Photo: South Algonquin Business Alliance · CC BY-SA 4.0Wildfire low, radon 8%: how South Algonquin stands on hazards
Burn scars are few around South Algonquin, with 0.1% of the land within 25 km touched by fire since 1986 (0.001% a year). Earthquake risk in South Algonquin is ordinary: NRCan’s model puts building losses at $0.030 a year per $1,000 of value, close to the typical town’s $0.030. South Algonquin grades B+ for hazard risk, with wildfire counted against it.
What stands out about South Algonquin’s hazards
For South Algonquin, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What South Algonquin faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
South Algonquin grades B+ for hazard risk
Two inputs always count for South Algonquin, earthquakes and radon; the third, wildfire, counts only against a town.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Few fires near South Algonquin: 0% within 5 km, 0.1% within 25 km
Past fire around South Algonquin’s homes, from the national burned-area record, with the fuel within 5 km.
At 0.001% of the land a year, South Algonquin’s burn rate is in the low band; the typical Canadian town sees 0.000%.
Since 1986 the nearest fire to South Algonquin’s homes came within 16 km, never inside 5 km.
About as much forest grows next to South Algonquin’s homes (37% within 5 km) as across 25 km (32%).
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 872
South Algonquin ranks 83rd of the 872 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.
Low, like 92% of the country’s 2,610 towns: the land around South Algonquin burns, but slower than in the 7.5% above it.
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 South Algonquin
What Canada’s Flood Map Inventory lists for South Algonquin: who studied flooding and where to see their maps.
NRCan’s inventory is silent on South Algonquin, so any flood map would be the municipality’s own.
Towns with a flood study on file
69% of towns in Ontario have a flood study, more than Canada’s 58%; South Algonquin is not yet one of them.
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 South Algonquin’s 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 South Algonquin $0.030 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
South Algonquin’s $0.030 matches the typical town’s $0.030.
Shaking damage a year per $1,000 of building value
Earthquake risk in Ontario peaks in Alexandria ($0.21); South Algonquin, at $0.030, is below the median of $0.043.
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: 48% of Canada’s 2,611 towns have more earthquake risk than South Algonquin.
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 South Algonquin 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).
Some radon around South Algonquin: 8% of area homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
8% of tested homes around South Algonquin were over the guideline, much like the typical Canadian town at 6.6%. South Algonquin doesn’t get its own radon tests figures; the ones here come from the Renfrew County and District Health Unit.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around South Algonquin than in most towns in Ontario: 8% over the guideline (4% is typical), 1% over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
A middling share of high tests puts South Algonquin with 37% of Canada’s 2,611 towns, below 26% of them.
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.
Radon varies from house to house in South Algonquin, so the survey is a reason to test, not a result for yours.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in South Algonquin
Environment and Climate Change Canada issues the weather alerts for South Algonquin; 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 South Algonquin, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Get ready for what South Algonquin faces
What to do about the hazards South Algonquin 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
- Flood studies aren’t flood zones. The flood inventory points to maps; it is incomplete and not the official source, so ask the municipality about any street in South Algonquin.
- 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 South Algonquin.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, South Algonquin’s included.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, South Algonquin takes its 2007 health region’s share.
Questions about flooding and hazards in South Algonquin
Is radon a problem in South Algonquin?
Around South Algonquin, 100 survey homes were tested and 8% came in over 200 Bq/m³, a guide to the area, not to any one home.
Is South Algonquin at risk of wildfire?
Fire has reached 0.1% of the land around South Algonquin since 1986 (last in 2002); at low, it neither helps nor hurts the grade.
Does South Algonquin flood?
With 0 studies on the inventory, South Algonquin’s flood risk is unmapped nationally; check with the municipality before buying.
How is South Algonquin’s Hazard risk Grade worked out?
South Algonquin’s Hazard risk grade is B+, built on earthquakes and radon with a one-sided wildfire input.
How big is the earthquake risk in South Algonquin?
In NRCan’s seismic model, South Algonquin’s buildings lose $0.030 per $1,000 of value in an average year.
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).