Photo: Canmenwalker · CC BY 4.0Flood mapping exists for North Toronto: 1 on record, latest by Toronto Regional Conservation Authority
Wildfire isn’t North Toronto’s worry: 0% of the land within 25 km burned since 1986 (0.000% a year). Earthquake risk in North Toronto 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 North Toronto a grade of A−, from earthquakes and radon alone.
What stands out about North Toronto’s hazards
Four national sources, each read for North Toronto: earthquakes, radon, past fires and flood studies.
What North Toronto faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
North Toronto grades A− for hazard risk
For North Toronto, 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: Earthquake losses are a model’s expectation over many years, not a forecast for any one. The radon share rests on 74 home tests in the survey area, so a few homes move it. Small fires and grass fires are largely missing from the national burned-area record.
Wildfire is rare near North Toronto: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where North Toronto’s residents live, and the fuel next to their homes.
Low: the land around North Toronto burns at 0.000% a year, where the typical Canadian town sees 0.000%.
Land that isn’t forest covers nearly all the ground around North Toronto: forest fuel is 0.3% within 5 km and 1.3% 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, North Toronto 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.
Only 7.5% of Canada’s 2,610 towns are above the low band, which holds 92%; North Toronto, at a rounded zero, is far from them.
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 North Toronto (1 study)
Flood studies whose area touches North Toronto, from NRCan’s inventory, each linked to its owner.
The flood study touching North Toronto is Toronto Regional Conservation Authority’s, dated 2021; its own map shows the zones street by street.
| Study | By | Year | Status |
|---|---|---|---|
| Toronto Floodline Consolidation | Toronto Regional Conservation Authority | 2021 | final |
Towns with a flood study on file
Mapping in Ontario reaches 69% of towns, North Toronto included, beside 58% across Canada.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
The grade leaves flood out, since a study area says nothing about how many of North Toronto’s homes are at risk.
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 North Toronto: $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.
With $0.043 of shaking damage a year per $1,000, North Toronto is about even with the typical $0.030 (1.4 times).
Shaking damage a year per $1,000 of building value
North Toronto’s $0.043 is close to the median in Ontario, $0.043; Alexandria is highest 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.
North Toronto sits mid-range among Canada’s 2,611 towns: 36% expect more shaking damage.
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 North Toronto’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). · Data for earthquake risk covers the city of Toronto
Radon runs low around North Toronto: 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. · The radon tests numbers here cover the City of Toronto Health Unit
At 2.7% over the guideline, the area around North Toronto is under the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
North Toronto’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: North Toronto 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.
One home in North Toronto can be high while next door is low; a three-month test settles it.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for North Toronto
Environment and Climate Change Canada issues the weather alerts for North Toronto; 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. |
For fires near North Toronto, the national fire information system maps danger and active fires daily; local authorities give any evacuation order.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around North Toronto
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| North Toronto | Low | $0.043 | 2.7% | Yes |
| Mount Pleasant East 16,373 · 0.9 km | Low | $0.043 | 2.7% | Yes |
| Yonge-Eglinton 12,424 · 0.9 km | Low | $0.043 | 2.7% | Yes |
| South Eglinton-Davisville 23,380 · 0.9 km | Low | $0.043 | 2.7% | None listed |
| Lawrence Park South 15,018 · 1.1 km | Low | $0.043 | 2.7% | Yes |
| Bridle Path-Sunnybrook-York Mills 9,909 · 1.9 km | Low | $0.043 | 2.7% | Yes |
| Lawrence Park North 14,735 · 2.1 km | Low | $0.043 | 2.7% | Yes |
The fire record around Bridle Path-Sunnybrook-York Mills is a touch heavier than North Toronto’s, but the band is the same: low (here low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what North Toronto faces
Practical steps for North Toronto’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
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, North Toronto takes its 2007 health region’s share.
- Wildfire counts one way. Wildfire is read from the national burned-area record around North Toronto’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Flood studies aren’t flood zones. The flood inventory points to maps; it is incomplete and not the official source, so ask the municipality about any street in North Toronto.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; North Toronto’s figure is its subdivision’s.
Questions about flooding and hazards in North Toronto
How big is the earthquake risk in North Toronto?
Expected earthquake damage in North Toronto comes to $0.043 a year for each $1,000 that buildings are worth.
Is radon a problem in North Toronto?
2.7% of the 74 homes Health Canada tested around North Toronto topped the guideline; your own house needs its own test.
Is North Toronto at risk of wildfire?
Very little by the national record: North Toronto’s band is low, with 0% of the land within 25 km burned since 1986, so wildfire doesn’t change its grade.
How is North Toronto’s Hazard risk Grade worked out?
North Toronto’s Hazard risk grade is A−, built on earthquakes and radon with a one-sided wildfire input.
Does North Toronto flood?
The inventory lists a study touching North Toronto; whether a given street floods is on that map, not in the grade.
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).