Photo: Silver Dovelet · CC BY-SA 4.0Hazard risk in Langstaff is lower than in 88% of Canadian towns
The national fire record shows next to nothing around Langstaff, 0% of the land within 25 km since 1986 (0.001% a year). For earthquakes Langstaff is middling, $0.034 a year per $1,000 against $0.030 for the typical town. Fewer homes than usual carry radon here, 0% over the guideline where the typical town has 6.6%. Langstaff grades A for hazard risk, with wildfire counted against it.
What stands out about Langstaff’s hazards
For Langstaff, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Langstaff faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Langstaff: A
Seismic risk and radon set Langstaff’s grade, wildfire can drag it down, and flood mapping stays out of it.
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. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Few fires near Langstaff: 0% within 5 km, 0% within 25 km
Fires mapped since 1986 around where Langstaff’s residents live, and the fuel next to their homes.
Low by Canadian standards: 0.001% of the land a year around Langstaff, 0.000% for the typical Canadian town.
Nothing inside 5 km of Langstaff’s homes has burned since 1986, and the nearest scar is 21 km off.
Around Langstaff the forest is thin or far off: 0.3% of the land within 5 km and 3.7% within 25 km is forest fuel.
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
Langstaff ranks 83rd of the 871 towns in Ontario for burn rate, at 0.001% a year; Sioux Lookout leads with 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.
7.5% of Canada’s 2,610 towns burn fast enough to rank moderate or above; Langstaff stays low, with 92%.
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 Langstaff (1 study)
Flood studies whose area touches Langstaff, from NRCan’s inventory, each linked to its owner.
The flood study touching Langstaff 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, Langstaff 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 Langstaff’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.
Ordinary seismic risk in Langstaff: $0.034 per $1,000 of buildings a year
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
Nothing unusual about Langstaff’s ground: $0.034 against a typical $0.030, 1.1 times.
Langstaff doesn’t get its own earthquake risk figures; the ones here come from the city of Markham.
Shaking damage a year per $1,000 of building value
At $0.034, Langstaff is below the typical town 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.
Langstaff sits mid-range among Canada’s 2,611 towns: 46% 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).
Only shaking damage to buildings in Langstaff 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).
Little radon around Langstaff: 0% 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 York Regional Health Unit
Where the typical Canadian town has 6.6% of homes over the guideline, Langstaff’s area has fewer, 0%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs lower around Langstaff than in most towns in Ontario: 0% against 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: Langstaff 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 Langstaff 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 Langstaff
Environment and Climate Change Canada issues the weather alerts for Langstaff; 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 Langstaff, 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)
How Langstaff’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Langstaff | Low | $0.034 | 0% | Yes |
| Steeles Corners 9,468 · 1.9 km | Low | $0.034 | 0% | Yes |
| Thornlea 20,872 · 2.3 km | Low | $0.034 | 0% | Yes |
| Thornhill 17,940 · 2.4 km | Low | $0.028 | 0% | Yes |
| Beverley Glen 38,720 · 3.6 km | Low | $0.028 | 0% | Yes |
| Newtonbrook East 15,996 · 3.8 km | Low | $0.043 | 2.7% | Yes |
| Thornhill Woods 13,237 · 3.9 km | Low | $0.028 | 0% | Yes |
Nowhere around Langstaff burns more: Steeles Corners, 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 Langstaff faces
Practical steps for Langstaff’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 Langstaff floods.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Langstaff’s included.
- 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 Langstaff 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 Langstaff.
Questions about flooding and hazards in Langstaff
How is Langstaff’s Hazard risk Grade worked out?
Langstaff grades A for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is radon a problem in Langstaff?
0% of the 95 homes Health Canada tested around Langstaff topped the guideline; your own house needs its own test.
How big is the earthquake risk in Langstaff?
Expected earthquake damage in Langstaff comes to $0.034 a year for each $1,000 that buildings are worth.
Is Langstaff at risk of wildfire?
Not much by Canadian standards: Langstaff’s band is low, with 0% of the land within 25 km burned since 1986 (last in 2001), so wildfire doesn’t change its grade.
Does Langstaff flood?
Langstaff’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).