Photo: maar345 · CC BY 2.0Wildfire low, radon 8%: how Renfrew stands on hazards
No wildfire is mapped within 25 km of Renfrew’s homes since 1986 (0% of the land, 0.000% a year). Earthquakes add more: NRCan’s model puts building losses at $0.10 a year per $1,000 of value, against $0.030 for the typical town. Renfrew grades C+ for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Renfrew’s hazards
For Renfrew, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Renfrew faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Renfrew: C+
Earthquake risk and radon make Renfrew’s grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
Its place: #701 of 866 in Ontario and #1,890 of 2,589 Canadian towns.
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.
Wildfire is rare near Renfrew: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Renfrew’s residents live, and the fuel next to their homes.
Low: the land around Renfrew burns at 0.000% a year, where the typical Canadian town sees 0.000%.
Forest fuel covers 19% of the land close to Renfrew and 32% across 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
Fire has taken almost none of the land around Renfrew, as for 638 of the 871 towns in Ontario; Sioux Lookout tops the list 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.
92% of Canada’s 2,610 towns are in the low band and 7.5% above it; Renfrew is among the many where the yearly burn rate 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.
No flood study is listed for Renfrew
Flood studies whose area touches Renfrew, from NRCan’s inventory, each linked to its owner.
NRCan’s inventory is silent on Renfrew, so any flood map would be the municipality’s own.
Towns with a flood study on file
Mapping in Ontario reaches 69% of towns, beside 58% across Canada, but not Renfrew.
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 Renfrew’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.”
Earthquakes cost buildings in Renfrew $0.10 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.
Roughly 3.4 times the typical $0.030: Renfrew’s $0.10 marks real seismic exposure.
Shaking damage a year per $1,000 of building value
The typical town in Ontario expects $0.043 a year; Renfrew expects $0.10, and Alexandria $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.
More earthquake risk than most: only 26% of Canada’s 2,611 towns are above Renfrew.
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).
What a quake does after the shaking, fire, landslides, tsunami, falls outside NRCan’s figure for Renfrew.
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 Renfrew: 8% of area homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · The radon tests numbers here cover the Renfrew County and District Health Unit
Around Renfrew, 8% of tested homes topped the guideline, near the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Renfrew, 8% of tests were over 200 Bq/m³ and 1% over 600, against a median of 4% in Ontario.
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 Renfrew’s 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.
Whatever Renfrew’s area share, the reading that matters is your own home’s, over a winter.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Renfrew
Environment and Climate Change Canada issues the weather alerts for Renfrew; 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 Renfrew, 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 Renfrew’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Renfrew | Low | $0.10 | 8% | None listed |
| Horton 3,550 · 8.3 km | Low | $0.098 | 8% | Yes |
| Admaston/Bromley 3,086 · 12 km | Low | $0.10 | 8% | None listed |
Admaston/Bromley burns a little more than Renfrew, in the same low band (low here).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Renfrew faces
Practical steps for Renfrew’s 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
- Wildfire counts one way. For Renfrew, 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 Renfrew is its health region’s, the survey’s design unit.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Renfrew’s census subdivision (a neighbourhood shows its city’s).
- 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 Renfrew.
Questions about flooding and hazards in Renfrew
Does Renfrew flood?
The inventory has 0 studies for Renfrew, and an empty list isn’t a clean bill: the municipality holds any flood maps.
Is Renfrew at risk of wildfire?
No meaningful wildfire history near Renfrew: 0% of nearby land since 1986, band low.
Is radon a problem in Renfrew?
The area’s survey found 8% of 100 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Renfrew.
How is Renfrew’s Hazard risk Grade worked out?
Renfrew grades C+ for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
How big is the earthquake risk in Renfrew?
About $0.10 a year per $1,000 of building value, NRCan’s long-run expectation for Renfrew.
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).