Photo: JFVoll · CC BY-SA 4.0A flood study covers Sheldon: 5 on the national inventory, the newest from Hamilton Conservation Authority
Since 1986 almost nothing has burned near Sheldon: 0% of the land within 25 km, or 0.000% a year. NRCan expects $0.044 of shaking damage a year per $1,000 of buildings in Sheldon, near the typical $0.030. Sheldon’s survey area, 5% over the radon guideline, is close to the typical town’s 6.6%. Hazard risk gives Sheldon a grade of B+, from earthquakes and radon alone.
What stands out about Sheldon’s hazards
For Sheldon, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Sheldon faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Sheldon grades B+ for hazard risk
Seismic risk and radon set Sheldon’s grade, wildfire can drag it down, and flood mapping stays out of it.
Its place: #494 of 866 in Ontario and #1,255 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.
Few fires near Sheldon: 0% within 5 km, 0% within 25 km
Past fire around Sheldon’s homes, from the national burned-area record, with the fuel within 5 km.
Fire claims 0.000% of the land around Sheldon each year, a low band, with the typical Canadian town at 0.000%.
Forest makes up 0.5% of the land within 5 km of Sheldon and 1.1% 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 has the highest burn rate in Ontario, 0.16% a year; around Sheldon, as around 638 of the 871 towns, it rounds to zero.
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; Sheldon 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.
5 flood studies cover Sheldon, the newest from Hamilton Conservation Authority
What Canada’s Flood Map Inventory lists for Sheldon: who studied flooding and where to see their maps.
The newest of 5 studies covering Sheldon is Hamilton Conservation Authority’s, from 2025; open its map to see the zones.
| Study | By | Year | Status |
|---|---|---|---|
| Red Hill Creek | Hamilton Conservation Authority | 2025 | final |
| Welland River | Niagara Peninsula Conservation Authority | 2018 | final |
| Grand River Regulatory Floodplain | Grand River Conservation Authority | 2018 | final |
| Twenty Mile Creek | Niagara Peninsula Conservation Authority | 2007 | final |
| ThreeMileCreek | Niagara Peninsula Conservation Authority | final |
Towns with a flood study on file
Flood maps are common in Ontario: 69% of towns have one, against 58% nationally, and Sheldon is among them.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Studies touching Sheldon run from the 2000s to the 2020s, with the most in the 2010s: 2 of 4.
Study dates as the NRCan inventory lists them, one count per study touching Sheldon.
Listed, not scored: a flood study proves a map exists, not that Sheldon floods.
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.
Ordinary seismic risk in Sheldon: $0.044 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
With $0.044 of shaking damage a year per $1,000, Sheldon is about even with the typical $0.030 (1.5 times).
Shaking damage a year per $1,000 of building value
About level with the typical town in Ontario: Sheldon’s $0.044 against $0.043; Alexandria reaches $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.
32% of Canada’s 2,611 towns expect more shaking damage than Sheldon, which places it in the upper third.
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).
Only shaking damage to buildings in Sheldon is counted; landslides, liquefaction, tsunami and fire after a quake aren’t.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean). · Earthquake risk: the city of Hamilton
5% of homes tested around Sheldon are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
5% of tested homes around Sheldon were over the guideline, much like the typical Canadian town at 6.6%. Sheldon doesn’t get its own radon tests figures; the ones here come from the City of Hamilton Health Unit.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
More homes top the guideline around Sheldon (5%) than in the typical town in Ontario (4%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
37% of Canada’s 2,611 towns share Sheldon’s band of 5 to 10%; 26% sit 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.
Radon varies from house to house in Sheldon, so the survey is a reason to test, not a result for yours.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Sheldon
Alerts for Sheldon 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. |
Alert Ready carries evacuation orders for Sheldon to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Sheldon
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
Sheldon’s low band tops its neighbours; Butler is next (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Sheldon faces
Practical steps for Sheldon’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. Radon figures pool the survey’s home tests by area: postal areas once their boundaries arrive, the 2007 health region around Sheldon until then.
- Wildfire counts one way. For Sheldon, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Sheldon without grading them.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Sheldon’s census subdivision (a neighbourhood shows its city’s).
Questions about flooding and hazards in Sheldon
Is Sheldon at risk of wildfire?
The burned-area record shows next to nothing around Sheldon (0% within 25 km since 1986), so its band is low.
Does Sheldon flood?
A flood study covers Sheldon on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
Is radon a problem in Sheldon?
5% of the 100 homes Health Canada tested around Sheldon topped the guideline; your own house needs its own test.
How is Sheldon’s Hazard risk Grade worked out?
Sheldon’s Hazard risk grade is B+, built on earthquakes and radon with a one-sided wildfire input.
How big is the earthquake risk in Sheldon?
NRCan’s model expects shaking to cost buildings in Sheldon $0.044 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).