Photo: Quintin Soloviev · CC BY 4.0Dryden’s hazards at a glance: a low wildfire record and 14% of area homes over the radon guideline
Fire seldom reaches Dryden: since 1986, 0.1% of the land within 25 km has burned (0.002% a year). Shaking is less of a worry than in most places, at $0.006 a year per $1,000 of building value ($0.030 typical). Dryden grades B for hazard risk, with wildfire counted against it.
What stands out about Dryden’s hazards
Four national sources, each read for Dryden: earthquakes, radon, past fires and flood studies.
What Dryden faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Dryden: B
For Dryden, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #614 of 866 in Ontario and #1,405 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Small fires and grass fires are largely missing from the national burned-area record.
Little of the land around Dryden has burned: 0% within 5 km, 0.1% within 25 km since 1986
Fires mapped since 1986 around where Dryden’s residents live, and the fuel next to their homes.
A burn rate of 0.002% a year keeps Dryden in the low band (the typical Canadian town: 0.000%).
Since 1986 the nearest fire to Dryden’s homes came within 8.9 km, never inside 5 km.
Forest thickens with distance from Dryden: 59% of the land within 5 km, 73% 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
At 0.002% a year, Dryden is near the top in Ontario: 54th of 871, behind Sioux Lookout (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.
7.5% of Canada’s 2,610 towns burn fast enough to rank moderate or above; Dryden 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 Dryden
Flood studies whose area touches Dryden, from NRCan’s inventory, each linked to its owner.
There is no study for Dryden on the national flood inventory, which is far from complete.
Towns with a flood study on file
Dryden has no flood study on file, though 69% of towns in Ontario do (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 Dryden 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.”
Earthquakes cost buildings in Dryden just $0.006 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.
Shaking costs the typical town $0.030 a year; in Dryden it is only $0.006, 0.2 times as much.
Shaking damage a year per $1,000 of building value
At $0.006, Dryden 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.
Most of Canada’s 2,611 towns (88%) face more earthquake damage than Dryden.
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).
The model counts damage to Dryden’s buildings and their occupants from shaking only: not liquefaction, landslides, tsunami or fires after a quake.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Radon runs high around Dryden: 14% of tested homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · The radon tests numbers here cover the Northwestern Health Unit
the typical Canadian town has 6.6% over the guideline; Dryden’s area has 14%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Dryden’s area, at 14%, is above the median in Ontario (4%), and 1.9% of its tests passed 600 Bq/m³.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
One test in ten or more tops the guideline around Dryden, as in 22% of Canada’s 2,611 towns; 4.6% go 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.
One home in Dryden can be high while next door is low; a three-month test settles it.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Dryden
Alerts for Dryden 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. |
Fire danger and active fires near Dryden are mapped daily by the Canadian Wildland Fire Information System; evacuation orders come from the municipality or province.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Get ready for what Dryden faces
Practical steps for Dryden’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
- 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 Dryden’s.
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Dryden is its health region’s, the survey’s design unit.
- 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 Dryden.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Dryden’s homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
Questions about flooding and hazards in Dryden
How big is the earthquake risk in Dryden?
About $0.006 a year per $1,000 of building value, NRCan’s long-run expectation for Dryden.
Does Dryden flood?
The inventory has 0 studies for Dryden, and an empty list isn’t a clean bill: the municipality holds any flood maps.
Is radon a problem in Dryden?
The area’s survey found 14% of 210 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Dryden.
Is Dryden at risk of wildfire?
Some, but Dryden’s low band (0.1% of nearby land burned since 1986, latest 2003) is short of the level that counts.
How is Dryden’s Hazard risk Grade worked out?
Hazard risk gives Dryden B, 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).