Photo: Pierre Bona · CC BY-SA 3.0A flood study covers Shefford: 1 on the national inventory, the newest from Gouvernement du Québec
Wildfire isn’t Shefford’s worry: 0% of the land within 25 km burned since 1986 (0.000% a year). Seismic risk in Shefford sits near the middle: $0.052 of expected damage per $1,000 of buildings a year, the typical town $0.030. About as many homes carry radon around Shefford as elsewhere, 8.2% over the guideline where the typical town has 6.6%. Shefford grades C+ for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Shefford’s hazards
For Shefford, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Shefford faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Shefford: C+
For Shefford, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #112 of 507 in Quebec and #1,812 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 Shefford: 0% of the land within 25 km burned since 1986, 0% within 5 km
Past fire around Shefford’s homes, from the national burned-area record, with the fuel within 5 km.
Forty years of fire maps put Shefford at 0.000% a year, low next to the typical Canadian town’s 0.000%.
No fire has burned within 5 km of Shefford’s homes since 1986; the nearest burn is 18 km away.
Near or far, forest fuel covers a similar share around Shefford: 16% within 5 km and 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
Mistissini has the highest burn rate in Quebec, 0.31% a year; around Shefford, as around 144 of the 513 towns, it rounds to zero.
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 holds 92% of Canada’s 2,610 towns, and Shefford sits at its very bottom; only 7.5% are above it.
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.
Shefford is on the flood map inventory: 1 study, by Gouvernement du Québec
What Canada’s Flood Map Inventory lists for Shefford: who studied flooding and where to see their maps.
Gouvernement du Québec studied flooding in an area that includes Shefford (1991); open its map to see which streets lie in a flood zone.
| Study | By | Year | Status |
|---|---|---|---|
| Waterloo | Gouvernement du Québec | 1991 | final |
Towns with a flood study on file
Shefford is one of the 45% of towns in Quebec with a flood study on file, fewer than Canada’s 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 Shefford 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 Shefford $0.052 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
At $0.052 per $1,000, Shefford’s earthquake risk is about the typical Canadian town’s ($0.030; 1.7 times).
Shaking damage a year per $1,000 of building value
Shefford’s $0.052 sits under the median in Quebec, $0.14, and well under La Pocatière’s $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.
Shefford sits above most of Canada’s 2,611 towns on earthquake risk; 30% 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).
For Shefford 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).
8.2% of homes tested around Shefford are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · The radon tests numbers here cover the Monteregie health region
Shefford’s area, at 8.2%, is close to the 6.6% of the typical Canadian town.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon around Shefford is ordinary for towns in Quebec: 8.2%, beside a median of 8.2%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Radon tops the guideline in a modest share of homes around Shefford, a band holding 37% of Canada’s 2,611 towns; 26% 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.
Neighbouring homes in Shefford 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 Shefford
Alerts for Shefford 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 Shefford 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)
How Shefford’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 |
|---|---|---|---|---|
| Shefford | Low | $0.052 | 8.2% | Yes |
| Bromont 12,413 · 7.3 km | Low | $0.067 | 8.2% | Yes |
| Waterloo 5,714 · 8.3 km | Low | $0.051 | 8.2% | Yes |
| Granby 72,180 · 9.7 km | Low | $0.090 | 8.2% | None listed |
| Roxton Pond 4,884 · 12 km | Low | $0.071 | 8.2% | None listed |
| Saint-Joachim-de-Shefford 1,552 · 12 km | Low | $0.057 | 8.2% | Yes |
| Saint-Alphonse-de-Granby 3,545 · 13 km | Low | $0.10 | 8.2% | None listed |
None of the places around has more fire nearby than Shefford (low); Bromont comes closest (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Shefford faces
Practical steps for Shefford’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.
- 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
- 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 Shefford.
- 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 Shefford.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Shefford’s included.
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Shefford is its health region’s, the survey’s design unit.
Questions about flooding and hazards in Shefford
Does Shefford flood?
There is flood mapping for Shefford on the national inventory, each study linked to its owner’s map, none of them graded.
How is Shefford’s Hazard risk Grade worked out?
Hazard risk gives Shefford C+, weighing earthquakes and radon and counting wildfire only against it.
Is radon a problem in Shefford?
The area’s survey found 8.2% of 110 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Shefford.
How big is the earthquake risk in Shefford?
In NRCan’s seismic model, Shefford’s buildings lose $0.052 per $1,000 of value in an average year.
Is Shefford at risk of wildfire?
Some, but Shefford’s low band (0% of nearby land burned since 1986, latest 2025) is short of the level that counts.
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).