Wildfire low, radon 5%: how Marritt stands on hazards
For Marritt, wildfire history is close to nil: 0% of nearby land since 1986, 0.000% a year. Seismic risk in Marritt sits near the middle: $0.044 of expected damage per $1,000 of buildings a year, the typical town $0.030. Marritt grades B+ for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Marritt’s hazards
Four national sources, each read for Marritt: earthquakes, radon, past fires and flood studies.
What Marritt faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Marritt grades B+ for hazard risk
Earthquake risk and radon make Marritt’s grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
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. Small fires and grass fires are largely missing from the national burned-area record.
Wildfire is rare near Marritt: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Marritt’s residents live, and the fuel next to their homes.
With 0.000% burned a year, Marritt is among the many low-band places (the typical Canadian town 0.000%).
Around Marritt the forest is thin or far off: 0.9% of the land within 5 km and 1.6% within 25 km is forest fuel.
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 Marritt, 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.
Marritt shares the low band with 92% of Canada’s 2,610 towns, its burn rate rounding to nothing; 7.5% burn faster.
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.
The flood map inventory lists nothing for Marritt
Flood studies whose area touches Marritt, from NRCan’s inventory, each linked to its owner.
Nationally, Marritt has no listed flood study; the municipality is the place to ask.
Towns with a flood study on file
69% of towns in Ontario have a flood study, more than Canada’s 58%; Marritt is not yet one of them.
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 Marritt.
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 Marritt $0.044 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.
Marritt’s $0.044 is close to the typical town’s $0.030 (1.5 times as much).
For earthquake risk, the only official count covers all of the city of Hamilton, Marritt included.
Shaking damage a year per $1,000 of building value
Neither high nor low in Ontario: Marritt’s $0.044 sits by the median of $0.043, while 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.
In the upper part of Canada’s range: 32% of its 2,611 towns expect more damage than Marritt.
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).
Roads, pipes and bridges aren’t in Marritt’s figure, nor landslides or tsunami: it is buildings and shaking.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Some radon around Marritt: 5% of area homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Radon tests for the City of Hamilton Health Unit
Around Marritt, 5% of tested homes topped the guideline, near the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
The median in Ontario is 4% over 200 Bq/m³; the survey area around Marritt has 5%.
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 Marritt, 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.
A survey sample isn’t a map: any home in Marritt can be high, and a three-month test is the only way to know.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Marritt
Environment and Climate Change Canada issues the weather alerts for Marritt; 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 Marritt 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 Marritt
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Marritt | Low | $0.044 | 5% | None listed |
| Oakes 4,048 · 0.9 km | Low | $0.044 | 5% | None listed |
| Garner 5,456 · 1.4 km | Low | $0.044 | 5% | None listed |
| Horning 4,587 · 1.9 km | Low | $0.044 | 5% | None listed |
| Lampman 5,663 · 2.1 km | Low | $0.044 | 5% | None listed |
| Sulphur Springs 9,404 · 2.5 km | Low | $0.044 | 5% | None listed |
| Leeming 2,849 · 2.8 km | Low | $0.044 | 5% | Yes |
None of the places around has more fire nearby than Marritt (low); Oakes comes closest (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Marritt faces
Practical steps for Marritt’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?
- Ask the municipality for flood maps.
- 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 Marritt 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 Marritt sits in.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Marritt’s homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- Earthquakes are modelled. Shaking damage is modelled from the ground, the buildings and the odds of each quake, and published for whole subdivisions such as Marritt’s.
Questions about flooding and hazards in Marritt
How is Marritt’s Hazard risk Grade worked out?
Marritt grades B+ for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is Marritt at risk of wildfire?
Hardly at all on record: 0% of the land within 25 km of Marritt since 1986, a low band, though small grass fires aren’t mapped.
How big is the earthquake risk in Marritt?
Expected earthquake damage in Marritt comes to $0.044 a year for each $1,000 that buildings are worth.
Is radon a problem in Marritt?
5% of the 100 homes Health Canada tested around Marritt topped the guideline; your own house needs its own test.
Does Marritt flood?
No study on Canada’s Flood Map Inventory covers Marritt (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).