Photo: Chicken4War · CC BY-SA 4.0Hazards in Roncesvalles are mild: low wildfire and earthquake risk, and 2.7% of area homes above the radon guideline
The burned-area map is nearly blank around Roncesvalles, 0% within 25 km since 1986, 0.000% a year. NRCan expects $0.043 of shaking damage a year per $1,000 of buildings in Roncesvalles, near the typical $0.030. Roncesvalles grades A− for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Roncesvalles’s hazards
For Roncesvalles, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Roncesvalles faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Roncesvalles grades A− for hazard risk
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Roncesvalles 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: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Only 74 homes were tested in the survey area, so the radon share is rough. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Little of the land around Roncesvalles has burned: 0% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where Roncesvalles’ residents live, and the fuel next to their homes.
Low by Canadian standards: 0.000% of the land a year around Roncesvalles, 0.000% for the typical Canadian town.
Forest makes up 0.6% of the land within 5 km of Roncesvalles and 0.5% 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
To three decimals the burn rate around Roncesvalles is zero, as for 638 of the 871 towns in Ontario, while Sioux Lookout reaches 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.
Roncesvalles shares the low band with 92% of Canada’s 2,610 towns, its burn rate rounding to nothing; 7.5% burn faster.
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.
No flood study is listed for Roncesvalles
Flood studies whose area touches Roncesvalles, from NRCan’s inventory, each linked to its owner.
Canada’s Flood Map Inventory lists no study whose area touches Roncesvalles, which doesn’t mean it has never been mapped.
Towns with a flood study on file
Missing from a well-mapped province: Roncesvalles has no study, where 69% of towns in Ontario have one against 58% nationally.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood is shown here, never graded: a study says where a map exists, not how many of Roncesvalles’ homes stand in a flood zone.
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.”
Earthquakes cost buildings in Roncesvalles $0.043 per $1,000 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 Roncesvalles, $0.043 per $1,000, are in line with the typical $0.030 (1.4 times).
Shaking damage a year per $1,000 of building value
The median in Ontario is $0.043; Roncesvalles, at $0.043, is right beside it, and Alexandria tops the list 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.
Around half of Canada’s 2,611 towns expect more shaking damage than Roncesvalles (36%).
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).
For Roncesvalles the model prices shaking damage to buildings, nothing more.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean). · Earthquake risk: one figure for all of the city of Toronto
Radon runs low around Roncesvalles: 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. · Measured across the City of Toronto Health Unit: radon tests
Fewer homes than usual test high around Roncesvalles: 2.7% against 6.6% for the typical Canadian town.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
The median in Ontario is 4% over 200 Bq/m³; around Roncesvalles it is 2.7%.
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 Roncesvalles; 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.
Health Canada advises testing every home, Roncesvalles’ included, whatever the area’s figure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Roncesvalles
Environment and Climate Change Canada issues the weather alerts for Roncesvalles; 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 Roncesvalles, 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 Roncesvalles’ neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Roncesvalles | Low | $0.043 | 2.7% | None listed |
| Little Portugal 15,669 · 1.2 km | Low | $0.043 | 2.7% | None listed |
| Dufferin Grove 11,276 · 1.2 km | Low | $0.043 | 2.7% | None listed |
| South Parkdale 21,663 · 1.3 km | Low | $0.043 | 2.7% | Yes |
| Junction-Wallace Emerson 23,484 · 2.0 km | Low | $0.043 | 2.7% | None listed |
| Trinity-Bellwoods 15,691 · 2.1 km | Low | $0.043 | 2.7% | None listed |
| High Park North 22,162 · 2.1 km | Low | $0.043 | 2.7% | None listed |
Little Portugal (low) has the heaviest fire record of Roncesvalles’ neighbours, and Roncesvalles (low) matches or beats it.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Roncesvalles faces
What to do about the hazards Roncesvalles 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?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
What this data can and can’t tell you
- Wildfire counts one way. For Roncesvalles, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Roncesvalles is its health region’s, the survey’s design unit.
- Flood studies aren’t flood zones. NRCan’s inventory says where flood mapping exists, not where water goes; the map’s owner is the authority for Roncesvalles.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Roncesvalles’ census subdivision (a neighbourhood shows its city’s).
Questions about flooding and hazards in Roncesvalles
How big is the earthquake risk in Roncesvalles?
Expected earthquake damage in Roncesvalles comes to $0.043 a year for each $1,000 that buildings are worth.
How is Roncesvalles’s Hazard risk Grade worked out?
Roncesvalles’ Hazard risk grade is A−, built on earthquakes and radon with a one-sided wildfire input.
Is Roncesvalles at risk of wildfire?
Hardly at all on record: 0% of the land within 25 km of Roncesvalles since 1986, a low band, though small grass fires aren’t mapped.
Does Roncesvalles flood?
With 0 studies on the inventory, Roncesvalles’ flood risk is unmapped nationally; check with the municipality before buying.
Is radon a problem in Roncesvalles?
Around Roncesvalles, 74 survey homes were tested and 2.7% came in over 200 Bq/m³, a guide to the area, not to any one home.
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).