Photo: Joli Rumi · CC BY-SA 4.0Hazards in Yonge-Bay Corridor are mild: low wildfire and earthquake risk, and 2.7% of area homes above the radon guideline
The burned-area map is nearly blank around Yonge-Bay Corridor, 0% within 25 km since 1986, 0.000% a year. NRCan expects $0.043 of shaking damage a year per $1,000 of buildings in Yonge-Bay Corridor, near the typical $0.030. Hazard risk gives Yonge-Bay Corridor a grade of A−, from earthquakes and radon alone.
What stands out about Yonge-Bay Corridor’s hazards
Four national sources, each read for Yonge-Bay Corridor: earthquakes, radon, past fires and flood studies.
What Yonge-Bay Corridor faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Yonge-Bay Corridor: A−
Two inputs always count for Yonge-Bay Corridor, earthquakes and radon; the third, wildfire, counts only against a town.
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. Only 74 homes were tested in the survey area, so the radon share is rough. Small fires and grass fires are largely missing from the national burned-area record.
Little of the land around Yonge-Bay Corridor has burned: 0% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where Yonge-Bay Corridor’s residents live, and the fuel next to their homes.
Forty years of fire maps put Yonge-Bay Corridor at 0.000% a year, low next to the typical Canadian town’s 0.000%.
Forest fuel is scarce around Yonge-Bay Corridor: 1.1% of the land within 5 km, 0.5% 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
Of the 871 towns in Ontario, 638 have a burn rate that rounds to zero, Yonge-Bay Corridor among them; Sioux Lookout leads at 0.16% a year.
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.
92% of Canada’s 2,610 towns are in the low band and 7.5% above it; Yonge-Bay Corridor is among the many where the yearly burn rate rounds to zero.
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.
The flood map inventory lists nothing for Yonge-Bay Corridor
Flood studies whose area touches Yonge-Bay Corridor, from NRCan’s inventory, each linked to its owner.
Canada’s Flood Map Inventory lists no study whose area touches Yonge-Bay Corridor, which doesn’t mean it has never been mapped.
Towns with a flood study on file
69% of towns in Ontario have a flood study, more than Canada’s 58%; Yonge-Bay Corridor is not yet one of them.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Nothing here counts toward Risk; the studies are pointers to the maps their owners keep for Yonge-Bay Corridor.
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.”
Expected shaking damage in Yonge-Bay Corridor: $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.
Yonge-Bay Corridor’s $0.043 is close to the typical town’s $0.030 (1.4 times as much).
Shaking damage a year per $1,000 of building value
Typical for its province: Yonge-Bay Corridor 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.
Yonge-Bay Corridor’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).
Roads, pipes and bridges aren’t in Yonge-Bay Corridor’s figure, nor landslides or tsunami: it is buildings and shaking.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean). · Area behind the earthquake risk figures: the city of Toronto
2.7% of homes tested around Yonge-Bay Corridor are over the radon guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
Radon runs below the typical Canadian town (6.6%) in Yonge-Bay Corridor’s area, at 2.7%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Fewer homes top the guideline around Yonge-Bay Corridor (2.7%) than in the typical town in Ontario (4%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Radon rarely tops the guideline around Yonge-Bay Corridor, as for 37% of Canada’s 2,611 towns; 63% see 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.
The share describes the area, not a house: in Yonge-Bay Corridor as anywhere, test to be sure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Radon tests published for the City of Toronto Health Unit, not by town
Weather and fire alerts for Yonge-Bay Corridor
Environment and Climate Change Canada issues the weather alerts for Yonge-Bay Corridor; Alert Ready carries the urgent ones to phones, radio and TV.
| 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. |
In fire season, check CWFIS for danger and active fires around Yonge-Bay Corridor, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Yonge-Bay Corridor
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Yonge-Bay Corridor | Low | $0.043 | 2.7% | None listed |
| Downtown Yonge East 18,251 · 0.6 km | Low | $0.043 | 2.7% | None listed |
| Bay-Cloverhill 17,591 · 1.0 km | Low | $0.043 | 2.7% | Yes |
| Kensington-Chinatown 18,597 · 1.1 km | Low | $0.043 | 2.7% | None listed |
| Church-Wellesley 22,415 · 1.1 km | Low | $0.043 | 2.7% | Yes |
| Moss Park 22,701 · 1.3 km | Low | $0.043 | 2.7% | Yes |
| Cabbagetown-South St.James Town 11,205 · 1.4 km | Low | $0.043 | 2.7% | Yes |
The neighbour with the most fire is Downtown Yonge East (low), still no more than Yonge-Bay Corridor (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Yonge-Bay Corridor faces
What to do about the hazards Yonge-Bay Corridor 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?
- Ask the municipality for flood maps.
- 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 Yonge-Bay Corridor floods.
- 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 Yonge-Bay Corridor’s.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Yonge-Bay Corridor’s homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- 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 Yonge-Bay Corridor sits in.
Questions about flooding and hazards in Yonge-Bay Corridor
Does Yonge-Bay Corridor flood?
Nothing is listed for Yonge-Bay Corridor on the national inventory (0); local maps may still exist with the municipality.
How big is the earthquake risk in Yonge-Bay Corridor?
About $0.043 a year per $1,000 of building value, NRCan’s long-run expectation for Yonge-Bay Corridor.
Is radon a problem in Yonge-Bay Corridor?
In Health Canada’s survey, 2.7% of 74 homes tested in Yonge-Bay Corridor’s area were above 200 Bq/m³, though only a test tells you about one house.
How is Yonge-Bay Corridor’s Hazard risk Grade worked out?
Hazard risk gives Yonge-Bay Corridor A−, weighing earthquakes and radon and counting wildfire only against it.
Is Yonge-Bay Corridor at risk of wildfire?
Hardly at all on record: 0% of the land within 25 km of Yonge-Bay Corridor since 1986, a low band, though small grass fires aren’t mapped.
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).