Photo: Amakuha · CC BY 4.0Hazards in St. John's: wildfire low, radon over the guideline in 12% of tested homes
The burned-area map is nearly blank around St. John's, 0% within 25 km since 1986, 0.001% a year. Earthquakes matter little: NRCan’s model puts building losses at $0.006 a year per $1,000 of value, against $0.030 for the typical town. St. John's grades B+ for hazard risk, with wildfire counted against it.
What stands out about St. John's’s hazards
For St. John's, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What St. John's faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in St. John's: B+
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like St. John's with little fire nearby would get no credit for it.
Its place: #10 of 185 in Manitoba and #940 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Only 66 homes were tested in the survey area, so the radon share is rough. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Little of the land around St. John's has burned: 0% within 5 km, 0% within 25 km since 1986
Past fire around St. John's’ homes, from the national burned-area record, with the fuel within 5 km.
In a typical year 0.001% of the land near St. John's burns; the typical Canadian town sees 0.000%, and both are low.
The closest burn since 1986 lies 18 km from St. John's’ homes, none within 5 km.
Land that isn’t forest covers nearly all the ground around St. John's: forest fuel is 0% within 5 km and 0.1% 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 Manitoba · highest of 189
Flin Flon (Part) burns fastest in Manitoba at 1.68% a year; St. John's, at 0.001%, ranks 31st of 189.
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.
Some fire is mapped around St. John's, but not enough to leave the low band, where 92% of Canada’s 2,610 towns are; 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.
No flood study is listed for St. John's
What Canada’s Flood Map Inventory lists for St. John's: who studied flooding and where to see their maps.
No flood study on the national inventory covers St. John's; ask the municipality, which is the authority for its flood maps.
Towns with a flood study on file
Flood maps are thinner in Manitoba, 18% of towns against 58% nationally, and St. John's has none.
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 St. John's.
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.”
Low seismic risk in St. John's: $0.006 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
St. John's’ $0.006 is a fraction of the typical town’s $0.030 (0.2 times as much): quiet ground by Canadian standards.
Shaking damage a year per $1,000 of building value
St. John's’ $0.006 is close to the median in Manitoba, $0.006; Virden is highest at $0.007.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Earthquakes cost less around St. John's than in 88% of Canada’s 2,611 towns.
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 St. John's 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). · Data for earthquake risk covers the city of Winnipeg
Test for radon in St. John's: 12% of area homes were over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
More homes than usual test high around St. John's: 12% against 6.6% for the typical Canadian town. Behind radon tests sits data gathered across the Winnipeg health region, with St. John's one part of it.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around St. John's, 12% of tests topped the guideline, about the same as the typical town in Manitoba (12%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
St. John's 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.
Radon varies from house to house in St. John's, so the survey is a reason to test, not a result for yours.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in St. John's
Alerts for St. John's 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 St. John's 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)
Hazards in the places around St. John's
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| St. John's | Low | $0.006 | 12% | None listed |
| Luxton 3,047 · 0.7 km | Low | $0.006 | 12% | None listed |
| Inkster-Faraday 3,700 · 1.1 km | Low | $0.006 | 12% | None listed |
| William Whyte 11,432 · 1.4 km | Low | $0.006 | 12% | None listed |
| Seven Oaks 3,244 · 1.6 km | Low | $0.006 | 12% | None listed |
| Jefferson 11,524 · 1.6 km | Low | $0.006 | 12% | None listed |
| North Point Douglas 2,670 · 1.7 km | Low | $0.006 | 12% | None listed |
Among its neighbours St. John's has the most fire on record (low); Luxton follows (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what St. John's faces
What to do about the hazards St. John's 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. 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 St. John'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 St. John's.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, St. John's’ included.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, St. John's takes its 2007 health region’s share.
Questions about flooding and hazards in St. John's
How is St. John's’s Hazard risk Grade worked out?
St. John's’ Hazard risk grade is B+, built on earthquakes and radon with a one-sided wildfire input.
Is St. John's at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of St. John's has burned since 1986, the last in 2012, a low band that leaves Risk alone.
Is radon a problem in St. John's?
In Health Canada’s survey, 12% of 66 homes tested in St. John's’ area were above 200 Bq/m³, though only a test tells you about one house.
How big is the earthquake risk in St. John's?
NRCan’s model expects shaking to cost buildings in St. John's $0.006 a year for every $1,000 of their value, on average over many years.
Does St. John's flood?
Nothing is listed for St. John's 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).