Photo: Tabercil · CC BY 3.0Durham is on Canada’s flood inventory: 1 listed, led by Saugeen Valley Conservation Authority
Fire has left almost no mark near Durham: 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. In Health Canada’s survey, 11% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Durham grades B for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Durham’s hazards
For Durham, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Durham faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Durham grades B for hazard risk
Seismic risk and radon set Durham’s grade, wildfire can drag it down, and flood mapping stays out of 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. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Wildfire is rare near Durham: 0% of the land within 25 km burned since 1986, 0% within 5 km
Past fire around Durham’s homes, from the national burned-area record, with the fuel within 5 km.
The yearly burn rate around Durham is 0.000%, low beside 0.000% for the typical Canadian town.
More forest grows near Durham’s homes (22% within 5 km) than across 25 km (13%).
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
Sioux Lookout has the highest burn rate in Ontario, 0.16% a year; around Durham, as around 638 of the 871 towns, it rounds to zero.
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%), Durham 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 Durham, from Saugeen Valley Conservation Authority: 1 on the inventory
What Canada’s Flood Map Inventory lists for Durham: who studied flooding and where to see their maps.
Saugeen Valley Conservation Authority studied flooding in an area that includes Durham (2024); open its map to see which streets lie in a flood zone.
| Study | By | Year | Status |
|---|---|---|---|
| Durham Creek Flood Hazard Mapping | Saugeen Valley Conservation Authority | 2024 | final |
Towns with a flood study on file
Its flood study puts Durham 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.
Flood studies don’t enter the grade; they are listed so you can open the official map for Durham.
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.
Little shaking expected in Durham: $0.013 a year per $1,000
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
At $0.013 per $1,000, Durham carries 0.4 times the typical Canadian town’s earthquake risk ($0.030): low.
Shaking damage a year per $1,000 of building value
Below the middle in Ontario: Durham’s $0.013 against a median of $0.043; Alexandria has $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 Durham.
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).
Only shaking damage to buildings in Durham is counted; landslides, liquefaction, tsunami and fire after a quake aren’t.
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 Durham: 11% of area homes were over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
Durham’s area, at 11%, is above the 6.6% of the typical Canadian town, so testing is worth more here than most places. Behind radon tests sits data gathered across the Grey Bruce Health Unit, with Durham one part of it.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Durham’s area, at 11%, is above the median in Ontario (4%), and 1% of its tests passed 600 Bq/m³.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Durham is in the 10–20% band, with 22% of Canada’s 2,611 towns; only 4.6% are 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 low area share in Durham doesn’t clear a house, nor does a high one condemn it: test.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Durham
Alerts for Durham 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. |
Alert Ready carries evacuation orders for Durham to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Durham’s neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Durham | Low | $0.013 | 11% | Yes |
| Hanover 8,723 · 15 km | Low | $0.013 | 11% | None listed |
Durham’s low band tops its neighbours; Hanover is next (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Durham faces
Practical steps for Durham’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
- 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 Durham sits in.
- Wildfire counts one way. Burned land within 25 km of where people live, averaged over 1986–2025 and checked for fuel near homes, is the measure; it looks back, not ahead, and only ever counts against Durham.
- 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 Durham floods.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Durham’s included.
Questions about flooding and hazards in Durham
How is Durham’s Hazard risk Grade worked out?
Hazard risk gives Durham B, weighing earthquakes and radon and counting wildfire only against it.
Is Durham at risk of wildfire?
No meaningful wildfire history near Durham: 0% of nearby land since 1986, band low.
Is radon a problem in Durham?
11% of the 98 homes Health Canada tested around Durham topped the guideline; your own house needs its own test.
How big is the earthquake risk in Durham?
In NRCan’s seismic model, Durham’s buildings lose $0.013 per $1,000 of value in an average year.
Does Durham flood?
Durham’s area has been studied for flooding, and the owner’s map shows which streets lie in a zone; the grade leaves flood out.
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).