Photo: Roncanada · CC BY 4.0Hazard risk in Thurso is higher than in 88% of Canadian towns
Wildfire isn’t Thurso’s worry: 0% of the land within 25 km burned since 1986 (0.001% a year). Seismic risk runs high: $0.12 of expected damage per $1,000 of buildings a year, the typical town $0.030. In Health Canada’s survey, 13% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Thurso grades D for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Thurso’s hazards
For Thurso, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Thurso faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Thurso: D
Seismic risk and radon set Thurso’s grade, wildfire can drag it down, and flood mapping stays out of it.
Its place: #442 of 507 in Quebec and #2,435 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. The radon share rests on 63 home tests in the survey area, so a few homes move it. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Few fires near Thurso: 0% within 5 km, 0% within 25 km
Past fire around Thurso’s homes, from the national burned-area record, with the fuel within 5 km.
A burn rate of 0.001% a year keeps Thurso in the low band (the typical Canadian town: 0.000%).
The closest burn since 1986 lies 13 km from Thurso’s homes, none within 5 km.
14% of the land within 5 km of Thurso is forest fuel, close to the 14% 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
Thurso burns at 0.001% a year, 136th of 513 towns in Quebec; the leader, Mistissini, reaches 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.
Thurso is in the low band with 92% of Canada’s 2,610 towns; 7.5% sit in moderate or 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.
No flood study is listed for Thurso
What Canada’s Flood Map Inventory lists for Thurso: who studied flooding and where to see their maps.
Canada’s Flood Map Inventory lists no study whose area touches Thurso, which doesn’t mean it has never been mapped.
Towns with a flood study on file
Flood maps are thinner in Quebec, 45% of towns against 58% nationally, and Thurso has none.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Listed, not scored: a flood study proves a map exists, not that Thurso floods.
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.”
Earthquakes cost buildings in Thurso $0.12 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Thurso’s $0.12 is about 3.8 times the typical town’s $0.030: it sits in one of Canada’s more active seismic zones.
Shaking damage a year per $1,000 of building value
Neither high nor low in Quebec: Thurso’s $0.12 sits by the median of $0.14, while La Pocatière reaches $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.
In the upper part of Canada’s range: 24% of its 2,611 towns expect more damage than Thurso.
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).
Only shaking damage to buildings in Thurso is counted; landslides, liquefaction, tsunami and fire after a quake aren’t.
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 Thurso: 13% of tested homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
A higher share than most: 13% of tested homes around Thurso, the typical Canadian town 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Thurso than in most towns in Quebec: 13% over the guideline (8.2% is typical), 4.8% over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
The 10–20% band holds 22% of Canada’s 2,611 towns, Thurso among them; 4.6% rank above.
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.
Health Canada advises testing every home, Thurso’s included, whatever the area’s figure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Radon tests published for the Outaouais health region, not by town
Where to get warnings in Thurso
Alerts for Thurso 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 Thurso 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 Thurso’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 |
|---|---|---|---|---|
| Thurso | Low | $0.12 | 13% | None listed |
| Lochaber-Partie-Ouest 1,016 · 6.8 km | Low | $0.10 | 13% | Yes |
| Rockland 30,375 · 7.7 km | Low | $0.16 | 6.1% | Yes |
| Plaisance 1,191 · 10 km | Low | $0.11 | 13% | None listed |
| L'Ange-Gardien 7,068 · 13 km | Low | $0.095 | 13% | Yes |
| Vallée-de-la-Lièvre 15,388 · 14 km | Low | $0.12 | 13% | Yes |
| Cumberland 6,139 · 17 km | Low | $0.15 | 6.2% | Yes |
None of the places around has more fire nearby than Thurso (low); Lochaber-Partie-Ouest comes closest (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Thurso faces
Practical steps for Thurso’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.
- Drop, cover and hold on.
- Strap the water heater down.
- Keep 72 hours of supplies.
- Has it had a radon test?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
- Is earthquake cover included?
What this data can and can’t tell you
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Thurso’s included.
- Flood studies aren’t flood zones. The flood inventory points to maps; it is incomplete and not the official source, so ask the municipality about any street in Thurso.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Thurso takes its 2007 health region’s share.
- Wildfire counts one way. Burned land within 25 km of where people live, averaged over 1986–2025 and checked for fuel near homes, is the measure; it looks back, not ahead, and only ever counts against Thurso.
Questions about flooding and hazards in Thurso
How is Thurso’s Hazard risk Grade worked out?
Thurso’s Hazard risk grade is D, built on earthquakes and radon with a one-sided wildfire input.
How big is the earthquake risk in Thurso?
NRCan’s model expects shaking to cost buildings in Thurso $0.12 a year for every $1,000 of their value, on average over many years.
Is Thurso at risk of wildfire?
Not much by Canadian standards: Thurso’s band is low, with 0% of the land within 25 km burned since 1986 (last in 2025), so wildfire doesn’t change its grade.
Does Thurso flood?
No study on Canada’s Flood Map Inventory covers Thurso (0), which doesn’t mean it has never been mapped, so ask the municipality.
Is radon a problem in Thurso?
13% of the 63 homes Health Canada tested around Thurso topped the guideline; your own house needs its own test.
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).