Photo: Earth Science and Remote Sensing Unit , Lyndon B. Johnson Space Center · Public domainAround Thompson, 43% of tested homes have radon above the guideline
Since 1986 almost nothing has burned near Thompson: 0% of the land within 25 km, or 0.000% a year. Earthquakes matter little: NRCan’s model puts building losses at $0.004 a year per $1,000 of value, against $0.030 for the typical town. Hazard risk gives Thompson a grade of B, from earthquakes and radon alone.
What stands out about Thompson’s hazards
Four national sources, each read for Thompson: earthquakes, radon, past fires and flood studies.
What Thompson faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Thompson grades B for hazard risk
For Thompson, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
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 Thompson: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Thompson’s residents live, and the fuel next to their homes.
Forty years of fire maps put Thompson at 0.000% a year, low next to the typical Canadian town’s 0.000%.
Thompson’s homes have had no fire within 5 km since 1986; the closest was 16 km away.
Land that isn’t forest covers nearly all the ground around Thompson: forest fuel is 0% within 5 km and 0% 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 Manitoba · highest of 190
Near-zero burning puts Thompson with 61 of the 190 towns in Manitoba, far below Flin Flon (Part) at 1.68%.
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.
Most of the country’s 2,610 towns are low-band (92%, against 7.5% above); around Thompson, burning rounds to zero.
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 Thompson
Flood studies whose area touches Thompson, from NRCan’s inventory, each linked to its owner.
Nationally, Thompson has no listed flood study; the municipality is the place to ask.
Towns with a flood study on file
Flood maps are thinner in Manitoba, 18% of towns against 58% nationally, and Thompson has none.
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 Thompson 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.”
Little shaking expected in Thompson: $0.004 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.
At $0.004 per $1,000, Thompson carries 0.1 times the typical Canadian town’s earthquake risk ($0.030): low.
Shaking damage a year per $1,000 of building value
Earthquake risk in Manitoba peaks in Virden ($0.007); Thompson, at $0.004, is below the median of $0.006.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Nearly every one of Canada’s 2,611 towns (98%) expects more shaking damage than Thompson.
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 Thompson’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 Thompson: 43% of tested homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Measured across the Central health region: radon tests
the typical Canadian town has 6.6% over the guideline; Thompson’s area has 43%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Thompson than in most towns in Manitoba: 43% over the guideline (12% is typical), 7.4% over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
No band is higher: Thompson is among the 1.5% of Canada’s towns with 30% or more of tests over 200 Bq/m³.
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.
Basements, soil and how a house is sealed decide its radon, so in Thompson only a test can say.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Thompson
Alerts for Thompson 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. |
Evacuation orders for Thompson come from the municipality or the province, while CWFIS maps fire danger every day.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Get ready for what Thompson faces
Practical steps for Thompson’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 Thompson’s.
- 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 Thompson sits in.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Thompson’s homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- 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 Thompson floods.
Questions about flooding and hazards in Thompson
Is Thompson at risk of wildfire?
Not much by Canadian standards: Thompson’s band is low, with 0% of the land within 25 km burned since 1986 (last in 2003), so wildfire doesn’t change its grade.
How big is the earthquake risk in Thompson?
Expected earthquake damage in Thompson comes to $0.004 a year for each $1,000 that buildings are worth.
Does Thompson flood?
No study on Canada’s Flood Map Inventory covers Thompson (0), which doesn’t mean it has never been mapped, so ask the municipality.
How is Thompson’s Hazard risk Grade worked out?
Thompson’s Hazard risk grade is B, built on earthquakes and radon with a one-sided wildfire input.
Is radon a problem in Thompson?
43% of the 108 homes Health Canada tested around Thompson topped the guideline; your own house needs its own test.
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).