Photo: Earth Science and Remote Sensing Unit , Lyndon B. Johnson Space Center · Public domainHigh radon around Nelson: 29% of homes tested in the area exceed 200 Bq/m³
Burn scars are few around Nelson, with 1.9% of the land within 25 km touched by fire since 1986 (0.05% a year). Shaking is about as much of a worry in Nelson as in most places, at $0.050 a year per $1,000 of building value ($0.030 typical). Hazard risk gives Nelson a grade of D; its wildfire band pulls it down.
What stands out about Nelson’s hazards
For Nelson, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Nelson faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Nelson: D
For Nelson, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
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.
Little of the land around Nelson has burned: 1.2% within 5 km, 1.9% within 25 km since 1986
Past fire around Nelson’s homes, from the national burned-area record, with the fuel within 5 km.
Around Nelson fire takes 0.05% of the land in a typical year, the typical Canadian town 0.000%, which is low.
Near or far, forest fuel covers a similar share around Nelson: 93% within 5 km and 91% 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 New Brunswick · highest of 61
At 0.05% a year, Nelson is near the top in New Brunswick: 10th of 61, behind Tracadie (0.28%).
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.
Low, like 92% of the country’s 2,610 towns: the land around Nelson burns, but slower than in the 7.5% above it.
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.
Nelson is on the flood map inventory: 1 study, by Service New Brunswick - GeoNB
What Canada’s Flood Map Inventory lists for Nelson: who studied flooding and where to see their maps.
One study on the inventory touches Nelson, Service New Brunswick - GeoNB’s from 2020, and its area can be large, so it says a map exists, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| Inland Flood Mapping in New Brunswick and Updated Sea-Level Rise and Flooding Estimates for New Brunswick Coastal Sections 2020 | Service New Brunswick - GeoNB | 2020 | final |
Towns with a flood study on file
Its flood study puts Nelson with 93% of towns in New Brunswick; Canada’s share is 58%.
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 Nelson.
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.
Ordinary seismic risk in Nelson: $0.050 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
With $0.050 of shaking damage a year per $1,000, Nelson is about even with the typical $0.030 (1.7 times).
Shaking damage a year per $1,000 of building value
The typical town in New Brunswick expects $0.036 a year; Nelson expects $0.050, and St. Stephen $0.16.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Nelson sits above most of Canada’s 2,611 towns on earthquake risk; 31% 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).
What a quake does after the shaking, fire, landslides, tsunami, falls outside NRCan’s figure for Nelson.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Test for radon in Nelson: 29% of area homes were over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
Nelson’s area, at 29%, is above the 6.6% of the typical Canadian town, so testing is worth more here than most places. Nobody publishes radon tests for Nelson alone, so this card uses the figure for the Region 7 health region.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
More homes top the guideline around Nelson (29%) than in the typical town in New Brunswick (20%); 5% went over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Nelson is in the 20–30% band, which holds only 3.1% of Canada’s 2,611 towns; 1.5% are 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.
A low area share in Nelson doesn’t clear a house, nor does a high one condemn it: test.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Nelson
Environment and Climate Change Canada issues the weather alerts for Nelson; 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 Nelson, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Nelson
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Nelson | Low | $0.050 | 29% | Yes |
| Southesk 1,748 · 11 km | Low | $0.079 | 29% | Yes |
| Northesk 2,301 · 15 km | Moderate | $0.078 | 29% | Yes |
| Blackville 2,104 · 15 km | Low | $0.050 | 29% | Yes |
| Rogersville 1,131 · 18 km | Low | $0.053 | 29% | None listed |
The heaviest fire record nearby is Northesk’s, moderate to Nelson’s low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Nelson faces
Practical steps for Nelson’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?
- Check the address on the flood map.
- Are flood and wildfire insured?
What this data can and can’t tell you
- Flood studies aren’t flood zones. The flood inventory points to maps; it is incomplete and not the official source, so ask the municipality about any street in Nelson.
- Wildfire counts one way. For Nelson, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Nelson’s census subdivision (a neighbourhood shows its city’s).
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Nelson takes its 2007 health region’s share.
Questions about flooding and hazards in Nelson
Does Nelson flood?
The inventory lists a study touching Nelson; whether a given street floods is on that map, not in the grade.
How is Nelson’s Hazard risk Grade worked out?
Nelson’s Hazard risk grade is D, built on earthquakes and radon with a one-sided wildfire input.
Is radon a problem in Nelson?
29% of the 200 homes Health Canada tested around Nelson topped the guideline; your own house needs its own test.
How big is the earthquake risk in Nelson?
In NRCan’s seismic model, Nelson’s buildings lose $0.050 per $1,000 of value in an average year.
Is Nelson at risk of wildfire?
Not much by Canadian standards: Nelson’s band is low, with 1.9% of the land within 25 km burned since 1986 (last in 2025), so wildfire doesn’t change its grade.
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).