Photo: ChadPerez49 · CC BY-SA 3.0Few places are as safe from hazards as Wismer Commons: it beats 88% of Canadian towns
Wildfire isn’t Wismer Commons’ worry: 0% of the land within 25 km burned since 1986 (0.001% a year). NRCan expects $0.034 of shaking damage a year per $1,000 of buildings in Wismer Commons, near the typical $0.030. In Health Canada’s survey, just 0% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Wismer Commons grades A for hazard risk, with wildfire counted against it.
What stands out about Wismer Commons’s hazards
For Wismer Commons, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Wismer Commons faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Wismer Commons: A
The grade weighs Wismer Commons’ seismic risk and radon equally, and wildfire is one-sided: a high band counts against a town, a low one earns nothing.
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 Wismer Commons: 0% within 5 km, 0% within 25 km
Fires mapped since 1986 around where Wismer Commons’ residents live, and the fuel next to their homes.
Wismer Commons burns at 0.001% a year, low against 0.000% for the typical Canadian town.
Since 1986 the nearest fire to Wismer Commons’ homes came within 9.9 km, never inside 5 km.
Close to Wismer Commons there is little to burn (1.6% forest fuel within 5 km), but 8.3% of the land within 25 km is forest.
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
In the top quarter in Ontario: Wismer Commons ranks 83rd of 871 at 0.001% a year, with Sioux Lookout first 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.
7.5% of Canada’s 2,610 towns burn fast enough to rank moderate or above; Wismer Commons 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.
A flood study covers Wismer Commons, from Toronto Regional Conservation Authority: 1 on the inventory
Flood studies whose area touches Wismer Commons, from NRCan’s inventory, each linked to its owner.
One study on the inventory touches Wismer Commons, 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
Wismer Commons is one of the 69% of towns in Ontario with a flood study on file; across Canada it is 58%.
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 Wismer Commons.
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 Wismer Commons: $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.
Earthquake losses in Wismer Commons, $0.034 per $1,000, are in line with the typical $0.030 (1.1 times).
Wismer Commons 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
The typical town in Ontario expects $0.043 a year in shaking damage; Wismer Commons expects less, $0.034, and Alexandria the most, $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.
Wismer Commons’ 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).
Only shaking damage to buildings in Wismer Commons 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).
0% of homes tested around Wismer Commons are over the radon guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Measured across the York Regional Health Unit: radon tests
At 0% over the guideline, the area around Wismer Commons is under the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Against the typical town in Ontario (4%), the area around Wismer Commons has fewer high tests: 0%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
The quietest radon band, under 5%, holds 37% of Canada’s 2,611 towns and Wismer Commons; 63% sit higher.
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 Wismer Commons 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 Wismer Commons
Environment and Climate Change Canada issues the weather alerts for Wismer Commons; 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 Wismer Commons, 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 Wismer Commons’ neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Wismer Commons | Low | $0.034 | 0% | Yes |
| Mount Joy 8,345 · 1.6 km | Low | $0.034 | 0% | Yes |
| Greensborough 19,270 · 1.8 km | Low | $0.034 | 0% | Yes |
| Quantztown 13,146 · 2.0 km | Low | $0.034 | 0% | Yes |
| Berczy Village 22,149 · 2.3 km | Low | $0.034 | 0% | Yes |
| Markham Village 10,319 · 2.4 km | Low | $0.034 | 0% | Yes |
| Upper Cornell 8,304 · 3.6 km | Low | $0.034 | 0% | Yes |
Wismer Commons’ low band tops its neighbours; Mount Joy is next (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Wismer Commons faces
What to do about the hazards Wismer Commons 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
- Wildfire counts one way. For Wismer Commons, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Wismer Commons without grading them.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Wismer Commons’ census subdivision (a neighbourhood shows its city’s).
- 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 Wismer Commons until then.
Questions about flooding and hazards in Wismer Commons
Does Wismer Commons flood?
A flood study covers Wismer Commons on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
How big is the earthquake risk in Wismer Commons?
About $0.034 a year per $1,000 of building value, NRCan’s long-run expectation for Wismer Commons.
How is Wismer Commons’s Hazard risk Grade worked out?
Hazard risk gives Wismer Commons A, weighing earthquakes and radon and counting wildfire only against it.
Is radon a problem in Wismer Commons?
In Health Canada’s survey, 0% of 95 homes tested in Wismer Commons’ area were above 200 Bq/m³, though only a test tells you about one house.
Is Wismer Commons at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Wismer Commons has burned since 1986, the last in 2001, a low band that leaves Risk alone.
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).