Photo: P199 · CC BY-SA 3.0Lac-Supérieur is on Canada’s flood inventory: 2 listed, led by Gouvernement du Québec
Wildfire isn’t Lac-Supérieur’s worry: 0% of the land within 25 km burned since 1986 (0.001% a year). Earthquakes add more: NRCan’s model puts building losses at $0.067 a year per $1,000 of value, against $0.030 for the typical town. Radon is higher than usual: 10% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Lac-Supérieur grades C for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Lac-Supérieur’s hazards
Four national sources, each read for Lac-Supérieur: earthquakes, radon, past fires and flood studies.
What Lac-Supérieur faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Lac-Supérieur grades C for hazard risk
The grade weighs Lac-Supérieur’s seismic risk and radon equally, and wildfire is one-sided: a high band counts against a town, a low one earns nothing.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. The radon share rests on 78 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.
Few fires near Lac-Supérieur: 0% within 5 km, 0% within 25 km
Past fire around Lac-Supérieur’s homes, from the national burned-area record, with the fuel within 5 km.
With 0.001% burned a year, Lac-Supérieur is among the many low-band places (the typical Canadian town 0.000%).
The closest burn since 1986 lies 9.0 km from Lac-Supérieur’s homes, none within 5 km.
41% of the land within 5 km of Lac-Supérieur is forest fuel, close to the 39% 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 514
Lac-Supérieur sits mid-table in Quebec: 136th of 514 towns, at 0.001% a year, well behind Mistissini (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.
The low band takes in 92% of Canada’s 2,610 towns, Lac-Supérieur among them, though its rate is above zero; 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.
Lac-Supérieur is on the flood map inventory: 2 studies, latest by Gouvernement du Québec
What Canada’s Flood Map Inventory lists for Lac-Supérieur: who studied flooding and where to see their maps.
The newest of 2 studies covering Lac-Supérieur is Gouvernement du Québec’s, from 2006; open its map to see the zones.
| Study | By | Year | Status |
|---|---|---|---|
| Lac-Supérieur | Gouvernement du Québec | 2006 | final |
| Lac-Supérieur | Gouvernement du Québec | 2005 | final |
Towns with a flood study on file
Its flood study sets Lac-Supérieur apart in Quebec, where 45% of towns have one (Canada: 58%).
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood studies don’t enter the grade; they are listed so you can open the official map for Lac-Supérieur.
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.
High seismic risk in Lac-Supérieur: $0.067 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
At $0.067 per $1,000, Lac-Supérieur carries roughly 2.2 times the typical Canadian town’s earthquake risk ($0.030).
Shaking damage a year per $1,000 of building value
The typical town in Quebec expects $0.14 a year in shaking damage; Lac-Supérieur expects less, $0.067, 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.
Lac-Supérieur sits above most of Canada’s 2,611 towns on earthquake risk; 29% are higher.
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 loss is to Lac-Supérieur’s buildings alone, from ground shaking; infrastructure and secondary hazards are left out.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Test for radon in Lac-Supérieur: 10% of area homes were over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
Radon runs above the typical Canadian town (6.6%) in Lac-Supérieur’s area, at 10%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
More homes top the guideline around Lac-Supérieur (10%) than in the typical town in Quebec (8.2%); 1.3% went over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Lac-Supérieur is in the 10–20% band, with 22% of Canada’s 2,611 towns; only 4.6% 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.
The share describes the area, not a house: in Lac-Supérieur as anywhere, test to be sure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Not measured by town: radon tests (the Laurentides health region)
Weather and fire alerts for Lac-Supérieur
Alerts for Lac-Supérieur 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 Lac-Supérieur 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)
How Lac-Supérieur’s neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Lac-Supérieur | Low | $0.067 | 10% | Yes |
| Saint-Faustin--Lac-Carré 4,009 · 5.6 km | Low | $0.064 | 10% | None listed |
| Mont-Tremblant 11,879 · 14 km | Low | $0.065 | 10% | Yes |
| Sainte-Agathe-des-Monts 12,154 · 16 km | Low | $0.074 | 10% | Yes |
Among its neighbours Lac-Supérieur has the most fire on record (low); Saint-Faustin--Lac-Carré follows (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Lac-Supérieur faces
What to do about the hazards Lac-Supérieur 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?
- Check the address on the flood map.
- 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-Supérieur is its health region’s, the survey’s design unit.
- 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-Supérieur.
- 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-Supérieur’s.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Lac-Supérieur’s homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
Questions about flooding and hazards in Lac-Supérieur
Is radon a problem in Lac-Supérieur?
In Health Canada’s survey, 10% of 78 homes tested in Lac-Supérieur’s area were above 200 Bq/m³, though only a test tells you about one house.
How big is the earthquake risk in Lac-Supérieur?
In NRCan’s seismic model, Lac-Supérieur’s buildings lose $0.067 per $1,000 of value in an average year.
Is Lac-Supérieur at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Lac-Supérieur has burned since 1986, the last in 2022, a low band that leaves Risk alone.
How is Lac-Supérieur’s Hazard risk Grade worked out?
Lac-Supérieur grades C for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Does Lac-Supérieur flood?
There is flood mapping for Lac-Supérieur on the national inventory, each study linked to its owner’s map, none of them graded.
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).