Photo: Veillg1 · CC BY-SA 4.0Flood mapping exists for Hudson: 1 on record, latest by Communauté métropolitaine de Montréal
The national fire record shows next to nothing around Hudson, 0% of the land within 25 km since 1986 (0.001% a year). Shaking is a bigger worry than in most places, at $0.14 a year per $1,000 of building value ($0.030 typical). Radon around Hudson is ordinary for Canada: 8.2% of tested homes over the guideline (6.6% typical). Hazard risk gives Hudson a grade of C, from earthquakes and radon alone.
What stands out about Hudson’s hazards
For Hudson, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Hudson faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Hudson: C
For Hudson, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #253 of 507 in Quebec and #2,205 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.
Wildfire is rare near Hudson: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Hudson’s residents live, and the fuel next to their homes.
The land within 25 km of Hudson burns at 0.001% a year on average, the low band; the typical Canadian town: 0.000%.
Fire has stayed at least 6.4 km from Hudson’s homes since 1986.
Forest fuel is denser close to Hudson (12% within 5 km) than further out (3.5% 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 Quebec · highest of 513
In the upper half in Quebec but far from Mistissini (0.31%): Hudson ranks 136th of 513, at 0.001% a year.
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.
Beside 2,610 Canadian towns, Hudson reads low, with 92% of them; only 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.
Communauté métropolitaine de Montréal has mapped flooding for Hudson (1 study)
Flood studies whose area touches Hudson, from NRCan’s inventory, each linked to its owner.
Communauté métropolitaine de Montréal studied flooding in an area that includes Hudson (2008); open its map to see which streets lie in a flood zone.
| Study | By | Year | Status |
|---|---|---|---|
| Montréal-Argenteuil-Deux-Montagnes-Vaudreuil-Soulanges | Communauté métropolitaine de Montréal | 2008 | final |
Towns with a flood study on file
Its flood study sets Hudson apart in Quebec, where 45% of towns have one (Canada: 58%).
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood mapping is shown for Hudson to be opened and checked, never turned into a grade.
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.
Shaking is Hudson’s costliest hazard: $0.14 a year per $1,000
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
Hudson’s $0.14 is about 4.7 times the typical town’s $0.030: it sits in one of Canada’s more active seismic zones.
Shaking damage a year per $1,000 of building value
The median in Quebec is $0.14; Hudson, at $0.14, is right beside it, and La Pocatière tops the list at $0.48.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
20% of Canada’s 2,611 towns expect more shaking damage than Hudson, 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).
For Hudson the model prices shaking damage to buildings, nothing more.
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 Hudson are over the radon guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
The survey area of Hudson reads 8.2%, a shade from the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Hudson, 8.2% of tests topped the guideline, about the same as the typical town in Quebec (8.2%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Radon tops the guideline in a modest share of homes around Hudson, a band holding 37% of Canada’s 2,611 towns; 26% 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.
Whatever Hudson’s area share, the reading that matters is your own home’s, over a winter.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Data for radon tests covers the Monteregie health region
Where to get warnings in Hudson
Alerts for Hudson 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 Hudson to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Hudson’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Hudson | Low | $0.14 | 8.2% | Yes |
| Kanesatake 1,872 · 3.8 km | Low | $0.10 | 10% | Yes |
| Saint-Lazare 22,895 · 6.3 km | Low | $0.14 | 8.2% | None listed |
| Oka 4,312 · 6.8 km | Low | $0.13 | 10% | Yes |
| Saint-Placide 1,751 · 9.2 km | Low | $0.17 | 10% | Yes |
| Vaudreuil-sur-le-Lac 1,340 · 9.8 km | Low | $0.17 | 8.2% | Yes |
| Vaudreuil-Dorion 46,413 · 11 km | Low | $0.17 | 8.2% | Yes |
Among its neighbours Hudson has the most fire on record (low); Saint-Lazare follows (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Hudson faces
Practical steps for Hudson’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?
- Check the address on the flood map.
- 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 Hudson is its health region’s, the survey’s design unit.
- 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 Hudson.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Hudson’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 Hudson.
Questions about flooding and hazards in Hudson
Is Hudson at risk of wildfire?
Not much by Canadian standards: Hudson’s band is low, with 0% of the land within 25 km burned since 1986 (last in 2024), so wildfire doesn’t change its grade.
Is radon a problem in Hudson?
8.2% of the 110 homes Health Canada tested around Hudson topped the guideline; your own house needs its own test.
Does Hudson flood?
There is flood mapping for Hudson on the national inventory, each study linked to its owner’s map, none of them graded.
How is Hudson’s Hazard risk Grade worked out?
Hudson grades C for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
How big is the earthquake risk in Hudson?
About $0.14 a year per $1,000 of building value, NRCan’s long-run expectation for Hudson.
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).