Photo: Geo Swan from Toronto, Canada · CC0A flood study covers Church-Wellesley: 1 on the national inventory, the newest from Toronto Regional Conservation Authority
The national fire record shows next to nothing around Church-Wellesley, 0% of the land within 25 km since 1986 (0.000% a year). Shaking is about as much of a worry in Church-Wellesley as in most places, at $0.043 a year per $1,000 of building value ($0.030 typical). In Health Canada’s survey, just 2.7% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Church-Wellesley grades A− for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Church-Wellesley’s hazards
For Church-Wellesley, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Church-Wellesley faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Church-Wellesley grades A− for hazard risk
For Church-Wellesley, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #285 of 866 in Ontario and #700 of 2,589 Canadian towns.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. The radon share rests on 74 home tests in the survey area, so a few homes move it. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Wildfire is rare near Church-Wellesley: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Church-Wellesley’s residents live, and the fuel next to their homes.
Around Church-Wellesley fire takes 0.000% of the land in a typical year, the typical Canadian town 0.000%, which is low.
Only 0.8% of the land within 25 km of Church-Wellesley is forest fuel, and 0.7% close in.
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
To three decimals the burn rate around Church-Wellesley is zero, as for 638 of the 871 towns in Ontario, while Sioux Lookout reaches 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.
Like most of Canada’s 2,610 towns (92%), Church-Wellesley is in the low band, with a burn rate of zero to three decimals; 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.
Toronto Regional Conservation Authority has mapped flooding for Church-Wellesley (1 study)
Flood studies whose area touches Church-Wellesley, from NRCan’s inventory, each linked to its owner.
For Church-Wellesley the inventory points to Toronto Regional Conservation Authority’s 2021 study, whose map is the one to check.
| Study | By | Year | Status |
|---|---|---|---|
| Toronto Floodline Consolidation | Toronto Regional Conservation Authority | 2021 | final |
Towns with a flood study on file
Church-Wellesley is one of the 69% of towns in Ontario with a flood study on file; across Canada it 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 Church-Wellesley.
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.
Expected shaking damage in Church-Wellesley: $0.043 a year per $1,000
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
1.4 times the typical $0.030: Church-Wellesley’s $0.043 is ordinary.
Shaking damage a year per $1,000 of building value
Typical for its province: Church-Wellesley at $0.043 beside a median in Ontario of $0.043, with Alexandria on top at $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.
Church-Wellesley’s earthquake risk lands near the centre of Canada’s range; 36% 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).
Only shaking damage to buildings in Church-Wellesley is counted; landslides, liquefaction, tsunami and fire after a quake aren’t.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean). · Earthquake risk published for the city of Toronto, not by town
Little radon around Church-Wellesley: 2.7% of area homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Radon tests for the City of Toronto Health Unit
At 2.7% over the guideline, the area around Church-Wellesley is under the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Church-Wellesley’s area, at 2.7%, is below the median in Ontario (4%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Few tests over the guideline: Church-Wellesley shares the bottom band with 37% of Canada’s 2,611 towns, below the other 63%.
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 Church-Wellesley 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 Church-Wellesley
Alerts for Church-Wellesley 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. |
Fire danger and active fires near Church-Wellesley are mapped daily by the Canadian Wildland Fire Information System; evacuation orders come from the municipality or province.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Church-Wellesley
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Church-Wellesley | Low | $0.043 | 2.7% | Yes |
| Bay-Cloverhill 17,591 · 0.4 km | Low | $0.043 | 2.7% | Yes |
| North St.James Town 18,733 · 0.8 km | Low | $0.043 | 2.7% | Yes |
| Cabbagetown-South St.James Town 11,205 · 1.1 km | Low | $0.043 | 2.7% | Yes |
| Yonge-Bay Corridor 12,888 · 1.1 km | Low | $0.043 | 2.7% | None listed |
| Downtown Yonge East 18,251 · 1.4 km | Low | $0.043 | 2.7% | None listed |
| Annex 30,705 · 1.6 km | Low | $0.043 | 2.7% | Yes |
The neighbour with the most fire is Bay-Cloverhill (low), still no more than Church-Wellesley (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Church-Wellesley faces
Practical steps for Church-Wellesley’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. 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 Church-Wellesley floods.
- 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 Church-Wellesley sits in.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Church-Wellesley’s census subdivision (a neighbourhood shows its city’s).
- Wildfire counts one way. For Church-Wellesley, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
Questions about flooding and hazards in Church-Wellesley
Is radon a problem in Church-Wellesley?
2.7% of the 74 homes Health Canada tested around Church-Wellesley topped the guideline; your own house needs its own test.
How big is the earthquake risk in Church-Wellesley?
About $0.043 a year per $1,000 of building value, NRCan’s long-run expectation for Church-Wellesley.
How is Church-Wellesley’s Hazard risk Grade worked out?
Church-Wellesley’s Hazard risk grade is A−, built on earthquakes and radon with a one-sided wildfire input.
Is Church-Wellesley at risk of wildfire?
Hardly at all on record: 0% of the land within 25 km of Church-Wellesley since 1986, a low band, though small grass fires aren’t mapped.
Does Church-Wellesley flood?
Church-Wellesley’s area has been studied for flooding, and the owner’s map shows which streets lie in a zone; the grade leaves flood out.
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).