Photo: Sdeschenes at English Wikipedia · CC BY-SA 3.0East Gwillimbury faces fewer hazards than 94% of Canadian towns
Little of the land around East Gwillimbury has burned: 0% within 25 km since 1986, or 0.001% a year. Earthquake risk in East Gwillimbury is ordinary: NRCan’s model puts building losses at $0.023 a year per $1,000 of value, close to the typical town’s $0.030. In Health Canada’s survey, just 0% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). East Gwillimbury grades A for hazard risk, with wildfire counted against it.
What stands out about East Gwillimbury’s hazards
Four national sources, each read for East Gwillimbury: earthquakes, radon, past fires and flood studies.
What East Gwillimbury faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
East Gwillimbury grades A for hazard risk
Seismic risk and radon set East Gwillimbury’s grade, wildfire can drag it down, and flood mapping stays out of it.
Its place: #27 of 866 in Ontario and #269 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.
Wildfire is rare near East Gwillimbury: 0% of the land within 25 km burned since 1986, 0.2% within 5 km
Past fire around East Gwillimbury’s homes, from the national burned-area record, with the fuel within 5 km.
East Gwillimbury burns at 0.001% a year, low against 0.000% for the typical Canadian town.
About as much forest grows next to East Gwillimbury’s homes (14% within 5 km) as across 25 km (12%).
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: East Gwillimbury ranks 83rd of 871 at 0.001% 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.
Low, like 92% of the country’s 2,610 towns: the land around East Gwillimbury 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.
No flood study is listed for East Gwillimbury
What Canada’s Flood Map Inventory lists for East Gwillimbury: who studied flooding and where to see their maps.
An empty entry for East Gwillimbury on the inventory isn’t proof of safety; ask locally for flood maps.
Towns with a flood study on file
Missing from a well-mapped province: East Gwillimbury 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 East Gwillimbury.
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.”
Expected shaking damage in East Gwillimbury: $0.023 a year per $1,000
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
0.8 times the typical $0.030: East Gwillimbury’s $0.023 is ordinary.
Shaking damage a year per $1,000 of building value
Earthquake risk in Ontario peaks in Alexandria ($0.21); East Gwillimbury, at $0.023, is below the median of $0.043.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
East Gwillimbury’s earthquake risk lands near the centre of Canada’s range; 54% 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).
Roads, pipes and bridges aren’t in East Gwillimbury’s figure, nor landslides or tsunami: it is buildings and shaking.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
0% of homes tested around East Gwillimbury are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
East Gwillimbury’s area, at 0%, is below the 6.6% of the typical Canadian town, though any one home can still be high. Behind radon tests sits data gathered across the York Regional Health Unit, with East Gwillimbury one part of it.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
East Gwillimbury’s area, at 0%, is below the median in Ontario (4%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Few tests over the guideline: East Gwillimbury shares the bottom band with 37% of Canada’s 2,611 towns, below the other 63%.
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 survey sample isn’t a map: any home in East Gwillimbury can be high, and a three-month test is the only way to know.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for East Gwillimbury
Environment and Climate Change Canada issues the weather alerts for East Gwillimbury; 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 East Gwillimbury, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How East Gwillimbury’s neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
None of the places around has more fire nearby than East Gwillimbury (low); Newmarket comes closest (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what East Gwillimbury faces
Practical steps for East Gwillimbury’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
- 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 East Gwillimbury.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, East Gwillimbury takes its 2007 health region’s share.
- 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 East Gwillimbury’s.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of East Gwillimbury’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 East Gwillimbury
Is radon a problem in East Gwillimbury?
The area’s survey found 0% of 95 tested homes above Health Canada’s guideline, so a three-month test is worth doing in East Gwillimbury.
Does East Gwillimbury flood?
The inventory has 0 studies for East Gwillimbury, and an empty list isn’t a clean bill: the municipality holds any flood maps.
How big is the earthquake risk in East Gwillimbury?
In NRCan’s seismic model, East Gwillimbury’s buildings lose $0.023 per $1,000 of value in an average year.
How is East Gwillimbury’s Hazard risk Grade worked out?
Hazard risk gives East Gwillimbury A, weighing earthquakes and radon and counting wildfire only against it.
Is East Gwillimbury at risk of wildfire?
Some, but East Gwillimbury’s low band (0% of nearby land burned since 1986, latest 2006) is short of the level that counts.
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).