Photo: GTD Aquitaine · Public domainPeterborough is on Canada’s flood inventory: 2 listed, led by Otonabee Region Conservation Authority
No wildfire is mapped within 25 km of Peterborough’s homes since 1986 (0% of the land, 0.000% a year). For earthquakes Peterborough is middling, $0.025 a year per $1,000 against $0.030 for the typical town. Radon is about average around Peterborough: 8.9% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Hazard risk gives Peterborough a grade of B, from earthquakes and radon alone.
What stands out about Peterborough’s hazards
Four national sources, each read for Peterborough: earthquakes, radon, past fires and flood studies.
What Peterborough faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Peterborough grades B for hazard risk
Earthquake risk and radon make Peterborough’s grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
Its place: #639 of 866 in Ontario and #1,515 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.
Little of the land around Peterborough has burned: 0% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where Peterborough’s residents live, and the fuel next to their homes.
The land within 25 km of Peterborough burns at 0.000% a year on average, the low band; the typical Canadian town: 0.000%.
Forest fuel covers 6.4% of the land close to Peterborough and 14% across 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 Peterborough 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; Peterborough 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.
2 flood studies cover Peterborough, the newest from Otonabee Region Conservation Authority
Flood studies whose area touches Peterborough, from NRCan’s inventory, each linked to its owner.
Otonabee Region Conservation Authority and others have studied flooding in areas that include Peterborough: 2 studies, the latest from 2025.
| Study | By | Year | Status |
|---|---|---|---|
| Byersville Creek Floodplain Mapping Study | Otonabee Region Conservation Authority | 2025 | final |
| Peterborough | Ontonabee Region Conservation Authority | 1991 | final · not public |
Towns with a flood study on file
Mapping in Ontario reaches 69% of towns, Peterborough 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.
The 2 studies touching Peterborough are spread over time, from the 1990s to the 2020s.
Study dates as the NRCan inventory lists them, one count per study touching Peterborough.
Flood is shown here, never graded: a study says where a map exists, not how many of Peterborough’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.
Earthquakes cost buildings in Peterborough $0.025 per $1,000 a year
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
Nothing unusual about Peterborough’s ground: $0.025 against a typical $0.030, 0.8 times.
Shaking damage a year per $1,000 of building value
Peterborough’s $0.025 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.
Middle of the pack: 53% of Canada’s 2,611 towns have more earthquake risk than Peterborough.
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 Peterborough’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).
Radon about average around Peterborough: 8.9% over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
The survey area of Peterborough reads 8.9%, a shade from the typical Canadian town’s 6.6%. Behind radon tests sits data gathered across the Peterborough County-City Health Unit, with Peterborough one part of it.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Peterborough, 8.9% of tests were over 200 Bq/m³ and 0.9% 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.
Between 5% and 10% of tests over the guideline: Peterborough, and 37% of Canada’s 2,611 towns; 26% 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.
The survey sampled homes around Peterborough; it can’t tell you your basement’s level.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Peterborough
Environment and Climate Change Canada issues the weather alerts for Peterborough; 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. |
In fire season, check CWFIS for danger and active fires around Peterborough, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Peterborough
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Peterborough | Low | $0.025 | 8.9% | Yes |
| Otonabee-South Monaghan 8,084 · 11 km | Low | $0.029 | 8.9% | Yes |
| Bridgenorth 20,628 · 12 km | Low | $0.026 | 8.9% | Yes |
| Millbrook 11,507 · 16 km | Low | $0.023 | 8.9% | Yes |
| Douro-Dummer 8,379 · 18 km | Low | $0.030 | 8.9% | Yes |
The neighbour with the most fire is Otonabee-South Monaghan (low), still no more than Peterborough (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Peterborough faces
Practical steps for Peterborough’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 Peterborough sits in.
- 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 Peterborough’s.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Peterborough’s homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- 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 Peterborough floods.
Questions about flooding and hazards in Peterborough
How is Peterborough’s Hazard risk Grade worked out?
Peterborough grades B for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is Peterborough at risk of wildfire?
Very little by the national record: Peterborough’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 Peterborough?
Expected earthquake damage in Peterborough comes to $0.025 a year for each $1,000 that buildings are worth.
Does Peterborough flood?
Peterborough’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 Peterborough?
8.9% of the 112 homes Health Canada tested around Peterborough topped the guideline; your own house needs its own test.
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).