Photo: Tyeman200 · CC BY-SA 3.0Tillsonburg’s hazards at a glance: a low wildfire record and 12% of area homes over the radon guideline
Fire has left almost no mark near Tillsonburg: 0% of the land within 25 km since 1986, 0.000% a year. For earthquakes Tillsonburg is middling, $0.022 a year per $1,000 against $0.030 for the typical town. Hazard risk gives Tillsonburg a grade of C+, from earthquakes and radon alone.
What stands out about Tillsonburg’s hazards
Four national sources, each read for Tillsonburg: earthquakes, radon, past fires and flood studies.
What Tillsonburg faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Tillsonburg: C+
Earthquake risk and radon make Tillsonburg’s grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
Its place: #666 of 866 in Ontario and #1,763 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.
Few fires near Tillsonburg: 0% within 5 km, 0% within 25 km
Past fire around Tillsonburg’s homes, from the national burned-area record, with the fuel within 5 km.
With 0.000% burned a year, Tillsonburg is among the many low-band places (the typical Canadian town 0.000%).
Land that isn’t forest covers nearly all the ground around Tillsonburg: forest fuel is 1% within 5 km and 0.7% 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 Tillsonburg 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.
Measured against 2,610 towns, Tillsonburg is in the largest group, low (92%), and at its floor, while 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.
No flood study is listed for Tillsonburg
What Canada’s Flood Map Inventory lists for Tillsonburg: who studied flooding and where to see their maps.
NRCan’s inventory is silent on Tillsonburg, so any flood map would be the municipality’s own.
Towns with a flood study on file
69% of towns in Ontario have a flood study, more than Canada’s 58%; Tillsonburg is not yet one of them.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
The grade leaves flood out, since a study area says nothing about how many of Tillsonburg’s homes are at risk.
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.”
Expected shaking damage in Tillsonburg: $0.022 a year per $1,000
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
With $0.022 of shaking damage a year per $1,000, Tillsonburg is about even with the typical $0.030 (0.7 times).
Shaking damage a year per $1,000 of building value
The typical town in Ontario expects $0.043 a year in shaking damage; Tillsonburg expects less, $0.022, and Alexandria the most, $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.
Tillsonburg’s earthquake risk lands near the centre of Canada’s range; 61% 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).
The loss is to Tillsonburg’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 runs high around Tillsonburg: 12% of tested homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
More homes than usual test high around Tillsonburg: 12% against 6.6% for the typical Canadian town.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Tillsonburg, 12% 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.
4.6% of Canada’s 2,611 towns have a higher share of homes over 200 Bq/m³ than Tillsonburg, 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.
A survey sample isn’t a map: any home in Tillsonburg can be high, and a three-month test is the only way to know.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Data for radon tests covers the Oxford County Health Unit
Weather and fire alerts for Tillsonburg
Environment and Climate Change Canada issues the weather alerts for Tillsonburg; 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. |
Smoke and fire warnings for Tillsonburg come through Environment Canada and Alert Ready; the fire map is CWFIS’s.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Tillsonburg’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 |
|---|---|---|---|---|
| Tillsonburg | Low | $0.022 | 12% | None listed |
| South-West Oxford 8,375 · 15 km | Low | $0.022 | 12% | None listed |
| Norwich 12,321 · 16 km | Low | $0.023 | 12% | Yes |
| Bayham 7,935 · 17 km | Low | $0.022 | 7.5% | None listed |
The neighbour with the most fire is South-West Oxford (low), still no more than Tillsonburg (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Tillsonburg faces
Practical steps for Tillsonburg’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?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
What this data can and can’t tell you
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Tillsonburg is its health region’s, the survey’s design unit.
- 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 Tillsonburg.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Tillsonburg’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; Tillsonburg’s figure is its subdivision’s.
Questions about flooding and hazards in Tillsonburg
How is Tillsonburg’s Hazard risk Grade worked out?
Tillsonburg grades C+ for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is radon a problem in Tillsonburg?
12% of the 104 homes Health Canada tested around Tillsonburg topped the guideline; your own house needs its own test.
Is Tillsonburg at risk of wildfire?
The burned-area record shows next to nothing around Tillsonburg (0% within 25 km since 1986), so its band is low.
Does Tillsonburg flood?
No study on Canada’s Flood Map Inventory covers Tillsonburg (0), which doesn’t mean it has never been mapped, so ask the municipality.
How big is the earthquake risk in Tillsonburg?
NRCan’s model expects shaking to cost buildings in Tillsonburg $0.022 a year for every $1,000 of their value, on average over many years.
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).