Photo: P199 · Public domainMarkstay-Warren’s hazards at a glance: a low wildfire record and 5.2% of area homes over the radon guideline
Wildfire is rare near Markstay-Warren: 0.2% of the land within 25 km has burned since 1986, a burn rate of 0.004% a year. Seismic risk in Markstay-Warren sits near the middle: $0.028 of expected damage per $1,000 of buildings a year, the typical town $0.030. Markstay-Warren grades A− for hazard risk, with wildfire counted against it.
What stands out about Markstay-Warren’s hazards
For Markstay-Warren, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Markstay-Warren faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Markstay-Warren grades A− for hazard risk
The grade weighs Markstay-Warren’s seismic risk and radon equally, and wildfire is one-sided: a high band counts against a town, a low one earns nothing.
Its place: #449 of 866 in Ontario and #872 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 Markstay-Warren: 0.2% within 5 km, 0.2% within 25 km
Past fire around Markstay-Warren’s homes, from the national burned-area record, with the fuel within 5 km.
Low by Canadian standards: 0.004% of the land a year around Markstay-Warren, 0.000% for the typical Canadian town.
Forest crowds in on Markstay-Warren: 47% of the land within 5 km is forest fuel, more than the 39% 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 Ontario · highest of 871
In the top quarter in Ontario: Markstay-Warren ranks 45th of 871 at 0.004% a year, with Sioux Lookout first at 0.16%.
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, Markstay-Warren 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.
The flood map inventory lists nothing for Markstay-Warren
What Canada’s Flood Map Inventory lists for Markstay-Warren: who studied flooding and where to see their maps.
Nationally, Markstay-Warren has no listed flood study; the municipality is the place to ask.
Towns with a flood study on file
Missing from a well-mapped province: Markstay-Warren has no study, where 69% of towns in Ontario have one against 58% nationally.
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 Markstay-Warren.
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 Markstay-Warren $0.028 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
With $0.028 of shaking damage a year per $1,000, Markstay-Warren is about even with the typical $0.030 (0.9 times).
Shaking damage a year per $1,000 of building value
At $0.028, Markstay-Warren is below the typical town in Ontario ($0.043); Alexandria is highest at $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.
Markstay-Warren’s earthquake risk lands near the centre of Canada’s range; 51% of the 2,611 towns are higher.
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 Markstay-Warren 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).
Radon about average around Markstay-Warren: 5.2% over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · The radon tests numbers here cover the Sudbury and District Health Unit
Near the middle for radon: Markstay-Warren’s area 5.2%, the typical Canadian town 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Markstay-Warren than in most towns in Ontario: 5.2% over the guideline (4% is typical), 1% over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Markstay-Warren is in the 5–10% band with 37% of Canada’s 2,611 towns; 26% have more.
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 Markstay-Warren’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).
Where to get warnings in Markstay-Warren
Environment and Climate Change Canada issues the weather alerts for Markstay-Warren; 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. |
In fire season, check CWFIS for danger and active fires around Markstay-Warren, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Markstay-Warren
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Markstay-Warren | Low | $0.028 | 5.2% | None listed |
| St.-Charles 1,654 · 15 km | Low | $0.029 | 5.2% | None listed |
The fire record around St.-Charles is a touch heavier than Markstay-Warren’s, but the band is the same: low (here low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Markstay-Warren faces
What to do about the hazards Markstay-Warren 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?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
What this data can and can’t tell you
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Markstay-Warren’s included.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Markstay-Warren without grading them.
- 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 Markstay-Warren.
- 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 Markstay-Warren until then.
Questions about flooding and hazards in Markstay-Warren
How big is the earthquake risk in Markstay-Warren?
In NRCan’s seismic model, Markstay-Warren’s buildings lose $0.028 per $1,000 of value in an average year.
Is Markstay-Warren at risk of wildfire?
Fire has reached 0.2% of the land around Markstay-Warren since 1986 (last in 2022); at low, it neither helps nor hurts the grade.
Is radon a problem in Markstay-Warren?
Around Markstay-Warren, 97 survey homes were tested and 5.2% came in over 200 Bq/m³, a guide to the area, not to any one home.
Does Markstay-Warren flood?
With 0 studies on the inventory, Markstay-Warren’s flood risk is unmapped nationally; check with the municipality before buying.
How is Markstay-Warren’s Hazard risk Grade worked out?
Hazard risk gives Markstay-Warren A−, weighing earthquakes and radon and counting wildfire only against it.
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).