Photo: Balcer · CC BY 2.5Palmerston is on Canada’s flood inventory: 1 listed, led by Grand River Conservation Authority
The national fire record shows next to nothing around Palmerston, 0% of the land within 25 km since 1986 (0.000% a year). Seismic risk in Palmerston sits near the middle: $0.017 of expected damage per $1,000 of buildings a year, the typical town $0.030. More homes than usual carry radon here, 11% over the guideline where the typical town has 6.6%. Hazard risk gives Palmerston a grade of B, from earthquakes and radon alone.
What stands out about Palmerston’s hazards
Four national sources, each read for Palmerston: earthquakes, radon, past fires and flood studies.
What Palmerston faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Palmerston grades B for hazard risk
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Palmerston with little fire nearby would get no credit for it.
Its place: #635 of 866 in Ontario and #1,504 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.
Few fires near Palmerston: 0% within 5 km, 0% within 25 km
Fires mapped since 1986 around where Palmerston’s residents live, and the fuel next to their homes.
A burn rate of 0.000% a year keeps Palmerston in the low band (the typical Canadian town: 0.000%).
The forest starts beyond town: 3.4% of the land within 5 km of Palmerston’s homes is forest fuel, against 5.2% 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
Little or nothing burns around Palmerston in a typical year; 638 of the 871 towns in Ontario share that, and Sioux Lookout leads 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; Palmerston 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.
Palmerston is on the flood map inventory: 1 study, by Grand River Conservation Authority
Flood studies whose area touches Palmerston, from NRCan’s inventory, each linked to its owner.
Grand River Conservation Authority holds the flood mapping that covers Palmerston (2018), linked below.
| Study | By | Year | Status |
|---|---|---|---|
| Grand River Regulatory Floodplain | Grand River Conservation Authority | 2018 | final |
Towns with a flood study on file
Flood maps are common in Ontario: 69% of towns have one, against 58% nationally, and Palmerston is among them.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Listed, not scored: a flood study proves a map exists, not that Palmerston floods.
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.”
Natural Resources Canada, Canada Flood Map Inventory; links go to each study’s owner.
Ordinary seismic risk in Palmerston: $0.017 per $1,000 of buildings a year
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
0.6 times the typical $0.030: Palmerston’s $0.017 is ordinary.
Shaking damage a year per $1,000 of building value
The typical town in Ontario expects $0.043 a year in shaking damage; Palmerston expects less, $0.017, and Alexandria the most, $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.
Palmerston is in the lower part of Canada’s range for earthquake risk; 70% of the 2,611 towns are higher.
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 Palmerston’s 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).
Test for radon in Palmerston: 11% of area homes were over the 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 Wellington-Dufferin-Guelph Health Unit
Palmerston’s survey area reads 11% over the guideline, well past the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Palmerston than in most towns in Ontario: 11% over the guideline (4% is typical), 2% over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
One test in ten or more tops the guideline around Palmerston, as in 22% of Canada’s 2,611 towns; 4.6% go 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.
A survey sample isn’t a map: any home in Palmerston 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 Palmerston
Alerts for Palmerston 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 Palmerston 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 Palmerston’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Palmerston | Low | $0.017 | 11% | Yes |
| Howick 4,517 · 19 km | Low | $0.016 | 11% | None listed |
Howick (low) has the heaviest fire record of Palmerston’s neighbours, and Palmerston (low) matches or beats it.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Palmerston faces
What to do about the hazards Palmerston 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?
- Check the address on the flood map.
- 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; Palmerston’s figure is its subdivision’s.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Palmerston’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 Palmerston 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 Palmerston sits in.
Questions about flooding and hazards in Palmerston
How is Palmerston’s Hazard risk Grade worked out?
Palmerston’s Hazard risk grade is B, built on earthquakes and radon with a one-sided wildfire input.
How big is the earthquake risk in Palmerston?
Expected earthquake damage in Palmerston comes to $0.017 a year for each $1,000 that buildings are worth.
Does Palmerston flood?
Palmerston’s area has been studied for flooding, and the owner’s map shows which streets lie in a zone; the grade leaves flood out.
Is radon a problem in Palmerston?
Around Palmerston, 99 survey homes were tested and 11% came in over 200 Bq/m³, a guide to the area, not to any one home.
Is Palmerston at risk of wildfire?
No meaningful wildfire history near Palmerston: 0% of nearby land since 1986, band low.
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).