Photo: P199 · CC BY-SA 3.0Wildfire low, radon 11%: how Chatsworth stands on hazards
Wildfire barely registers for Chatsworth, at 0% of the land within 25 km since 1986 (0.000% a year). Seismic risk runs low: $0.013 of expected damage per $1,000 of buildings a year, the typical town $0.030. Chatsworth grades B for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Chatsworth’s hazards
Four national sources, each read for Chatsworth: earthquakes, radon, past fires and flood studies.
What Chatsworth faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Chatsworth: B
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Chatsworth with little fire nearby would get no credit for it.
Its place: #619 of 866 in Ontario and #1,421 of 2,589 Canadian towns.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. Small fires and grass fires are largely missing from the national burned-area record.
Wildfire is rare near Chatsworth: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Chatsworth’s residents live, and the fuel next to their homes.
The yearly burn rate around Chatsworth is 0.000%, low beside 0.000% for the typical Canadian town.
More forest grows near Chatsworth’s homes (23% within 5 km) than across 25 km (16%).
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 Chatsworth 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.
92% of Canada’s 2,610 towns are in the low band and 7.5% above it; Chatsworth 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.
The flood map inventory lists nothing for Chatsworth
Flood studies whose area touches Chatsworth, from NRCan’s inventory, each linked to its owner.
No flood study on the national inventory covers Chatsworth; 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%; Chatsworth 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.
The grade leaves flood out, since a study area says nothing about how many of Chatsworth’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.”
Little shaking expected in Chatsworth: $0.013 a year per $1,000
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
0.4 times the typical $0.030: Chatsworth’s $0.013 is low for Canada.
Shaking damage a year per $1,000 of building value
Chatsworth’s $0.013 sits under the median in Ontario, $0.043, and well under Alexandria’s $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.
Most of Canada’s 2,611 towns (75%) face more earthquake damage than Chatsworth.
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).
Roads, pipes and bridges aren’t in Chatsworth’s figure, nor landslides or tsunami: it is buildings and shaking.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
11% of homes tested around Chatsworth are over the radon guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Area-wide: radon tests, counted over the Grey Bruce Health Unit
Radon runs above the typical Canadian town (6.6%) in Chatsworth’s area, at 11%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Chatsworth than in most towns in Ontario: 11% 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.
More high tests than most: Chatsworth sits in a band that only 22% of Canada’s 2,611 towns share, with 4.6% above.
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 Chatsworth 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 Chatsworth
Environment and Climate Change Canada issues the weather alerts for Chatsworth; 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 Chatsworth, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Get ready for what Chatsworth faces
What to do about the hazards Chatsworth 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
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Chatsworth’s figure is its subdivision’s.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Chatsworth’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Flood studies aren’t flood zones. A study’s area can be a whole watershed or province, so being on the inventory says a map exists, not that a home in Chatsworth floods.
- Radon is a survey. The radon share comes from about 14,000 long-term home tests in 2009–2011, pooled for now by the 2007 health region Chatsworth sits in.
Questions about flooding and hazards in Chatsworth
How big is the earthquake risk in Chatsworth?
Expected earthquake damage in Chatsworth comes to $0.013 a year for each $1,000 that buildings are worth.
Does Chatsworth flood?
With 0 studies on the inventory, Chatsworth’s flood risk is unmapped nationally; check with the municipality before buying.
Is radon a problem in Chatsworth?
Around Chatsworth, 98 survey homes were tested and 11% came in over 200 Bq/m³, a guide to the area, not to any one home.
How is Chatsworth’s Hazard risk Grade worked out?
Hazard risk gives Chatsworth B, weighing earthquakes and radon and counting wildfire only against it.
Is Chatsworth at risk of wildfire?
Very little by the national record: Chatsworth’s band is low, with 0% of the land within 25 km burned since 1986, so wildfire doesn’t change its grade.
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).