Photo: Drozwik Drones · CC BY 3.0Cobourg is on Canada’s flood inventory: 3 listed, led by Ganaraska Region Conservation Authority
The national fire record shows next to nothing around Cobourg, 0% of the land within 25 km since 1986 (0.000% a year). For earthquakes Cobourg is middling, $0.034 a year per $1,000 against $0.030 for the typical town. Radon is about average around Cobourg: 6.1% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Cobourg grades B+ for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Cobourg’s hazards
Four national sources, each read for Cobourg: earthquakes, radon, past fires and flood studies.
What Cobourg faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Cobourg grades B+ for hazard risk
For Cobourg, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #485 of 866 in Ontario and #1,068 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.
Little of the land around Cobourg has burned: 0% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where Cobourg’s residents live, and the fuel next to their homes.
In a typical year 0.000% of the land near Cobourg burns; the typical Canadian town sees 0.000%, and both are low.
Forest fuel is spread evenly around Cobourg: 13% within 5 km, 16% 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
Near-zero burning puts Cobourg with 638 of the 871 towns in Ontario, far below Sioux Lookout 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.
Like most of Canada’s 2,610 towns (92%), Cobourg 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.
Flooding around Cobourg is mapped in 3 studies, the newest by Ganaraska Region Conservation Authority
Flood studies whose area touches Cobourg, from NRCan’s inventory, each linked to its owner.
Ganaraska Region Conservation Authority and others have studied flooding in areas that include Cobourg: 3 studies, the latest from 2008.
| Study | By | Year | Status |
|---|---|---|---|
| Brook Creek Town of Cobourg Floodline Mapping Study TSH | Ganaraska Region Conservation Authority | 2008 | final · not public |
| Cobourg Creek Town of Cobourg Floodline Mapping Study TSH | Ganaraska Region Conservation Authority | 2008 | final · not public |
| Massey Creek Town of Cobourg Floodline Mapping Study TSH | Ganaraska Region Conservation Authority | 2008 | final · not public |
Towns with a flood study on file
Mapping in Ontario reaches 69% of towns, Cobourg included, beside 58% across Canada.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood is shown here, never graded: a study says where a map exists, not how many of Cobourg’s homes stand in a flood zone.
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 Cobourg: $0.034 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.
At $0.034 per $1,000, Cobourg’s earthquake risk is about the typical Canadian town’s ($0.030; 1.1 times).
Shaking damage a year per $1,000 of building value
At $0.034, Cobourg is below the typical town in Ontario ($0.043); Alexandria is highest 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.
Cobourg’s earthquake risk lands near the centre of Canada’s range; 46% 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).
Roads, pipes and bridges aren’t in Cobourg’s figure, nor landslides or tsunami: it is buildings and shaking.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Radon about average around Cobourg: 6.1% over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
Cobourg’s area, at 6.1%, is close to the 6.6% of the typical Canadian town. Cobourg shares its radon tests numbers with the rest of the Haliburton, Kawartha, Pine Ridge District Heal health region.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Cobourg, 6.1% of tests were over 200 Bq/m³ and 1% 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.
Radon tops the guideline in a modest share of homes around Cobourg, a band holding 37% of Canada’s 2,611 towns; 26% rank above.
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 Cobourg as anywhere, test to be sure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Cobourg
Environment and Climate Change Canada issues the weather alerts for Cobourg; 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 Cobourg, 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)
How Cobourg’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Cobourg | Low | $0.034 | 6.1% | Yes |
| Hamilton 11,810 · 9.5 km | Low | $0.026 | 6.1% | Yes |
| Port Hope 18,446 · 11 km | Low | $0.030 | 6.1% | Yes |
| Alnwick/Haldimand 8,197 · 15 km | Low | $0.026 | 6.1% | Yes |
Nowhere around Cobourg burns more: Hamilton, the closest rival, is low to its low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Cobourg faces
Practical steps for Cobourg’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
- Wildfire counts one way. Wildfire is read from the national burned-area record around Cobourg’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Cobourg’s figure is its subdivision’s.
- Flood studies aren’t flood zones. NRCan’s inventory says where flood mapping exists, not where water goes; the map’s owner is the authority for Cobourg.
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Cobourg is its health region’s, the survey’s design unit.
Questions about flooding and hazards in Cobourg
Does Cobourg flood?
There is flood mapping for Cobourg on the national inventory, each study linked to its owner’s map, none of them graded.
How is Cobourg’s Hazard risk Grade worked out?
Hazard risk gives Cobourg B+, weighing earthquakes and radon and counting wildfire only against it.
Is radon a problem in Cobourg?
The area’s survey found 6.1% of 98 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Cobourg.
Is Cobourg at risk of wildfire?
Very little by the national record: Cobourg’s band is low, with 0% of the land within 25 km burned since 1986, so wildfire doesn’t change its grade.
How big is the earthquake risk in Cobourg?
Expected earthquake damage in Cobourg comes to $0.034 a year for each $1,000 that buildings are worth.
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).