Photo: Silver Dovelet · CC BY-SA 3.0Hazard risk in Stouffville is lower than in 92% of Canadian towns
Wildfire isn’t Stouffville’s worry: 0% of the land within 25 km burned since 1986 (0.001% a year). NRCan expects $0.024 of shaking damage a year per $1,000 of buildings in Stouffville, near the typical $0.030. In Health Canada’s survey, just 0% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Hazard risk gives Stouffville a grade of A; its wildfire band pulls it down.
What stands out about Stouffville’s hazards
Four national sources, each read for Stouffville: earthquakes, radon, past fires and flood studies.
What Stouffville faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Stouffville grades A for hazard risk
Two inputs always count for Stouffville, earthquakes and radon; the third, wildfire, counts only against a town.
Its place: #36 of 866 in Ontario and #288 of 2,589 Canadian towns.
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 Stouffville: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Stouffville’s residents live, and the fuel next to their homes.
At 0.001% of the land a year, Stouffville’s burn rate is in the low band; the typical Canadian town sees 0.000%.
Since 1986 the nearest fire to Stouffville’s homes came within 12 km, never inside 5 km.
About as much forest grows next to Stouffville’s homes (11% within 5 km) as across 25 km (11%).
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 Ontario · highest of 871
Stouffville ranks 83rd of the 871 towns in Ontario for burn rate, at 0.001% a year; Sioux Lookout leads with 0.16%.
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.
Beside 2,610 Canadian towns, Stouffville reads low, with 92% of them; only 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.
2 flood studies cover Stouffville, the newest from Toronto Regional Conservation Authority
Flood studies whose area touches Stouffville, from NRCan’s inventory, each linked to its owner.
2 studies on the inventory touch Stouffville, the newest Toronto Regional Conservation Authority’s from 2021, and their areas can be large, so they say maps exist, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| Toronto Floodline Consolidation | Toronto Regional Conservation Authority | 2021 | final |
| Duffins Creek | Toronto and Region Conservation Authority | 2020 | final |
Towns with a flood study on file
Flood maps are common in Ontario: 69% of towns have one, against 58% nationally, and Stouffville is among them.
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 Stouffville.
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 Stouffville $0.024 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.
Earthquake losses in Stouffville, $0.024 per $1,000, are in line with the typical $0.030 (0.8 times).
Shaking damage a year per $1,000 of building value
Below the middle in Ontario: Stouffville’s $0.024 against a median of $0.043; Alexandria has $0.21.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Neither high nor low for Canada: 54% of the 2,611 towns expect more damage than Stouffville.
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 Stouffville’s 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).
Radon runs low around Stouffville: 0% of tested homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Source area for radon tests: the York Regional Health Unit
Radon runs below the typical Canadian town (6.6%) in Stouffville’s area, at 0%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
The median in Ontario is 4% over 200 Bq/m³; around Stouffville it is 0%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Stouffville is in the lowest band, with 37% of Canada’s 2,611 towns: under 5% of tests over the guideline, while 63% have more.
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 Stouffville 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 Stouffville
Alerts for Stouffville 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 Stouffville 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 Stouffville’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Stouffville | Low | $0.024 | 0% | Yes |
| Greensborough 19,270 · 8.5 km | Low | $0.034 | 0% | Yes |
| Upper Cornell 8,304 · 8.6 km | Low | $0.034 | 0% | Yes |
| Wismer Commons 20,591 · 8.7 km | Low | $0.034 | 0% | Yes |
| Mount Joy 8,345 · 9.6 km | Low | $0.034 | 0% | Yes |
| Cornell 22,014 · 9.7 km | Low | $0.034 | 0% | Yes |
| Berczy Village 22,149 · 9.9 km | Low | $0.034 | 0% | Yes |
Among its neighbours Stouffville has the most fire on record (low); Upper Cornell follows (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Stouffville faces
What to do about the hazards Stouffville 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
- Wildfire counts one way. Wildfire is read from the national burned-area record around Stouffville’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Flood studies aren’t flood zones. A study’s area can be a whole watershed or province, so being on the inventory says a map exists, not that a home in Stouffville floods.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Stouffville’s figure is its subdivision’s.
- Radon is a survey. The radon share comes from about 14,000 long-term home tests in 2009–2011, pooled for now by the 2007 health region Stouffville sits in.
Questions about flooding and hazards in Stouffville
Is Stouffville at risk of wildfire?
Fire has reached 0% of the land around Stouffville since 1986 (last in 2006); at low, it neither helps nor hurts the grade.
How is Stouffville’s Hazard risk Grade worked out?
Stouffville’s Hazard risk grade is A, built on earthquakes and radon with a one-sided wildfire input.
Does Stouffville flood?
Stouffville’s area has been studied for flooding, and the owner’s map shows which streets lie in a zone; the grade leaves flood out.
Is radon a problem in Stouffville?
Around Stouffville, 95 survey homes were tested and 0% came in over 200 Bq/m³, a guide to the area, not to any one home.
How big is the earthquake risk in Stouffville?
About $0.024 a year per $1,000 of building value, NRCan’s long-run expectation for Stouffville.
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).