Radon Levels by Province: A Canadian Guide

Radon comes from uranium and radium in the ground. Some parts of Canada sit on geology that produces far more radon than others, which makes where you live a real factor in your risk, though not the only one.

The 2024 Cross-Canada survey tested radon in about 70,000 homes, the largest national dataset on indoor radon in Canada. It found about 18% of homes above Health Canada's 200 Bq/m³ guideline, well up from Health Canada's own 2009 to 2011 survey. The percentages below are from the 2024 survey.

Here's what the data shows.

Saskatchewan

Saskatchewan has some of the highest indoor radon concentrations of any province. The geology, particularly the Canadian Shield and ancient sedimentary rock, releases radon at higher rates than most of the country.

The survey found roughly 33% of Saskatchewan homes had radon above 200 Bq/m³, nearly twice the national average. In some areas, the proportion is even higher.

Average indoor level: ~200+ Bq/m³

If you're in Saskatchewan and haven't tested, testing is one of the highest-priority actions you can take for your family's health.

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Manitoba

Manitoba's radon situation mirrors Saskatchewan's. The provincial geology, particularly in southern Manitoba and Winnipeg, produces elevated radon. The survey found roughly 43% of Manitoba homes exceeded 200 Bq/m³, the highest rate of any province.

Winnipeg has been the focus of specific radon awareness campaigns. Readings vary quite a bit by neighbourhood, but the city-wide average is well above the national mean.

Average indoor level: ~160 Bq/m³

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New Brunswick

New Brunswick has higher radon than most Canadians would expect, driven by granitic geology in parts of the province. The survey found about 27% of homes above 200 Bq/m³, and some areas are much higher than the provincial average.

Homeowners in the central and northern parts of the province should treat testing as a priority.

Average indoor level: ~100–120 Bq/m³

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Alberta

Alberta has real regional variation. Southern Alberta, including Calgary and surrounding areas, tends to run higher. Northern Alberta is generally lower. About 18% of Alberta homes are above 200 Bq/m³, right at the national average, but that figure hides areas with quite high concentrations.

Calgary has been identified as one of the higher-risk major cities in Canada, and local awareness initiatives reflect that.

Average indoor level: ~80–100 Bq/m³

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Ontario

Ontario's average is close to the national mean, but the province is large. Northern Ontario, particularly over the Canadian Shield, tends to run higher. Southern Ontario, with its clay-heavy soils, is generally lower.

The survey found about 13% of Ontario homes above 200 Bq/m³. Below the national average, but given Ontario's population, that's still a lot of homes.

Average indoor level: ~60–80 Bq/m³

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British Columbia

BC's radon profile is complicated by its geography. Interior BC, particularly the Kootenay and Thompson-Okanagan regions, has elevated radon due to granitic bedrock. Coastal areas, including Metro Vancouver, tend to be lower.

The survey found about 34% of BC Interior homes above 200 Bq/m³, against about 1% on the coast and Vancouver Island. If you're in the BC Interior, your risk is meaningfully higher than the provincial average suggests.

Average indoor level: ~50–80 Bq/m³

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Quebec

Quebec sits close to the national average: the survey found about 19% of homes above 200 Bq/m³. Areas underlain by Canadian Shield rock, much of northern Quebec, have higher concentrations. Montreal and Quebec City sit on different geology and run a little lower, at about 16% and 18%.

Average indoor level: ~40–60 Bq/m³

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Atlantic Canada

Nova Scotia has elevated radon: the survey found about 37% of homes above 200 Bq/m³, with variation tied to the South Mountain Batholith granite formation running through the province. Prince Edward Island is generally lower due to its sedimentary geology. Newfoundland and Labrador has above-average risk driven by ancient Precambrian bedrock, particularly on the Avalon Peninsula.

The North

Data from Yukon, NWT, and Nunavut is less complete, but what exists suggests Yukon and parts of the NWT have elevated radon due to local geology. If you're in northern Canada, testing is recommended.

What this means for you

Provincial averages give you context, but they don't determine your home's radon level. Two houses on the same street can have very different readings depending on foundation type, ventilation, construction, and what's directly beneath them.

The only way to know your home's level is to test it. A long-term kit costs $30–$60 and takes 90 days. Given what we know about radon's health impact, it's worth doing regardless of where you live. If you're in Saskatchewan, Manitoba, Nova Scotia, New Brunswick, or parts of Alberta and BC, the case is especially strong.