Photo: Municipal Affairs and Housing · CC BY 2.0Few places are as safe from hazards as Orillia: it beats 94% of Canadian towns
Little of the land around Orillia has burned: 0.1% within 25 km since 1986, or 0.002% a year. Shaking is about as much of a worry in Orillia as in most places, at $0.019 a year per $1,000 of building value ($0.030 typical). In Health Canada’s survey, just 0.9% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Orillia grades A for hazard risk, with wildfire counted against it.
What stands out about Orillia’s hazards
For Orillia, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Orillia faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Orillia grades A for hazard risk
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Orillia with little fire nearby would get no credit for it.
Its place: #21 of 866 in Ontario and #263 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.
Little of the land around Orillia has burned: 0% within 5 km, 0.1% within 25 km since 1986
Fires mapped since 1986 around where Orillia’s residents live, and the fuel next to their homes.
Fire claims 0.002% of the land around Orillia each year, a low band, with the typical Canadian town at 0.000%.
Since 1986 the nearest fire to Orillia’s homes came within 18 km, never inside 5 km.
14% of the land within 5 km of Orillia is forest fuel, close to the 18% 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
Orillia ranks 54th of the 871 towns in Ontario for burn rate, at 0.002% a year; Sioux Lookout leads with 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.
7.5% of Canada’s 2,610 towns burn fast enough to rank moderate or above; Orillia stays low, with 92%.
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 Orillia, from City of Orillia: 1 on the inventory
Flood studies whose area touches Orillia, from NRCan’s inventory, each linked to its owner.
City of Orillia studied flooding in an area that includes Orillia (2025); open its map to see which streets lie in a flood zone.
| Study | By | Year | Status |
|---|---|---|---|
| Mill Creek and Ben's Ditch Flood Plain Mapping - Two Dimensional (2D) Hydraulic Modelling | City of Orillia | 2025 | final |
Towns with a flood study on file
Its flood study puts Orillia 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 mapping is shown for Orillia 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.
Expected shaking damage in Orillia: $0.019 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.
Earthquake losses in Orillia, $0.019 per $1,000, are in line with the typical $0.030 (0.6 times).
Shaking damage a year per $1,000 of building value
At $0.019, Orillia 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.
Earthquakes cost less around Orillia than in 66% 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).
For Orillia the model prices shaking damage to buildings, nothing more.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Radon runs low around Orillia: 0.9% of tested homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Radon tests for the Simcoe Muskoka District Health Unit
Where the typical Canadian town has 6.6% of homes over the guideline, Orillia’s area has fewer, 0.9%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Orillia’s area, at 0.9%, is below the median 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 Orillia, 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 low area share in Orillia 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 Orillia
Alerts for Orillia 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 Orillia 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)
Hazards in the places around Orillia
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Orillia | Low | $0.019 | 0.9% | Yes |
| Severn 15,716 · 7.1 km | Low | $0.019 | 0.9% | Yes |
| Chippewas of Rama First Nation 1,149 · 8.3 km | Low | $0.028 | 0.9% | Yes |
| Oro-Medonte 24,681 · 14 km | Low | $0.015 | 0.9% | Yes |
| Ramara 11,551 · 16 km | Low | $0.026 | 0.9% | Yes |
Fire is no heavier anywhere nearby than around Orillia (low), with Chippewas of Rama First Nation next at low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Orillia faces
What to do about the hazards Orillia 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. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Orillia’s included.
- 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 Orillia.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Orillia without grading them.
- 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 Orillia until then.
Questions about flooding and hazards in Orillia
Does Orillia flood?
A flood study covers Orillia on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
How is Orillia’s Hazard risk Grade worked out?
Orillia grades A for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is radon a problem in Orillia?
In Health Canada’s survey, 0.9% of 109 homes tested in Orillia’s area were above 200 Bq/m³, though only a test tells you about one house.
How big is the earthquake risk in Orillia?
Expected earthquake damage in Orillia comes to $0.019 a year for each $1,000 that buildings are worth.
Is Orillia at risk of wildfire?
Less than most of Canada: 0.1% of the land within 25 km of Orillia has burned since 1986, the last in 2018, a low band that leaves Risk alone.
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).