Photo: Robert Garry · CC BY-SA 4.0Wildfire low, radon 13%: how Thetford Mines stands on hazards
For Thetford Mines, wildfire history is close to nil: 0% of nearby land since 1986, 0.000% a year. NRCan expects $0.049 of shaking damage a year per $1,000 of buildings in Thetford Mines, near the typical $0.030. Hazard risk gives Thetford Mines a grade of C−, from earthquakes and radon alone.
What stands out about Thetford Mines’s hazards
Four national sources, each read for Thetford Mines: earthquakes, radon, past fires and flood studies.
What Thetford Mines faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Thetford Mines: C−
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Thetford Mines with little fire nearby would get no credit for it.
Its place: #341 of 507 in Quebec and #2,307 of 2,589 Canadian towns.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. Small fires and grass fires are largely missing from the national burned-area record.
Wildfire is rare near Thetford Mines: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Thetford Mines’ residents live, and the fuel next to their homes.
Next to the typical Canadian town (0.000% a year), Thetford Mines’ 0.000% is in the low band.
Thetford Mines’ homes have had no fire within 5 km since 1986; the closest was 24 km away.
Forest fuel is spread evenly around Thetford Mines: 52% within 5 km, 49% 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); Thetford Mines 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 Thetford Mines 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.
The flood map inventory lists nothing for Thetford Mines
Flood studies whose area touches Thetford Mines, from NRCan’s inventory, each linked to its owner.
An empty entry for Thetford Mines on the inventory isn’t proof of safety; ask locally for flood maps.
Towns with a flood study on file
Thetford Mines 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.
Nothing here counts toward Risk; the studies are pointers to the maps their owners keep for Thetford Mines.
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 Thetford Mines: $0.049 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.
At $0.049 per $1,000, Thetford Mines’ earthquake risk is about the typical Canadian town’s ($0.030; 1.6 times).
Shaking damage a year per $1,000 of building value
At $0.049, Thetford Mines 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.
More earthquake risk than most: only 31% of Canada’s 2,611 towns are above Thetford Mines.
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 Thetford Mines’ 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).
Radon runs high around Thetford Mines: 13% of tested homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
Thetford Mines’ survey area reads 13% over the guideline, well past the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Thetford Mines, 13% of tests were over 200 Bq/m³ and 0.6% over 600, against a median of 8.2% in Quebec.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
4.6% of Canada’s 2,611 towns have a higher share of homes over 200 Bq/m³ than Thetford Mines, in the 10–20% band with 22%.
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 survey sample isn’t a map: any home in Thetford Mines can be high, and a three-month test is the only way to know.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Area behind the radon tests figures: the Chaudiere-Appalaches health region
Weather and fire alerts for Thetford Mines
Environment and Climate Change Canada issues the weather alerts for Thetford Mines; 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. |
Smoke and fire warnings for Thetford Mines come through Environment Canada and Alert Ready; the fire map is CWFIS’s.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Thetford Mines
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Thetford Mines | Low | $0.049 | 13% | None listed |
| Saint-Joseph-de-Coleraine 1,920 · 15 km | Low | $0.045 | 13% | None listed |
| Adstock 3,203 · 17 km | Low | $0.045 | 13% | None listed |
Fire is no heavier anywhere nearby than around Thetford Mines (low), with Saint-Joseph-de-Coleraine next at low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Thetford Mines faces
What to do about the hazards Thetford Mines 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. Radon figures pool the survey’s home tests by area: postal areas once their boundaries arrive, the 2007 health region around Thetford Mines until then.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Thetford Mines’ homes since 1986, a history of fire that may lower Risk but never raises it.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Thetford Mines’ figure is its subdivision’s.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Thetford Mines without grading them.
Questions about flooding and hazards in Thetford Mines
Is Thetford Mines at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Thetford Mines has burned since 1986, the last in 2016, a low band that leaves Risk alone.
How is Thetford Mines’s Hazard risk Grade worked out?
Thetford Mines’ Hazard risk grade is C−, built on earthquakes and radon with a one-sided wildfire input.
Is radon a problem in Thetford Mines?
In Health Canada’s survey, 13% of 175 homes tested in Thetford Mines’ area were above 200 Bq/m³, though only a test tells you about one house.
Does Thetford Mines flood?
Nothing is listed for Thetford Mines on the national inventory (0); local maps may still exist with the municipality.
How big is the earthquake risk in Thetford Mines?
Expected earthquake damage in Thetford Mines comes to $0.049 a year for each $1,000 that buildings are worth.
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).