Photo: P199 · CC BY-SA 3.0Hazards in Chisholm are mild: low wildfire and earthquake risk, and 1.9% of area homes above the radon guideline
Wildfire barely registers for Chisholm, at 0% of the land within 25 km since 1986 (0.000% a year). Seismic risk in Chisholm sits near the middle: $0.044 of expected damage per $1,000 of buildings a year, the typical town $0.030. Hazard risk gives Chisholm a grade of A−, from earthquakes and radon alone.
What stands out about Chisholm’s hazards
Four national sources, each read for Chisholm: earthquakes, radon, past fires and flood studies.
What Chisholm faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Chisholm: A−
For Chisholm, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
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 Chisholm: 0% of the land within 25 km burned since 1986, 0% within 5 km
Past fire around Chisholm’s homes, from the national burned-area record, with the fuel within 5 km.
With 0.000% burned a year, Chisholm is among the many low-band places (the typical Canadian town 0.000%).
The closest burn since 1986 lies 18 km from Chisholm’s homes, none within 5 km.
The nearer ring around Chisholm is less wooded (11% forest fuel) than the land out to 25 km (22%).
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
Of the 872 towns in Ontario, 639 have a burn rate that rounds to zero, Chisholm among them; Sioux Lookout leads at 0.16% a year.
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.
Chisholm 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.
The flood map inventory lists nothing for Chisholm
What Canada’s Flood Map Inventory lists for Chisholm: who studied flooding and where to see their maps.
Canada’s Flood Map Inventory lists no study whose area touches Chisholm, which doesn’t mean it has never been mapped.
Towns with a flood study on file
Missing from a well-mapped province: Chisholm 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.
The grade leaves flood out, since a study area says nothing about how many of Chisholm’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 Chisholm $0.044 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
With $0.044 of shaking damage a year per $1,000, Chisholm is about even with the typical $0.030 (1.5 times).
Shaking damage a year per $1,000 of building value
The median in Ontario is $0.043; Chisholm, at $0.044, 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.
32% of Canada’s 2,611 towns expect more shaking damage than Chisholm, which places it in the upper third.
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 model counts damage to Chisholm’s buildings and their occupants from shaking only: not liquefaction, landslides, tsunami or fires after a quake.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Radon runs low around Chisholm: 1.9% of tested homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
Fewer homes than usual test high around Chisholm: 1.9% against 6.6% for the typical Canadian town.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Against the typical town in Ontario (4%), the area around Chisholm has fewer high tests: 1.9%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Under 5% puts Chisholm with 37% of Canada’s 2,611 towns; 63% have more high tests.
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 survey sampled homes around Chisholm; it can’t tell you your basement’s level.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Not measured by town: radon tests (the North Bay Parry Sound District Health Unit)
Weather and fire alerts for Chisholm
Environment and Climate Change Canada issues the weather alerts for Chisholm; 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 Chisholm, 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)
Hazards in the places around Chisholm
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Chisholm | Low | $0.044 | 1.9% | None listed |
| Powassan 3,657 · 13 km | Low | $0.035 | 1.9% | None listed |
| Callander 4,021 · 16 km | Low | $0.045 | 1.9% | None listed |
| Bonfield 2,597 · 17 km | Low | $0.059 | 1.9% | None listed |
| East Ferris 5,835 · 18 km | Low | $0.056 | 1.9% | None listed |
Fire is no heavier anywhere nearby than around Chisholm (low), with Powassan next at low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Chisholm faces
Practical steps for Chisholm’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.
- 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. Wildfire is read from the national burned-area record around Chisholm’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Chisholm without grading them.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Chisholm’s figure is its subdivision’s.
- Radon is a survey. Radon figures pool the survey’s home tests by area: postal areas once their boundaries arrive, the 2007 health region around Chisholm until then.
Questions about flooding and hazards in Chisholm
Is radon a problem in Chisholm?
1.9% of the 103 homes Health Canada tested around Chisholm topped the guideline; your own house needs its own test.
Is Chisholm at risk of wildfire?
Not much by Canadian standards: Chisholm’s band is low, with 0% of the land within 25 km burned since 1986 (last in 2012), so wildfire doesn’t change its grade.
Does Chisholm flood?
No study on Canada’s Flood Map Inventory covers Chisholm (0), which doesn’t mean it has never been mapped, so ask the municipality.
How big is the earthquake risk in Chisholm?
In NRCan’s seismic model, Chisholm’s buildings lose $0.044 per $1,000 of value in an average year.
How is Chisholm’s Hazard risk Grade worked out?
Hazard risk gives Chisholm A−, weighing earthquakes and radon and counting wildfire only against it.
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).