Photo: Canmenwalker · CC BY 4.0Flood mapping exists for West Hill: 1 on record, latest by Toronto Regional Conservation Authority
Around West Hill, wildfire is practically absent from the record: 0% within 25 km since 1986, 0.001% a year. Earthquake risk in West Hill is ordinary: NRCan’s model puts building losses at $0.043 a year per $1,000 of value, close to the typical town’s $0.030. Radon is lower than usual: 2.7% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Hazard risk gives West Hill a grade of A−; its wildfire band pulls it down.
What stands out about West Hill’s hazards
For West Hill, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What West Hill faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
West Hill grades A− for hazard risk
The grade weighs West Hill’s seismic risk and radon equally, and wildfire is one-sided: a high band counts against a town, a low one earns nothing.
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.
Little of the land around West Hill has burned: 0% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where West Hill’s residents live, and the fuel next to their homes.
In a typical year 0.001% of the land near West Hill burns; the typical Canadian town sees 0.000%, and both are low.
No fire has burned within 5 km of West Hill’s homes since 1986; the nearest burn is 9.7 km away.
Land that isn’t forest covers nearly all the ground around West Hill: forest fuel is 2.5% within 5 km and 4.1% 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 Ontario · highest of 871
At 0.001% a year, West Hill is near the top in Ontario: 83rd of 871, behind Sioux Lookout (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.
West Hill is in the low band with 92% of Canada’s 2,610 towns; 7.5% sit in moderate or 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.
West Hill is on the flood map inventory: 1 study, by Toronto Regional Conservation Authority
Flood studies whose area touches West Hill, from NRCan’s inventory, each linked to its owner.
Toronto Regional Conservation Authority holds the flood mapping that covers West Hill (2021), linked below.
| Study | By | Year | Status |
|---|---|---|---|
| Toronto Floodline Consolidation | Toronto Regional Conservation Authority | 2021 | final |
Towns with a flood study on file
Its flood study puts West Hill with 69% of towns in Ontario; 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 West Hill.
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 West Hill: $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: West Hill’s $0.043 is ordinary.
Behind earthquake risk sits data gathered across the city of Toronto, with West Hill one part of it.
Shaking damage a year per $1,000 of building value
Shaking damage around West Hill runs at $0.043 a year, near the $0.043 of the typical town in Ontario; 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: 36% of the 2,611 towns expect more damage than West Hill.
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).
What a quake does after the shaking, fire, landslides, tsunami, falls outside NRCan’s figure for West Hill.
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 West Hill: 2.7% 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, West Hill’s area has fewer, 2.7%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
The median in Ontario is 4% over 200 Bq/m³; around West Hill it is 2.7%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
West Hill 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.
Neighbouring homes in West Hill 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). · Radon tests: one figure for all of the City of Toronto Health Unit
Where to get warnings in West Hill
Alerts for West Hill 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 West Hill 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 West Hill’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| West Hill | Low | $0.043 | 2.7% | Yes |
| Guildwood 9,797 · 2.2 km | Low | $0.043 | 2.7% | Yes |
| Morningside 17,708 · 2.5 km | Low | $0.043 | 2.7% | Yes |
| Highland Creek 12,678 · 2.7 km | Low | $0.043 | 2.7% | Yes |
| Golfdale-Cedarbrae-Woburn 27,429 · 3.1 km | Low | $0.043 | 2.7% | Yes |
| Centennial Scarborough 13,453 · 3.2 km | Low | $0.043 | 2.7% | Yes |
| Scarborough Village 16,774 · 3.8 km | Low | $0.043 | 2.7% | Yes |
Among its neighbours West Hill has the most fire on record (low); Guildwood follows (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what West Hill faces
What to do about the hazards West Hill 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. The radon share comes from about 14,000 long-term home tests in 2009–2011, pooled for now by the 2007 health region West Hill sits in.
- 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 West Hill.
- 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 West Hill floods.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, West Hill’s included.
Questions about flooding and hazards in West Hill
Is radon a problem in West Hill?
In Health Canada’s survey, 2.7% of 74 homes tested in West Hill’s area were above 200 Bq/m³, though only a test tells you about one house.
How is West Hill’s Hazard risk Grade worked out?
West Hill grades A− for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Does West Hill flood?
West Hill’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 West Hill at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of West Hill has burned since 1986, the last in 2001, a low band that leaves Risk alone.
How big is the earthquake risk in West Hill?
About $0.043 a year per $1,000 of building value, NRCan’s long-run expectation for West Hill.
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).