Photo: Balcer~commonswiki · CC BY 2.5A flood study covers Caledonia: 6 on the national inventory, the newest from Niagara Peninsula Conservation Authority
Around Caledonia, wildfire is practically absent from the record: 0% within 25 km since 1986, 0.000% a year. Seismic risk in Caledonia sits near the middle: $0.040 of expected damage per $1,000 of buildings a year, the typical town $0.030. In Health Canada’s survey, just 2.6% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Hazard risk gives Caledonia a grade of A−, from earthquakes and radon alone.
What stands out about Caledonia’s hazards
Four national sources, each read for Caledonia: earthquakes, radon, past fires and flood studies.
What Caledonia faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Caledonia grades A− for hazard risk
The grade weighs Caledonia’s seismic risk and radon equally, and wildfire is one-sided: a high band counts against a town, a low one earns nothing.
Its place: #283 of 866 in Ontario and #681 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Small fires and grass fires are largely missing from the national burned-area record.
Few fires near Caledonia: 0% within 5 km, 0% within 25 km
Past fire around Caledonia’s homes, from the national burned-area record, with the fuel within 5 km.
Caledonia burns at 0.000% a year, low against 0.000% for the typical Canadian town.
Only 0.7% of the land within 25 km of Caledonia is forest fuel, and 0.7% close in.
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
Of the 871 towns in Ontario, 638 have a burn rate that rounds to zero, Caledonia 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.
Measured against 2,610 towns, Caledonia is in the largest group, low (92%), and at its floor, while 7.5% rank higher.
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.
Caledonia is on the flood map inventory: 6 studies, latest by Niagara Peninsula Conservation Authority
What Canada’s Flood Map Inventory lists for Caledonia: who studied flooding and where to see their maps.
6 studies on the inventory touch Caledonia, the newest Niagara Peninsula Conservation Authority’s from 2025, and their areas can be large, so they say maps exist, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| Oswego Creek | Niagara Peninsula Conservation Authority | 2025 | under review |
| Welland River | Niagara Peninsula Conservation Authority | 2018 | final |
| Grand River Regulatory Floodplain | Grand River Conservation Authority | 2018 | final |
| BuckhornCreek | Niagara Peninsula Conservation Authority | final | |
| OswegoCreek | Niagara Peninsula Conservation Authority | final | |
| OswegoCreektrib | Niagara Peninsula Conservation Authority | final |
Towns with a flood study on file
Its flood study puts Caledonia with 69% of towns in Ontario; Canada’s share is 58%.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
The busiest decade for flood studies around Caledonia was the 2010s (2 of 3); they run from the 2010s to the 2020s.
Study dates as the NRCan inventory lists them, one count per study touching Caledonia.
Flood mapping is shown for Caledonia 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.”
Natural Resources Canada, Canada Flood Map Inventory; links go to each study’s owner.
Earthquakes cost buildings in Caledonia $0.040 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
With $0.040 of shaking damage a year per $1,000, Caledonia is about even with the typical $0.030 (1.3 times).
Shaking damage a year per $1,000 of building value
Typical for its province: Caledonia at $0.040 beside a median in Ontario of $0.043, with Alexandria on top 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.
Around half of Canada’s 2,611 towns expect more shaking damage than Caledonia (43%).
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 Caledonia’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).
2.6% of homes tested around Caledonia are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
Caledonia’s survey area reads 2.6% over the guideline, under the typical Canadian town’s 6.6%. Nobody publishes radon tests for Caledonia alone, so this card uses the figure for the Haldimand-Norfolk Health Unit.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Fewer homes top the guideline around Caledonia (2.6%) 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.
Radon rarely tops the guideline around Caledonia, as for 37% of Canada’s 2,611 towns; 63% see more.
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 Caledonia 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 Caledonia
Alerts for Caledonia 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. |
Fire danger and active fires near Caledonia are mapped daily by the Canadian Wildland Fire Information System; evacuation orders come from the municipality or province.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Caledonia
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Caledonia | Low | $0.040 | 2.6% | Yes |
| Six Nations (Part) 40 1,162 · 16 km | Low | $0.028 | 10% | Yes |
Among its neighbours Caledonia has the most fire on record (low); Six Nations (Part) 40 follows (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Caledonia faces
What to do about the hazards Caledonia 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. Shaking damage is modelled from the ground, the buildings and the odds of each quake, and published for whole subdivisions such as Caledonia’s.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Caledonia 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 Caledonia.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Caledonia’s 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 Caledonia
How big is the earthquake risk in Caledonia?
NRCan’s model expects shaking to cost buildings in Caledonia $0.040 a year for every $1,000 of their value, on average over many years.
Is Caledonia at risk of wildfire?
The burned-area record shows next to nothing around Caledonia (0% within 25 km since 1986), so its band is low.
Does Caledonia flood?
The inventory lists a study touching Caledonia; whether a given street floods is on that map, not in the grade.
How is Caledonia’s Hazard risk Grade worked out?
Hazard risk gives Caledonia A−, weighing earthquakes and radon and counting wildfire only against it.
Is radon a problem in Caledonia?
In Health Canada’s survey, 2.6% of 116 homes tested in Caledonia’s area were above 200 Bq/m³, though only a test tells you about one house.
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).