Photo: Dillan Payne · CC BY-SA 4.0North Riverdale is on Canada’s flood inventory: 1 listed, led by Toronto Regional Conservation Authority
Fire has left almost no mark near North Riverdale: 0% of the land within 25 km since 1986, 0.000% a year. Earthquake risk in North Riverdale 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 Riverdale a grade of A−, from earthquakes and radon alone.
What stands out about North Riverdale’s hazards
Four national sources, each read for North Riverdale: earthquakes, radon, past fires and flood studies.
What North Riverdale faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in North Riverdale: A−
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like North Riverdale 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. Only 74 homes were tested in the survey area, so the radon share is rough. Small fires and grass fires are largely missing from the national burned-area record.
Wildfire is rare near North Riverdale: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where North Riverdale’s residents live, and the fuel next to their homes.
Next to the typical Canadian town (0.000% a year), North Riverdale’s 0.000% is in the low band.
Only 1% of the land within 25 km of North Riverdale is forest fuel, and 0.8% close in.
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
Near-zero burning puts North Riverdale with 638 of the 871 towns in Ontario, far below Sioux Lookout 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.
Most of the country’s 2,610 towns are low-band (92%, against 7.5% above); around North Riverdale, burning rounds to zero.
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.
North Riverdale is on the flood map inventory: 1 study, by Toronto Regional Conservation Authority
Flood studies whose area touches North Riverdale, from NRCan’s inventory, each linked to its owner.
The flood study touching North Riverdale 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 North Riverdale 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 North Riverdale’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 North Riverdale: $0.043 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.
At $0.043 per $1,000, North Riverdale’s earthquake risk is about the typical Canadian town’s ($0.030; 1.4 times).
North Riverdale doesn’t get its own earthquake risk figures; the ones here come from the city of Toronto.
Shaking damage a year per $1,000 of building value
About level with the typical town in Ontario: North Riverdale’s $0.043 against $0.043; Alexandria reaches $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 Riverdale 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 Riverdale’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).
Radon runs low around North Riverdale: 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. · Radon tests for the City of Toronto Health Unit
North Riverdale’s area, at 2.7%, is below the 6.6% of the typical Canadian town, though any one home can still be high.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs lower around North Riverdale 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.
North Riverdale is in the lowest band, with 37% of Canada’s 2,611 towns: under 5% of tests over the guideline, while 63% have more.
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 North Riverdale 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 North Riverdale
Environment and Climate Change Canada issues the weather alerts for North Riverdale; 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 Riverdale, 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 Riverdale
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| North Riverdale | Low | $0.043 | 2.7% | Yes |
| Playter Estates-Danforth 7,712 · 0.9 km | Low | $0.043 | 2.7% | Yes |
| Blake-Jones 7,494 · 0.9 km | Low | $0.043 | 2.7% | None listed |
| South Riverdale 28,264 · 1.1 km | Low | $0.043 | 2.7% | Yes |
| Regent Park 12,797 · 1.6 km | Low | $0.043 | 2.7% | Yes |
| Broadview North 11,080 · 1.8 km | Low | $0.043 | 2.7% | Yes |
| Cabbagetown-South St.James Town 11,205 · 1.8 km | Low | $0.043 | 2.7% | Yes |
The fire record around Broadview North is a touch heavier than North Riverdale’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 Riverdale faces
What to do about the hazards North Riverdale 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
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; North Riverdale’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 North Riverdale without grading them.
- Wildfire counts one way. Wildfire is read from the national burned-area record around North Riverdale’s 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 North Riverdale until then.
Questions about flooding and hazards in North Riverdale
Does North Riverdale flood?
A flood study covers North Riverdale 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 North Riverdale?
About $0.043 a year per $1,000 of building value, NRCan’s long-run expectation for North Riverdale.
How is North Riverdale’s Hazard risk Grade worked out?
North Riverdale grades A− for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is radon a problem in North Riverdale?
In Health Canada’s survey, 2.7% of 74 homes tested in North Riverdale’s area were above 200 Bq/m³, though only a test tells you about one house.
Is North Riverdale at risk of wildfire?
The burned-area record shows next to nothing around North Riverdale (0% within 25 km since 1986), so its band is low.
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).