Photo: P199 · CC BY-SA 3.0Mono is on Canada’s flood inventory: 4 listed, led by Toronto Regional Conservation Authority
Since 1986 almost nothing has burned near Mono: 0% of the land within 25 km, or 0.000% a year. Earthquakes matter little: NRCan’s model puts building losses at $0.012 a year per $1,000 of value, against $0.030 for the typical town. Radon is higher than usual: 11% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Hazard risk gives Mono a grade of B+, from earthquakes and radon alone.
What stands out about Mono’s hazards
For Mono, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Mono faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Mono: B+
Earthquake risk and radon make Mono’s grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
Its place: #603 of 866 in Ontario and #1,382 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 Mono: 0% of the land within 25 km burned since 1986, 0% within 5 km
Past fire around Mono’s homes, from the national burned-area record, with the fuel within 5 km.
Forty years of fire maps put Mono at 0.000% a year, low next to the typical Canadian town’s 0.000%.
The ring nearest Mono is the most wooded: 22% forest fuel within 5 km against 15% 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
Little or nothing burns around Mono in a typical year; 638 of the 871 towns in Ontario share that, and Sioux Lookout leads 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.
The low band holds 92% of Canada’s 2,610 towns, and Mono sits at its very bottom; only 7.5% are 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.
Flooding around Mono is mapped in 4 studies, the newest by Toronto Regional Conservation Authority
What Canada’s Flood Map Inventory lists for Mono: who studied flooding and where to see their maps.
4 studies on the inventory touch Mono, the newest Toronto Regional Conservation Authority’s from 2021, and their areas can be large, so they say maps exist, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| Toronto Floodline Consolidation | Toronto Regional Conservation Authority | 2021 | final |
| Grand River Regulatory Floodplain | Grand River Conservation Authority | 2018 | final |
| Mill Creek | Credit Valley Conservation Authority | 2017 | final · not public |
| Credit River | Credit Valley Conservation Authority | 2007 | final · not public |
Towns with a flood study on file
Flood maps are common in Ontario: 69% of towns have one, against 58% nationally, and Mono is among them.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
The busiest decade for flood studies around Mono was the 2010s (2 of 4); they run from the 2000s to the 2020s.
Study dates as the NRCan inventory lists them, one count per study touching Mono.
Flood studies don’t enter the grade; they are listed so you can open the official map for Mono.
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.
Low seismic risk in Mono: $0.012 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
At $0.012 per $1,000, Mono carries 0.4 times the typical Canadian town’s earthquake risk ($0.030): low.
Shaking damage a year per $1,000 of building value
Mono’s $0.012 sits under the median in Ontario, $0.043, and well under Alexandria’s $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.
Mono is in the lower part of Canada’s range for earthquake risk; 84% 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).
For Mono the model prices shaking damage to buildings, nothing more.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
11% of homes tested around Mono are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · Area-wide: radon tests, counted over the Wellington-Dufferin-Guelph Health Unit
Radon runs above the typical Canadian town (6.6%) in Mono’s area, at 11%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
More homes top the guideline around Mono (11%) than in the typical town in Ontario (4%); 2% went over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
More high tests than most: Mono sits in a band that only 22% of Canada’s 2,611 towns share, with 4.6% above.
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.
Health Canada advises testing every home, Mono’s included, whatever the area’s figure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Mono
Alerts for Mono 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. |
Alert Ready carries evacuation orders for Mono to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Mono
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Mono | Low | $0.012 | 11% | Yes |
| Orangeville 33,070 · 6.9 km | Low | $0.012 | 11% | Yes |
| Amaranth 4,808 · 12 km | Low | $0.019 | 11% | Yes |
| Shelburne 10,767 · 17 km | Low | $0.019 | 11% | None listed |
| East Garafraxa 2,976 · 18 km | Low | $0.018 | 11% | Yes |
None of the places around has more fire nearby than Mono (low); Orangeville comes closest (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Mono faces
Practical steps for Mono’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
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Mono’s included.
- 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 Mono floods.
- 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 Mono sits in.
- 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 Mono.
Questions about flooding and hazards in Mono
Is radon a problem in Mono?
11% of the 99 homes Health Canada tested around Mono topped the guideline; your own house needs its own test.
Does Mono flood?
Mono’s area has been studied for flooding, and the owner’s map shows which streets lie in a zone; the grade leaves flood out.
How big is the earthquake risk in Mono?
NRCan’s model expects shaking to cost buildings in Mono $0.012 a year for every $1,000 of their value, on average over many years.
Is Mono at risk of wildfire?
The burned-area record shows next to nothing around Mono (0% within 25 km since 1986), so its band is low.
How is Mono’s Hazard risk Grade worked out?
Hazard risk gives Mono 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).