Photo: University of the Fraser Valley · CC BY 2.0Shaking costs buildings in Chilliwack $0.31 a year per $1,000 of value, 10 times the typical town’s
Fire seldom reaches Chilliwack: since 1986, 0.5% of the land within 25 km has burned (0.01% a year). Fewer homes than usual carry radon here, 3% over the guideline where the typical town has 6.6%. Hazard risk gives Chilliwack a grade of C+; its wildfire band pulls it down.
What stands out about Chilliwack’s hazards
For Chilliwack, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Chilliwack faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Chilliwack: C+
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Chilliwack with little fire nearby would get no credit for it.
Its place: #207 of 254 in British Columbia and #1,844 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.
Wildfire is rare near Chilliwack: 0.5% of the land within 25 km burned since 1986, 0.4% within 5 km
Past fire around Chilliwack’s homes, from the national burned-area record, with the fuel within 5 km.
Forty years of fire maps put Chilliwack at 0.01% a year, low next to the typical Canadian town’s 0.000%.
There is forest near Chilliwack’s homes (34% within 5 km) and more of it further out (61% 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 British Columbia · highest of 255
Chilliwack burns at 0.01% a year, 87th of 255 towns in British Columbia; the leader, Oliver, reaches 0.98%.
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.
Some fire is mapped around Chilliwack, but not enough to leave the low band, where 92% of Canada’s 2,610 towns are; 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.
3 flood studies cover Chilliwack, the newest from Province of B.C. - Water, Lands, and Resource Stewardship
What Canada’s Flood Map Inventory lists for Chilliwack: who studied flooding and where to see their maps.
Province of B.C. - Water, Lands, and Resource Stewardship and others have studied flooding in areas that include Chilliwack: 3 studies, the latest from 2025.
| Study | By | Year | Status |
|---|---|---|---|
| Lower Fraser and Coquihalla Rivers | Province of B.C. - Water, Lands, and Resource Stewardship | 2025 | final |
| Vedder River Floodplain Mapping | Ministry of Environment and Climate Change Strategy | 1985 | final |
| Chilliwack River Floodplain Mapping (Vedder River to Slesse Creek ) | Ministry of Environment and Climate Change Strategy | 1981 | final |
Towns with a flood study on file
76% of towns in British Columbia have a flood study, more than Canada’s 58%; Chilliwack has one too.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Studies touching Chilliwack run from the 1980s to the 2020s, with the most in the 1980s: 2 of 3.
Study dates as the NRCan inventory lists them, one count per study touching Chilliwack.
Nothing here counts toward Risk; the studies are pointers to the maps their owners keep for Chilliwack.
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.
High seismic risk in Chilliwack: $0.31 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
At $0.31 per $1,000, Chilliwack carries roughly 10.3 times the typical Canadian town’s earthquake risk ($0.030).
Shaking damage a year per $1,000 of building value
Neither high nor low in British Columbia: Chilliwack’s $0.31 sits by the median of $0.36, while Duncan reaches $1.33.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Few of Canada’s 2,611 towns face more earthquake damage than Chilliwack: 5.9% of them.
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 Chilliwack 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).
Little radon around Chilliwack: 3% of area homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · Measured across the Fraser East health region: radon tests
Where the typical Canadian town has 6.6% of homes over the guideline, Chilliwack’s area has fewer, 3%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Chilliwack’s area, at 3%, is above the median in British Columbia (1.8%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
The quietest radon band, under 5%, holds 37% of Canada’s 2,611 towns and Chilliwack; 63% sit 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.
Whatever Chilliwack’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 Chilliwack
Environment and Climate Change Canada issues the weather alerts for Chilliwack; 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. |
For fires near Chilliwack, the national fire information system maps danger and active fires daily; local authorities give any evacuation order.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Chilliwack’s neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Chilliwack | Low | $0.31 | 3% | Yes |
| Skowkale 1,114 · 1.3 km | Low | $0.25 | 3% | None listed |
| Tzeachten 13 4,899 · 3.0 km | Low | $0.28 | 3% | Yes |
| Electoral Area E, Fraser Valley 1,748 · 11 km | Low | $0.19 | 3% | Yes |
| Cultus Lake 2,773 · 13 km | Low | $0.28 | 3% | Yes |
| Electoral Area C, Fraser Valley 1,155 · 13 km | Low | $0.082 | 3% | Yes |
| Rosedale 2,401 · 15 km | Low | $0.10 | 3% | Yes |
Electoral Area C, Fraser Valley burns a little more than Chilliwack, in the same low band (low here).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Chilliwack faces
What to do about the hazards Chilliwack 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.
- Drop, cover and hold on.
- Strap the water heater down.
- Keep 72 hours of supplies.
- Has it had a radon test?
- Check the address on the flood map.
- Are flood and wildfire insured?
- Is earthquake cover included?
What this data can and can’t tell you
- 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 Chilliwack.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Chilliwack without grading them.
- 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 Chilliwack until then.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Chilliwack’s included.
Questions about flooding and hazards in Chilliwack
Is Chilliwack at risk of wildfire?
Less than most of Canada: 0.5% of the land within 25 km of Chilliwack has burned since 1986, the last in 2023, a low band that leaves Risk alone.
How big is the earthquake risk in Chilliwack?
In NRCan’s seismic model, Chilliwack’s buildings lose $0.31 per $1,000 of value in an average year.
How is Chilliwack’s Hazard risk Grade worked out?
Hazard risk gives Chilliwack C+, weighing earthquakes and radon and counting wildfire only against it.
Does Chilliwack flood?
A flood study covers Chilliwack on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
Is radon a problem in Chilliwack?
In Health Canada’s survey, 3% of 100 homes tested in Chilliwack’s area were above 200 Bq/m³, though only a test tells you about one house.
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).