worked out?
Hazard risk gives Lac-Mégantic B+, weighing earthquakes and radon and counting wildfire only against it.
Is radon a problem in Lac-Mégantic?
The area’s survey found 7.3% of 55 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Lac-Mégantic.
Does Lac-Mégantic flood?
The inventory has 0 studies for Lac-Mégantic, and an empty list isn’t a clean bill: the municipality holds any flood maps.
How big is the earthquake risk in Lac-Mégantic?
About $0.037 a year per $1,000 of building value, NRCan’s long-run expectation for Lac-Mégantic.
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).