Photo: JFVoll · CC BY-SA 4.0Flood mapping exists for Watford: 1 on record, latest by St. Clair Region Conservation Authority
Wildfire barely registers for Watford, at 0% of the land within 25 km since 1986 (0.001% a year). Shaking is less of a worry than in most places, at $0.014 a year per $1,000 of building value ($0.030 typical). About as many homes carry radon around Watford as elsewhere, 8.4% over the guideline where the typical town has 6.6%. Watford grades B+ for hazard risk, with wildfire counted against it.
What stands out about Watford’s hazards
Four national sources, each read for Watford: earthquakes, radon, past fires and flood studies.
What Watford faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Watford grades B+ for hazard risk
Two inputs always count for Watford, earthquakes and radon; the third, wildfire, counts only against a town.
Its place: #468 of 866 in Ontario and #909 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 Watford has burned: 0% within 5 km, 0% within 25 km since 1986
Past fire around Watford’s homes, from the national burned-area record, with the fuel within 5 km.
With 0.001% burned a year, Watford is among the many low-band places (the typical Canadian town 0.000%).
Nothing inside 5 km of Watford’s homes has burned since 1986, and the nearest scar is 20 km off.
Forest makes up 0% of the land within 5 km of Watford and 0.4% within 25 km, little for a forest fire to run through.
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
Sioux Lookout burns fastest in Ontario at 0.16% a year; Watford, at 0.001%, ranks 83rd of 871.
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.
The low band takes in 92% of Canada’s 2,610 towns, Watford among them, though its rate is above zero; 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.
St. Clair Region Conservation Authority has mapped flooding for Watford (1 study)
What Canada’s Flood Map Inventory lists for Watford: who studied flooding and where to see their maps.
A 2009 study by St. Clair Region Conservation Authority covers Watford, and its map, not the inventory, shows the zones.
| Study | By | Year | Status |
|---|---|---|---|
| SCRCA Floodplain Estimation Study for Ontario Regulation 171-06 | St. Clair Region Conservation Authority | 2009 | final · not public |
Towns with a flood study on file
Flood maps are common in Ontario: 69% of towns have one, against 58% nationally, and Watford is among them.
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 Watford’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.
Low seismic risk in Watford: $0.014 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Watford’s $0.014 is a fraction of the typical town’s $0.030 (0.5 times as much): quiet ground by Canadian standards.
Shaking damage a year per $1,000 of building value
Earthquake risk in Ontario peaks in Alexandria ($0.21); Watford, at $0.014, 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.
73% of Canada’s 2,611 towns expect more shaking damage than Watford.
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 Watford’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).
8.4% of homes tested around Watford are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · Measured across the Lambton Health Unit: radon tests
Around Watford, 8.4% of tested homes topped the guideline, near the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
More homes top the guideline around Watford (8.4%) than in the typical town in Ontario (4%); 0.6% went over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
26% of Canada’s 2,611 towns have more homes over 200 Bq/m³ than Watford’s 5–10% band, which holds 37%.
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.
Basements, soil and how a house is sealed decide its radon, so in Watford only a test can say.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Watford
Environment and Climate Change Canada issues the weather alerts for Watford; 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 Watford 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 Watford
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Watford | Low | $0.014 | 8.4% | Yes |
| Brooke-Alvinston 2,557 · 15 km | Low | $0.018 | 8.4% | Yes |
| Adelaide-Metcalfe 3,196 · 18 km | Low | $0.018 | 1.8% | Yes |
The neighbour with the most fire is Brooke-Alvinston (low), still no more than Watford (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Watford faces
What to do about the hazards Watford 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
- 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 Watford floods.
- 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 Watford sits in.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Watford’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; Watford’s figure is its subdivision’s.
Questions about flooding and hazards in Watford
How is Watford’s Hazard risk Grade worked out?
Hazard risk gives Watford B+, weighing earthquakes and radon and counting wildfire only against it.
How big is the earthquake risk in Watford?
In NRCan’s seismic model, Watford’s buildings lose $0.014 per $1,000 of value in an average year.
Does Watford flood?
Watford’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 Watford?
In Health Canada’s survey, 8.4% of 178 homes tested in Watford’s area were above 200 Bq/m³, though only a test tells you about one house.
Is Watford at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Watford has burned since 1986, the last in 2006, 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).