Photo: Ken Lund from Reno, Nevada, USA · CC BY-SA 2.0Sandwich is on Canada’s flood inventory: 1 listed, led by Essex Region Conservation Authority / County of Essex
Little of the land around Sandwich has burned: 0.2% within 25 km since 1986, or 0.007% a year. Earthquake risk in Sandwich is ordinary: NRCan’s model puts building losses at $0.019 a year per $1,000 of value, close to the typical town’s $0.030. More homes than usual carry radon here, 14% over the guideline where the typical town has 6.6%. Sandwich grades C+ for hazard risk, with wildfire counted against it.
What stands out about Sandwich’s hazards
Four national sources, each read for Sandwich: earthquakes, radon, past fires and flood studies.
What Sandwich faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Sandwich: C+
Seismic risk and radon set Sandwich’s grade, wildfire can drag it down, and flood mapping stays out of it.
Its place: #682 of 866 in Ontario and #1,870 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 Sandwich has burned: 1.5% within 5 km, 0.2% within 25 km since 1986
Fires mapped since 1986 around where Sandwich’s residents live, and the fuel next to their homes.
Sandwich burns at 0.007% a year, low against 0.000% for the typical Canadian town.
Little near Sandwich’s homes can carry a forest fire; only 0.2% of the land within 5 km is forest fuel, and 0.4% 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
At 0.007% a year, Sandwich is near the top in Ontario: 32nd of 871, behind Sioux Lookout (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; Sandwich 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 Sandwich, from Essex Region Conservation Authority / County of Essex: 1 on the inventory
Flood studies whose area touches Sandwich, from NRCan’s inventory, each linked to its owner.
One study on the inventory touches Sandwich, Essex Region Conservation Authority / County of Essex’s from 2024, and its area can be large, so it says a map exists, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| Essex Region | Essex Region Conservation Authority / County of Essex | 2024 | final |
Towns with a flood study on file
69% of towns in Ontario have a flood study, more than Canada’s 58%; Sandwich has one too.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Nothing here counts toward Risk; the studies are pointers to the maps their owners keep for Sandwich.
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 Sandwich $0.019 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.
Earthquake losses in Sandwich, $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
Earthquake risk in Ontario peaks in Alexandria ($0.21); Sandwich, at $0.019, is below the median of $0.043.
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 (66%) face more earthquake damage than Sandwich.
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 Sandwich’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). · Not measured by town: earthquake risk (the city of Windsor)
Test for radon in Sandwich: 14% of area homes were over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Area-wide: radon tests, counted over the Windsor-Essex County Health Unit
the typical Canadian town has 6.6% over the guideline; Sandwich’s area has 14%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Sandwich than in most towns in Ontario: 14% over the guideline (4% is typical), 1% over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
The 10–20% band holds 22% of Canada’s 2,611 towns, Sandwich among them; 4.6% 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.
One home in Sandwich can be high while next door is low; a three-month test settles it.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Sandwich
Environment and Climate Change Canada issues the weather alerts for Sandwich; 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 Sandwich come through Environment Canada and Alert Ready; the fire map is CWFIS’s.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Sandwich
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Sandwich | Low | $0.019 | 14% | Yes |
| River West 13,940 · 2.1 km | Low | $0.019 | 14% | Yes |
| South Cameron 11,804 · 2.3 km | Low | $0.019 | 14% | None listed |
| South Central 10,392 · 3.4 km | Low | $0.019 | 14% | None listed |
| City Centre 10,269 · 3.5 km | Low | $0.019 | 14% | Yes |
| South Windsor 15,896 · 4.9 km | Low | $0.019 | 14% | Yes |
| Walkerville 19,541 · 4.9 km | Low | $0.019 | 14% | Yes |
River West burns a little more than Sandwich, in the same low band (low here).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Sandwich faces
Practical steps for Sandwich’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
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Sandwich’s figure is its subdivision’s.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Sandwich takes its 2007 health region’s share.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Sandwich’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Flood studies aren’t flood zones. The flood inventory points to maps; it is incomplete and not the official source, so ask the municipality about any street in Sandwich.
Questions about flooding and hazards in Sandwich
Is radon a problem in Sandwich?
The area’s survey found 14% of 195 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Sandwich.
Does Sandwich flood?
The inventory lists a study touching Sandwich; whether a given street floods is on that map, not in the grade.
How is Sandwich’s Hazard risk Grade worked out?
Sandwich grades C+ for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is Sandwich at risk of wildfire?
Some, but Sandwich’s low band (0.2% of nearby land burned since 1986, latest 2010) is short of the level that counts.
How big is the earthquake risk in Sandwich?
Expected earthquake damage in Sandwich comes to $0.019 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).