Photo: SimonP · CC BY-SA 3.0A flood study covers Dorset Park: 1 on the national inventory, the newest from Toronto Regional Conservation Authority
Fire has left almost no mark near Dorset Park: 0% of the land within 25 km since 1986, 0.001% a year. Seismic risk in Dorset Park sits near the middle: $0.043 of expected damage per $1,000 of buildings a year, the typical town $0.030. In Health Canada’s survey, just 2.7% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Dorset Park grades A− for hazard risk, with wildfire counted against it.
What stands out about Dorset Park’s hazards
Four national sources, each read for Dorset Park: earthquakes, radon, past fires and flood studies.
What Dorset Park faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Dorset Park: A−
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Dorset Park with little fire nearby would get no credit for it.
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. 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.
Few fires near Dorset Park: 0% within 5 km, 0% within 25 km
Past fire around Dorset Park’s homes, from the national burned-area record, with the fuel within 5 km.
A burn rate of 0.001% a year keeps Dorset Park in the low band (the typical Canadian town: 0.000%).
Nothing inside 5 km of Dorset Park’s homes has burned since 1986, and the nearest scar is 15 km off.
Little near Dorset Park’s homes can carry a forest fire; only 0.2% of the land within 5 km is forest fuel, and 2.9% 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
Dorset Park 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; Dorset Park 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 Dorset Park, from Toronto Regional Conservation Authority: 1 on the inventory
What Canada’s Flood Map Inventory lists for Dorset Park: who studied flooding and where to see their maps.
The flood study touching Dorset Park 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
Its flood study puts Dorset Park with 69% of towns in Ontario; Canada’s share is 58%.
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 Dorset Park’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 Dorset Park: $0.043 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
At $0.043 per $1,000, Dorset Park’s earthquake risk is about the typical Canadian town’s ($0.030; 1.4 times).
Shaking damage a year per $1,000 of building value
Typical for its province: Dorset Park 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.
Middle of the pack: 36% of Canada’s 2,611 towns have more earthquake risk than Dorset Park.
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 Dorset Park’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). · Earthquake risk: the city of Toronto
Radon runs low around Dorset Park: 2.7% of tested homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
Radon runs below the typical Canadian town (6.6%) in Dorset Park’s area, at 2.7%. Nobody publishes radon tests for Dorset Park alone, so this card uses the figure for the City of Toronto Health Unit.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs lower around Dorset Park than in most towns in Ontario: 2.7% against 4%.
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 Dorset Park; 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.
Basements, soil and how a house is sealed decide its radon, so in Dorset Park only a test can say.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Dorset Park
Environment and Climate Change Canada issues the weather alerts for Dorset Park; 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 Dorset Park, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Dorset Park
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Dorset Park | Low | $0.043 | 2.7% | Yes |
| Bendale-Glen Andrew 19,134 · 1.7 km | Low | $0.043 | 2.7% | Yes |
| Wexford/Maryvale 28,591 · 2.2 km | Low | $0.043 | 2.7% | Yes |
| Bendale South 10,885 · 2.5 km | Low | $0.043 | 2.7% | Yes |
| Ionview 13,382 · 3.0 km | Low | $0.043 | 2.7% | Yes |
| Tam O'Shanter-Sullivan 27,526 · 3.1 km | Low | $0.043 | 2.7% | Yes |
| Agincourt South-Malvern West 24,438 · 3.1 km | Low | $0.043 | 2.7% | Yes |
Nowhere around Dorset Park burns more: Bendale-Glen Andrew, 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 Dorset Park faces
What to do about the hazards Dorset Park 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
- 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 Dorset Park until then.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Dorset Park’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Dorset Park’s figure is its subdivision’s.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Dorset Park without grading them.
Questions about flooding and hazards in Dorset Park
How big is the earthquake risk in Dorset Park?
NRCan’s model expects shaking to cost buildings in Dorset Park $0.043 a year for every $1,000 of their value, on average over many years.
Is radon a problem in Dorset Park?
In Health Canada’s survey, 2.7% of 74 homes tested in Dorset Park’s area were above 200 Bq/m³, though only a test tells you about one house.
How is Dorset Park’s Hazard risk Grade worked out?
Dorset Park’s Hazard risk grade is A−, built on earthquakes and radon with a one-sided wildfire input.
Is Dorset Park at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Dorset Park has burned since 1986, the last in 2001, a low band that leaves Risk alone.
Does Dorset Park flood?
A flood study covers Dorset Park on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
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).