Photo: JohnHinks · CC BY-SA 3.0Stephenville is on Canada’s flood inventory: 1 listed, led by Department of Environment and Climate Change
Little of the land around Stephenville has burned: 0.2% within 25 km since 1986, or 0.005% a year. Shaking is less of a worry than in most places, at $0.011 a year per $1,000 of building value ($0.030 typical). Radon is higher than usual: 10% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Hazard risk gives Stephenville a grade of B+; its wildfire band pulls it down.
What stands out about Stephenville’s hazards
For Stephenville, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Stephenville faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Stephenville grades B+ for hazard risk
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Stephenville with little fire nearby would get no credit for it.
Its place: #28 of 32 in Newfoundland and Labrador and #1,094 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Wildfire is rare near Stephenville: 0.2% of the land within 25 km burned since 1986, 1.6% within 5 km
Fires mapped since 1986 around where Stephenville’s residents live, and the fuel next to their homes.
With 0.005% burned a year, Stephenville is among the many low-band places (the typical Canadian town 0.000%).
66% of the land within 5 km of Stephenville is forest fuel, close to the 69% 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 Newfoundland and Labrador · highest of 32
Some fire is mapped around Stephenville (0.005% a year), but it ranks only 23rd of 32 towns in Newfoundland and Labrador; Labrador City has 0.43%.
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.
Stephenville 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.
A flood study covers Stephenville, from Department of Environment and Climate Change: 1 on the inventory
Flood studies whose area touches Stephenville, from NRCan’s inventory, each linked to its owner.
Department of Environment and Climate Change holds the flood mapping that covers Stephenville (2009), linked below.
| Study | By | Year | Status |
|---|---|---|---|
| Stephenville | Department of Environment and Climate Change | 2009 | final |
Towns with a flood study on file
Stephenville is one of the 59% of towns in Newfoundland and Labrador with a flood study on file; across Canada it is 58%.
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 Stephenville 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.”
Natural Resources Canada, Canada Flood Map Inventory; links go to each study’s owner.
Earthquakes cost buildings in Stephenville just $0.011 per $1,000 a year
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
Stephenville’s $0.011 is a fraction of the typical town’s $0.030 (0.4 times as much): quiet ground by Canadian standards.
Shaking damage a year per $1,000 of building value
Earthquake risk around Stephenville ($0.011) matches the middle in Newfoundland and Labrador ($0.011), far from Holyrood’s $0.015.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Most of Canada’s 2,611 towns (85%) face more earthquake damage than Stephenville.
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).
For Stephenville the model prices shaking damage to buildings, nothing more.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
10% of homes tested around Stephenville are over the radon guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
At 10% over the guideline, the area around Stephenville beats the typical Canadian town’s 6.6%. Nobody publishes radon tests for Stephenville alone, so this card uses the figure for the Western Regional Integrated Health Authority.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Stephenville than in most towns in Newfoundland and Labrador: 10% over the guideline (4% is typical), 1.9% over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
More high tests than most: Stephenville sits in a band that only 22% of Canada’s 2,611 towns share, with 4.6% 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.
Neighbouring homes in Stephenville can differ a lot; only a long-term test tells you about yours.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Stephenville
Alerts for Stephenville 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 Stephenville 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 Stephenville’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Stephenville | Low | $0.011 | 10% | Yes |
| Kippens 1,927 · 2.9 km | Low | $0.007 | 10% | Yes |
| Stephenville Crossing 1,731 · 12 km | Low | $0.013 | 10% | Yes |
| St. George's 1,181 · 15 km | Low | $0.010 | 10% | None listed |
St. George's burns a little more than Stephenville, in the same low band (low here).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Stephenville faces
What to do about the hazards Stephenville 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
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Stephenville’s census subdivision (a neighbourhood shows its city’s).
- 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 Stephenville.
- Wildfire counts one way. For Stephenville, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Stephenville takes its 2007 health region’s share.
Questions about flooding and hazards in Stephenville
How is Stephenville’s Hazard risk Grade worked out?
Stephenville grades B+ for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
How big is the earthquake risk in Stephenville?
About $0.011 a year per $1,000 of building value, NRCan’s long-run expectation for Stephenville.
Is Stephenville at risk of wildfire?
Less than most of Canada: 0.2% of the land within 25 km of Stephenville has burned since 1986, the last in 1986, a low band that leaves Risk alone.
Is radon a problem in Stephenville?
In Health Canada’s survey, 10% of 211 homes tested in Stephenville’s area were above 200 Bq/m³, though only a test tells you about one house.
Does Stephenville flood?
The inventory lists a study touching Stephenville; whether a given street floods is on that map, not in the grade.
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).