Photo: Earth Science and Remote Sensing Unit , Lyndon B. Johnson Space Center · Public domain17% of homes tested in Saint Marys’ area are above the radon guideline
Wildfire is rare near Saint Marys: 0.8% of the land within 25 km has burned since 1986, a burn rate of 0.04% a year. Earthquake risk in Saint Marys is ordinary: NRCan’s model puts building losses at $0.034 a year per $1,000 of value, close to the typical town’s $0.030. Hazard risk gives Saint Marys a grade of C; its wildfire band pulls it down.
What stands out about Saint Marys’s hazards
Four national sources, each read for Saint Marys: earthquakes, radon, past fires and flood studies.
What Saint Marys faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Saint Marys grades C for hazard risk
Two inputs always count for Saint Marys, earthquakes and radon; the third, wildfire, counts only against a town.
Its place: #13 of 60 in New Brunswick and #2,236 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Small fires and grass fires are largely missing from the national burned-area record.
Few fires near Saint Marys: 0% within 5 km, 0.8% within 25 km
Past fire around Saint Marys’ homes, from the national burned-area record, with the fuel within 5 km.
Low by Canadian standards: 0.04% of the land a year around Saint Marys, 0.000% for the typical Canadian town.
The 5 km ring around Saint Marys’ homes is clear of burns since 1986, the nearest 19 km out.
Near or far, forest fuel covers a similar share around Saint Marys: 80% within 5 km and 81% 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 New Brunswick · highest of 60
Saint Marys ranks 11th of the 60 towns in New Brunswick for burn rate, at 0.04% a year; Tracadie leads with 0.28%.
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 Saint Marys, 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.
Service New Brunswick - GeoNB has mapped flooding for Saint Marys (1 study)
What Canada’s Flood Map Inventory lists for Saint Marys: who studied flooding and where to see their maps.
For Saint Marys the inventory points to Service New Brunswick - GeoNB’s 2020 study, whose map is the one to check.
| Study | By | Year | Status |
|---|---|---|---|
| Inland Flood Mapping in New Brunswick and Updated Sea-Level Rise and Flooding Estimates for New Brunswick Coastal Sections 2020 | Service New Brunswick - GeoNB | 2020 | final |
Towns with a flood study on file
Its flood study puts Saint Marys with 93% of towns in New Brunswick; Canada’s share is 58%.
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 Saint Marys.
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.
Ordinary seismic risk in Saint Marys: $0.034 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Nothing unusual about Saint Marys’ ground: $0.034 against a typical $0.030, 1.1 times.
Shaking damage a year per $1,000 of building value
Typical for its province: Saint Marys at $0.034 beside a median in New Brunswick of $0.036, with St. Stephen on top at $0.16.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Middle of the pack: 46% of Canada’s 2,611 towns have more earthquake risk than Saint Marys.
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 Saint Marys’ 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).
17% of homes tested around Saint Marys are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
At 17% over the guideline, the area around Saint Marys beats the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Ordinary for towns in New Brunswick at 17% over 200 Bq/m³ (20% is the median), the area around Saint Marys had 7.1% over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
4.6% of Canada’s 2,611 towns have a higher share of homes over 200 Bq/m³ than Saint Marys, in the 10–20% band with 22%.
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.
Basements, soil and how a house is sealed decide its radon, so in Saint Marys only a test can say.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Not measured by town: radon tests (the Region 3 health region)
Weather and fire alerts for Saint Marys
Alerts for Saint Marys 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. |
Alert Ready carries evacuation orders for Saint Marys to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Saint Marys’ neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Saint Marys | Low | $0.034 | 17% | Yes |
| Devon 30 1,105 · 11 km | Low | $0.030 | 17% | Yes |
| Fredericton 74,655 · 13 km | Moderate | $0.039 | 17% | Yes |
| Maugerville 1,808 · 15 km | Moderate | $0.044 | 17% | Yes |
| Douglas 6,840 · 18 km | Low | $0.036 | 17% | Yes |
Fire is heaviest around Maugerville (moderate), against low for Saint Marys.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Saint Marys faces
What to do about the hazards Saint Marys 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
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Saint Marys is its health region’s, the survey’s design unit.
- 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 Saint Marys.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Saint Marys’ 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 Saint Marys’.
Questions about flooding and hazards in Saint Marys
Does Saint Marys flood?
There is flood mapping for Saint Marys on the national inventory, each study linked to its owner’s map, none of them graded.
How is Saint Marys’s Hazard risk Grade worked out?
Hazard risk gives Saint Marys C, weighing earthquakes and radon and counting wildfire only against it.
Is Saint Marys at risk of wildfire?
Less than most of Canada: 0.8% of the land within 25 km of Saint Marys has burned since 1986, the last in 2025, a low band that leaves Risk alone.
How big is the earthquake risk in Saint Marys?
NRCan’s model expects shaking to cost buildings in Saint Marys $0.034 a year for every $1,000 of their value, on average over many years.
Is radon a problem in Saint Marys?
In Health Canada’s survey, 17% of 112 homes tested in Saint Marys’ area were above 200 Bq/m³, though only a test tells you about one house.
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).