Lemoyne’s hazards at a glance: a low wildfire record and 8.2% of area homes over the radon guideline
Burn scars are few around Lemoyne, with 0.1% of the land within 25 km touched by fire since 1986 (0.002% a year). Seismic risk runs high: $0.23 of expected damage per $1,000 of buildings a year, the typical town $0.030. Hazard risk gives Lemoyne a grade of C−, from earthquakes and radon alone.
What stands out about Lemoyne’s hazards
For Lemoyne, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Lemoyne faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Lemoyne grades C− for hazard risk
For Lemoyne, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #383 of 507 in Quebec and #2,362 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Few fires near Lemoyne: 0% within 5 km, 0.1% within 25 km
Past fire around Lemoyne’s homes, from the national burned-area record, with the fuel within 5 km.
Fire claims 0.002% of the land around Lemoyne each year, a low band, with the typical Canadian town at 0.000%.
Since 1986 the nearest fire to Lemoyne’s homes came within 9.8 km, never inside 5 km.
With 0.1% forest fuel within 5 km and 0.7% within 25 km, the land around Lemoyne gives a fire little to burn.
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 Quebec · highest of 513
Mistissini burns fastest in Quebec at 0.31% a year; Lemoyne, at 0.002%, ranks 35th of 513.
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; Lemoyne 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.
No flood study is listed for Lemoyne
What Canada’s Flood Map Inventory lists for Lemoyne: who studied flooding and where to see their maps.
The inventory has nothing for Lemoyne, but a local or conservation-authority map may still exist.
Towns with a flood study on file
Flood maps are thinner in Quebec, 45% of towns against 58% nationally, and Lemoyne has none.
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 Lemoyne’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.”
Earthquakes cost buildings in Lemoyne $0.23 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Lemoyne’s $0.23 is about 7.6 times the typical town’s $0.030: it sits in one of Canada’s more active seismic zones.
Behind earthquake risk sits data gathered across the city of Longueuil, with Lemoyne one part of it.
Shaking damage a year per $1,000 of building value
Earthquake risk in Quebec peaks in La Pocatière ($0.48); Lemoyne, at $0.23, sits above the median of $0.14.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Few of Canada’s 2,611 towns face more earthquake damage than Lemoyne: 6.4% of them.
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 Lemoyne 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).
8.2% of homes tested around Lemoyne are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
The survey area of Lemoyne reads 8.2%, a shade from the typical Canadian town’s 6.6%. Lemoyne shares its radon tests numbers with the rest of the Monteregie health region.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Lemoyne’s area, at 8.2%, is close to the median in Quebec (8.2%).
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 Lemoyne’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.
Health Canada advises testing every home, Lemoyne’s included, whatever the area’s figure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Lemoyne
Environment and Climate Change Canada issues the weather alerts for Lemoyne; 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. |
For fires near Lemoyne, the national fire information system maps danger and active fires daily; local authorities give any evacuation order.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Lemoyne
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Lemoyne | Low | $0.23 | 8.2% | None listed |
| Saint-Lambert 23,355 · 0.7 km | Low | $0.22 | 8.2% | None listed |
| Vieux Greenfield Park 10,998 · 1.8 km | Low | $0.23 | 8.2% | None listed |
| Saint-Jean-Vianney 13,181 · 2.0 km | Low | $0.23 | 8.2% | None listed |
| Laflèche 19,706 · 2.1 km | Low | $0.23 | 8.2% | None listed |
| Notre-Dame-de-la-Garde 6,671 · 2.3 km | Low | $0.23 | 8.2% | None listed |
| Notre-Dame-de-Grâces 10,204 · 2.9 km | Low | $0.23 | 8.2% | None listed |
Among its neighbours Lemoyne has the most fire on record (low); Saint-Lambert follows (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Lemoyne faces
Practical steps for Lemoyne’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.
- Drop, cover and hold on.
- Strap the water heater down.
- Keep 72 hours of supplies.
- Has it had a radon test?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
- Is earthquake cover included?
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 Lemoyne is its health region’s, the survey’s design unit.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Lemoyne’s included.
- 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 Lemoyne.
- 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 Lemoyne.
Questions about flooding and hazards in Lemoyne
How big is the earthquake risk in Lemoyne?
NRCan’s model expects shaking to cost buildings in Lemoyne $0.23 a year for every $1,000 of their value, on average over many years.
Is radon a problem in Lemoyne?
8.2% of the 110 homes Health Canada tested around Lemoyne topped the guideline; your own house needs its own test.
Is Lemoyne at risk of wildfire?
Not much by Canadian standards: Lemoyne’s band is low, with 0.1% of the land within 25 km burned since 1986 (last in 2024), so wildfire doesn’t change its grade.
How is Lemoyne’s Hazard risk Grade worked out?
Lemoyne’s Hazard risk grade is C−, built on earthquakes and radon with a one-sided wildfire input.
Does Lemoyne flood?
No study on Canada’s Flood Map Inventory covers Lemoyne (0), which doesn’t mean it has never been mapped, so ask the municipality.
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).