Photo: Harfang · CC BY 3.0Nantes’ hazards at a glance: a low wildfire record and 7.3% of area homes over the radon guideline
Fire has left almost no mark near Nantes: 0% of the land within 25 km since 1986, 0.000% a year. For earthquakes Nantes is middling, $0.040 a year per $1,000 against $0.030 for the typical town. Nantes grades B for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Nantes’s hazards
Four national sources, each read for Nantes: earthquakes, radon, past fires and flood studies.
What Nantes faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Nantes grades B for hazard risk
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Nantes with little fire nearby would get no credit for it.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Only 55 homes were tested in the survey area, so the radon share is rough. Small fires and grass fires are largely missing from the national burned-area record.
Few fires near Nantes: 0% within 5 km, 0% within 25 km
Fires mapped since 1986 around where Nantes’ residents live, and the fuel next to their homes.
With 0.000% burned a year, Nantes is among the many low-band places (the typical Canadian town 0.000%).
Nantes’ homes have had no fire within 5 km since 1986; the closest was 16 km away.
Forest fuel is denser close to Nantes (67% within 5 km) than further out (60% 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
Fire has taken almost none of the land around Nantes, as for 145 of the 514 towns in Quebec; Mistissini tops the list 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.
Nantes 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.
No flood study is listed for Nantes
Flood studies whose area touches Nantes, from NRCan’s inventory, each linked to its owner.
There is no study for Nantes on the national flood inventory, which is far from complete.
Towns with a flood study on file
No study touches Nantes; 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.
Flood mapping is shown for Nantes to be opened and checked, never turned into a grade.
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 Nantes: $0.040 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.
Nantes’ $0.040 is close to the typical town’s $0.030 (1.3 times as much).
Shaking damage a year per $1,000 of building value
The typical town in Quebec expects $0.14 a year in shaking damage; Nantes expects less, $0.040, 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.
Nantes sits mid-range among Canada’s 2,611 towns: 43% expect more shaking damage.
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 Nantes’ 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 about average around Nantes: 7.3% 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
Around Nantes, 7.3% of tested homes topped the guideline, near the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon around Nantes is ordinary for towns in Quebec: 7.3%, beside a median of 8.2%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
A middling share of high tests puts Nantes with 37% of Canada’s 2,611 towns, below 26% of them.
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.
One home in Nantes can be high while next door is low; a three-month test settles it.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Nantes
Alerts for Nantes 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. |
Fire danger and active fires near Nantes are mapped daily by the Canadian Wildland Fire Information System; evacuation orders come from the municipality or province.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Nantes’ neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Nantes | Low | $0.040 | 7.3% | None listed |
| Lac-Mégantic 5,947 · 4.5 km | Low | $0.037 | 7.3% | None listed |
| Frontenac 1,855 · 9.0 km | Low | $0.038 | 7.3% | None listed |
| Lac-Drolet 1,066 · 17 km | Low | $0.046 | 7.3% | None listed |
The neighbour with the most fire is Lac-Mégantic (low), still no more than Nantes (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Nantes faces
What to do about the hazards Nantes 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
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Nantes’ homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- 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 Nantes’.
- 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 Nantes.
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Nantes is its health region’s, the survey’s design unit.
Questions about flooding and hazards in Nantes
Is radon a problem in Nantes?
In Health Canada’s survey, 7.3% of 55 homes tested in Nantes’ area were above 200 Bq/m³, though only a test tells you about one house.
How is Nantes’s Hazard risk Grade worked out?
Nantes grades B for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is Nantes at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Nantes has burned since 1986, the last in 2001, a low band that leaves Risk alone.
How big is the earthquake risk in Nantes?
About $0.040 a year per $1,000 of building value, NRCan’s long-run expectation for Nantes.
Does Nantes flood?
Nothing is listed for Nantes on the national inventory (0); local maps may still exist with the municipality.
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).