Photo: Tabercil · CC BY 3.0A flood study covers Mount Forest: 1 on the national inventory, the newest from Grand River Conservation Authority
For Mount Forest, wildfire history is close to nil: 0% of nearby land since 1986, 0.000% a year. Seismic risk in Mount Forest sits near the middle: $0.018 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%. Mount Forest grades B for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Mount Forest’s hazards
Four national sources, each read for Mount Forest: earthquakes, radon, past fires and flood studies.
What Mount Forest faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Mount Forest grades B for hazard risk
Seismic risk and radon set Mount Forest’s grade, wildfire can drag it down, and flood mapping stays out of it.
Its place: #641 of 866 in Ontario and #1,554 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 Mount Forest: 0% within 5 km, 0% within 25 km
Fires mapped since 1986 around where Mount Forest’s residents live, and the fuel next to their homes.
Low: the land around Mount Forest burns at 0.000% a year, where the typical Canadian town sees 0.000%.
Forest fuel is spread evenly around Mount Forest: 6.4% within 5 km, 8.8% 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
Of the 871 towns in Ontario, 638 have a burn rate that rounds to zero, Mount Forest 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.
Like most of Canada’s 2,610 towns (92%), Mount Forest is in the low band, with a burn rate of zero to three decimals; 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.
A flood study covers Mount Forest, from Grand River Conservation Authority: 1 on the inventory
Flood studies whose area touches Mount Forest, from NRCan’s inventory, each linked to its owner.
Grand River Conservation Authority studied flooding in an area that includes Mount Forest (2018); open its map to see which streets lie in a flood zone.
| Study | By | Year | Status |
|---|---|---|---|
| Grand River Regulatory Floodplain | Grand River Conservation Authority | 2018 | final |
Towns with a flood study on file
69% of towns in Ontario have a flood study, more than Canada’s 58%; Mount Forest has one too.
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 Mount Forest 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.
Expected shaking damage in Mount Forest: $0.018 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.
Nothing unusual about Mount Forest’s ground: $0.018 against a typical $0.030, 0.6 times.
Shaking damage a year per $1,000 of building value
Mount Forest’s $0.018 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.
Earthquakes cost less around Mount Forest than in 68% of Canada’s 2,611 towns.
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 Mount Forest’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).
11% of homes tested around Mount Forest 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 Wellington-Dufferin-Guelph Health Unit
More homes than usual test high around Mount Forest: 11% against 6.6% for the typical Canadian town.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Mount Forest, 11% of tests were over 200 Bq/m³ and 2% 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.
4.6% of Canada’s 2,611 towns have a higher share of homes over 200 Bq/m³ than Mount Forest, in the 10–20% band with 22%.
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 share describes the area, not a house: in Mount Forest as anywhere, test to be sure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Mount Forest
Alerts for Mount Forest 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 Mount Forest 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)
Get ready for what Mount Forest faces
Practical steps for Mount Forest’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?
- Check the address on the flood map.
- Are flood and wildfire insured?
What this data can and can’t tell you
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Mount Forest without grading them.
- 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 Mount Forest’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 Mount Forest until then.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Mount Forest’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 Mount Forest
How is Mount Forest’s Hazard risk Grade worked out?
Hazard risk gives Mount Forest B, weighing earthquakes and radon and counting wildfire only against it.
Does Mount Forest flood?
A flood study covers Mount Forest on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
How big is the earthquake risk in Mount Forest?
About $0.018 a year per $1,000 of building value, NRCan’s long-run expectation for Mount Forest.
Is Mount Forest at risk of wildfire?
Very little by the national record: Mount Forest’s band is low, with 0% of the land within 25 km burned since 1986, so wildfire doesn’t change its grade.
Is radon a problem in Mount Forest?
The area’s survey found 11% of 99 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Mount Forest.
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).