Photo: Phil Richards from London, UK · CC BY-SA 2.0Wildfire low, radon 6.2%: how South Keys stands on hazards
Around South Keys, wildfire is practically absent from the record: 0% within 25 km since 1986, 0.000% a year. Seismic risk runs high: $0.15 of expected damage per $1,000 of buildings a year, the typical town $0.030. Hazard risk gives South Keys a grade of C+, from earthquakes and radon alone.
What stands out about South Keys’s hazards
Four national sources, each read for South Keys: earthquakes, radon, past fires and flood studies.
What South Keys faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in South Keys: C+
Earthquake risk and radon make South Keys’ grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
Its place: #703 of 866 in Ontario and #1,894 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Only 64 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 South Keys: 0% of the land within 25 km burned since 1986, 0% within 5 km
Past fire around South Keys’ homes, from the national burned-area record, with the fuel within 5 km.
Fire claims 0.000% of the land around South Keys each year, a low band, with the typical Canadian town at 0.000%.
The 5 km ring around South Keys’ homes is clear of burns since 1986, the nearest 25 km out.
The forest starts beyond town: 1.8% of the land within 5 km of South Keys’ homes is forest fuel, against 5.9% 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
Sioux Lookout has the highest burn rate in Ontario, 0.16% a year; around South Keys, as around 638 of the 871 towns, it rounds to zero.
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.
South Keys 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 South Keys
What Canada’s Flood Map Inventory lists for South Keys: who studied flooding and where to see their maps.
No flood study on the national inventory covers South Keys; ask the municipality, which is the authority for its flood maps.
Towns with a flood study on file
69% of towns in Ontario have a flood study, more than Canada’s 58%; South Keys 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 mapping is shown for South Keys to be opened and checked, never turned into a grade.
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.”
High seismic risk in South Keys: $0.15 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Roughly 5 times the typical $0.030: South Keys’ $0.15 marks real seismic exposure.
Shaking damage a year per $1,000 of building value
Earthquake risk in Ontario peaks in Alexandria ($0.21); South Keys, at $0.15, sits above 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.
In the upper part of Canada’s range: 15% of its 2,611 towns expect more damage than South Keys.
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 South Keys’ 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). · Area behind the earthquake risk figures: the city of Ottawa
Radon about average around South Keys: 6.2% over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · Measured across the City of Ottawa Health Unit: radon tests
Around South Keys, 6.2% of tested homes topped the guideline, near the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
More homes top the guideline around South Keys (6.2%) than in the typical town in Ontario (4%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
37% of Canada’s 2,611 towns share South Keys’ band of 5 to 10%; 26% 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.
The share describes the area, not a house: in South Keys as anywhere, test to be sure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for South Keys
Alerts for South Keys come from Environment and Climate Change Canada and, for emergencies, Alert Ready.
| 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. |
Evacuation orders for South Keys come from the municipality or the province, while CWFIS maps fire danger every day.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How South Keys’ neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| South Keys | Low | $0.15 | 6.2% | None listed |
| Greenboro West 5,597 · 1.0 km | Low | $0.15 | 6.2% | None listed |
| Emerald Woods - Sawmill Creek 5,714 · 1.3 km | Low | $0.15 | 6.2% | None listed |
| Ledbury-Heron Gate-Ridgemont 15,610 · 1.7 km | Low | $0.15 | 6.2% | None listed |
| Blossom Park - Timbermill 8,907 · 1.9 km | Low | $0.15 | 6.2% | None listed |
| Greenboro East 4,800 · 2.1 km | Low | $0.15 | 6.2% | None listed |
| Riverside Park South - Revelstoke 3,030 · 2.2 km | Low | $0.15 | 6.2% | Yes |
Greenboro West (low) has the heaviest fire record of South Keys’ neighbours, and South Keys (low) matches or beats it.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what South Keys faces
Practical steps for South Keys’ hazards, most pressing first.
- 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.
- Drop, cover and hold on.
- Strap the water heater down.
- Keep 72 hours of supplies.
- Has it had a radon test?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
- Is earthquake cover included?
What this data can and can’t tell you
- Earthquakes are modelled. Shaking damage is modelled from the ground, the buildings and the odds of each quake, and published for whole subdivisions such as South Keys’.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, South Keys takes its 2007 health region’s share.
- 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 Keys.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of South Keys’ homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
Questions about flooding and hazards in South Keys
Is radon a problem in South Keys?
The area’s survey found 6.2% of 64 tested homes above Health Canada’s guideline, so a three-month test is worth doing in South Keys.
Does South Keys flood?
The inventory has 0 studies for South Keys, and an empty list isn’t a clean bill: the municipality holds any flood maps.
How big is the earthquake risk in South Keys?
NRCan’s model expects shaking to cost buildings in South Keys $0.15 a year for every $1,000 of their value, on average over many years.
How is South Keys’s Hazard risk Grade worked out?
South Keys grades C+ for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is South Keys at risk of wildfire?
Some, but South Keys’ low band (0% of nearby land burned since 1986, latest 2014) is short of the level that counts.
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).