Photo: Silver Dovelet · CC BY-SA 4.0Few places are as safe from hazards as Steeles Corners: it beats 88% of Canadian towns
Around Steeles Corners, wildfire is practically absent from the record: 0% within 25 km since 1986, 0.001% a year. NRCan expects $0.034 of shaking damage a year per $1,000 of buildings in Steeles Corners, near the typical $0.030. Radon is lower than usual: 0% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Hazard risk gives Steeles Corners a grade of A; its wildfire band pulls it down.
What stands out about Steeles Corners’s hazards
Four national sources, each read for Steeles Corners: earthquakes, radon, past fires and flood studies.
What Steeles Corners faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Steeles Corners grades A for hazard risk
Earthquake risk and radon make Steeles Corners’ grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
Its place: #165 of 866 in Ontario and #484 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 Steeles Corners: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Steeles Corners’ residents live, and the fuel next to their homes.
The yearly burn rate around Steeles Corners is 0.001%, low beside 0.000% for the typical Canadian town.
Steeles Corners’ homes have had no fire within 5 km since 1986; the closest was 21 km away.
Forest makes up 0.1% of the land within 5 km of Steeles Corners and 3.3% within 25 km, little for a forest fire to run through.
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
The land around Steeles Corners burns at 0.001% a year, the 83rd highest rate of 871 towns in Ontario; Sioux Lookout tops it at 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.
Some fire is mapped around Steeles Corners, but not enough to leave the low band, where 92% of Canada’s 2,610 towns are; 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 Steeles Corners (1 study)
Flood studies whose area touches Steeles Corners, from NRCan’s inventory, each linked to its owner.
One study on the inventory touches Steeles Corners, Toronto Regional Conservation Authority’s from 2021, and its area can be large, so it says a map exists, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| Toronto Floodline Consolidation | Toronto Regional Conservation Authority | 2021 | final |
Towns with a flood study on file
69% of towns in Ontario have a flood study, more than Canada’s 58%; Steeles Corners has one too.
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 Steeles Corners’ 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 Steeles Corners: $0.034 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.
Earthquake losses in Steeles Corners, $0.034 per $1,000, are in line with the typical $0.030 (1.1 times).
Shaking damage a year per $1,000 of building value
Below the middle in Ontario: Steeles Corners’ $0.034 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.
Steeles Corners’ earthquake risk lands near the centre of Canada’s range; 46% 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).
The loss is to Steeles Corners’ 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). · Not measured by town: earthquake risk (the city of Markham)
Radon runs low around Steeles Corners: 0% of tested homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Shared with the rest of the York Regional Health Unit: radon tests
Radon runs below the typical Canadian town (6.6%) in Steeles Corners’ area, at 0%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Steeles Corners’ area, at 0%, 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: Steeles Corners 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.
A survey sample isn’t a map: any home in Steeles Corners 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 Steeles Corners
Environment and Climate Change Canada issues the weather alerts for Steeles Corners; 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 Steeles Corners, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Steeles Corners’ neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Steeles Corners | Low | $0.034 | 0% | Yes |
| Thornhill 17,940 · 1.5 km | Low | $0.028 | 0% | Yes |
| Newtonbrook East 15,996 · 1.9 km | Low | $0.043 | 2.7% | Yes |
| Langstaff 8,147 · 1.9 km | Low | $0.034 | 0% | Yes |
| Thornlea 20,872 · 2.8 km | Low | $0.034 | 0% | Yes |
| Newtonbrook West 23,978 · 2.9 km | Low | $0.043 | 2.7% | Yes |
| Bayview Woods-Steeles 12,499 · 3.0 km | Low | $0.043 | 2.7% | Yes |
Nowhere around Steeles Corners burns more: Thornhill, the closest rival, is low to its low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Steeles Corners faces
Practical steps for Steeles Corners’ 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. Flood studies cover areas of every size, which is why the page lists them for Steeles Corners without grading them.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Steeles Corners’ homes since 1986, a history of fire that may lower Risk but never raises it.
- Radon is a survey. Radon figures pool the survey’s home tests by area: postal areas once their boundaries arrive, the 2007 health region around Steeles Corners until then.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Steeles Corners’ figure is its subdivision’s.
Questions about flooding and hazards in Steeles Corners
How big is the earthquake risk in Steeles Corners?
About $0.034 a year per $1,000 of building value, NRCan’s long-run expectation for Steeles Corners.
How is Steeles Corners’s Hazard risk Grade worked out?
Hazard risk gives Steeles Corners A, weighing earthquakes and radon and counting wildfire only against it.
Does Steeles Corners flood?
A flood study covers Steeles Corners on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
Is Steeles Corners at risk of wildfire?
Some, but Steeles Corners’ low band (0% of nearby land burned since 1986, latest 2001) is short of the level that counts.
Is radon a problem in Steeles Corners?
The area’s survey found 0% of 95 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Steeles Corners.
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).