Photo: Verne Equinox · CC BY-SA 3.0Hazard risk in St. Mary's is lower than in 91% of Canadian towns
The burned-area map is nearly blank around St. Mary's, 0% within 25 km since 1986, 0.001% a year. NRCan expects $0.017 of shaking damage a year per $1,000 of buildings in St. Mary's, near the typical $0.030. In Health Canada’s survey, just 2% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Hazard risk gives St. Mary's a grade of A; its wildfire band pulls it down.
What stands out about St. Mary's’s hazards
Four national sources, each read for St. Mary's: earthquakes, radon, past fires and flood studies.
What St. Mary's faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
St. Mary's grades A for hazard risk
The grade weighs St. Mary's’ seismic risk and radon equally, and wildfire is one-sided: a high band counts against a town, a low one earns nothing.
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 St. Mary's: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where St. Mary's’ residents live, and the fuel next to their homes.
The yearly burn rate around St. Mary's is 0.001%, low beside 0.000% for the typical Canadian town.
The closest burn since 1986 lies 6.5 km from St. Mary's’ homes, none within 5 km.
The ring nearest St. Mary's is the most wooded: 91% forest fuel within 5 km against 85% 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 Nova Scotia · highest of 91
In the lower half in Nova Scotia: St. Mary's at 0.001% a year, 69th of 91, far from Barrington’s 0.46%.
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 takes in 92% of Canada’s 2,610 towns, St. Mary's among them, though its rate is above zero; 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.
3 flood studies cover St. Mary's, the newest from Halifax Regional Municipality
Flood studies whose area touches St. Mary's, from NRCan’s inventory, each linked to its owner.
For St. Mary's the inventory points to 3 studies, most recently Halifax Regional Municipality’s in 2024.
| Study | By | Year | Status |
|---|---|---|---|
| Creation of Coastal, Pluvial, Fluvial Flood Hazard Maps for Halifax Regional Municipality | Halifax Regional Municipality | 2024 | final |
| Eastern Shore Flood Mapping Area | Province of Nova Scotia | 2024 | final · not public |
| South/West Primary Watershed | Province of Nova Scotia | 2023 | final · not public |
Towns with a flood study on file
Flood maps are common in Nova Scotia: 88% of towns have one, against 58% nationally, and St. Mary's is among them.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
The grade leaves flood out, since a study area says nothing about how many of St. Mary's’ homes are at risk.
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 St. Mary's $0.017 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.
With $0.017 of shaking damage a year per $1,000, St. Mary's is about even with the typical $0.030 (0.6 times).
Shaking damage a year per $1,000 of building value
About level with the typical town in Nova Scotia: St. Mary's’ $0.017 against $0.018; Clare reaches $0.034.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
St. Mary's is in the lower part of Canada’s range for earthquake risk; 70% of the 2,611 towns are higher.
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).
Roads, pipes and bridges aren’t in St. Mary's’ figure, nor landslides or tsunami: it is buildings and shaking.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Radon runs low around St. Mary's: 2% of tested homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
Where the typical Canadian town has 6.6% of homes over the guideline, St. Mary's’ area has fewer, 2%. St. Mary's doesn’t get its own radon tests figures; the ones here come from the Zone 4 health region.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
The median in Nova Scotia is 13% over 200 Bq/m³; around St. Mary's it is 2%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
The quietest radon band, under 5%, holds 37% of Canada’s 2,611 towns and St. Mary's; 63% sit 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.
A survey sample isn’t a map: any home in St. Mary's 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).
Weather and fire alerts for St. Mary's
Environment and Climate Change Canada issues the weather alerts for St. Mary's; 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. |
In fire season, check CWFIS for danger and active fires around St. Mary's, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Get ready for what St. Mary's faces
What to do about the hazards St. Mary'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?
- Check the address on the flood map.
- Are flood and wildfire insured?
What this data can and can’t tell you
- 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 St. Mary's’.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of St. Mary's’ homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for St. Mary's without grading them.
- 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 St. Mary's until then.
Questions about flooding and hazards in St. Mary's
How is St. Mary's’s Hazard risk Grade worked out?
St. Mary's grades A for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Does St. Mary's flood?
A flood study covers St. Mary's on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
Is St. Mary's at risk of wildfire?
Fire has reached 0% of the land around St. Mary's since 1986 (last in 2023); at low, it neither helps nor hurts the grade.
Is radon a problem in St. Mary's?
Around St. Mary's, 99 survey homes were tested and 2% came in over 200 Bq/m³, a guide to the area, not to any one home.
How big is the earthquake risk in St. Mary's?
About $0.017 a year per $1,000 of building value, NRCan’s long-run expectation for St. Mary's.
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).