Radon comes out of the ground, so where you live changes your odds. Some parts of Canada sit on geology that produces a lot of radon; others produce very little. But — and this is the part people miss — even in a low-radon region, individual homes test high. Geography sets the odds. Only a test sets your number.
Why some regions run higher
Radon is made when uranium in soil and rock breaks down. Areas with more uranium in the ground, plus the right soil to let the gas move up into homes, tend to see higher indoor radon. That's why radon is a regional story first. It follows the bedrock, not the city limits.
Health Canada has run cross-country surveys measuring radon in thousands of homes, which is how we know these regional patterns exist. But those surveys are about areas and averages — they can't tell you anything about your specific address. Keep that in mind as you read.
Here's where the risk tends to be highest in Canada, and where we run C-NRPP certified local teams.
The Prairies: Canada's radon belt
The Prairie provinces sit on flat, uranium-bearing ground, and they consistently show some of the highest radon levels in the country. If you own a home anywhere on the Prairies, the smart default is to assume you might be high until a test says otherwise. It's the one part of the country where testing should be automatic, not optional.
Saskatchewan
Saskatchewan has, by a clear margin, the highest measured home radon levels of any province in Canada. Testing here isn't optional. A large share of homes come back above the 200 Bq/m³ guideline. If you're in Regina or Saskatoon, assume you need to test. See the Regina radon map and the Saskatoon radon map for the general picture.
Manitoba
Manitoba is close behind, among the highest-radon provinces in Canada. Winnipeg homes frequently test above the guideline. Check the Winnipeg radon map for your area.
Alberta
Alberta is another higher-radon province, with many homes above the guideline across the south and centre. Both Calgary and Edmonton sit in higher-radon country. See the Calgary radon map and the Edmonton radon map.
Eastern Ontario and the Ottawa Valley
Radon isn't only a Prairie story. Eastern Ontario, including the Ottawa Valley, sits on Canadian Shield bedrock, a well-documented higher-radon area. Ottawa and its surrounding towns see a real share of homes above the guideline. The Ottawa radon map shows the general neighbourhood picture.
People are sometimes surprised that a city so far from the Prairies runs high, but it's the same physics: the bedrock here is rich in the kind of material that produces radon. Distance from Saskatchewan has nothing to do with it — the rock under your own foundation is what counts.
Interior British Columbia
Coastal BC is generally low, but the interior — the Okanagan, the Kootenays, and other valley regions — runs higher because of the local geology. If you're inland in BC rather than on the coast, radon is worth taking seriously.
Other regions worth a test
Radon doesn't stop at provincial borders. Parts of Quebec, pockets of Atlantic Canada, and scattered areas across northern and central Ontario also show high readings tied to local geology. The pattern is the same everywhere: uranium in the ground plus the right soil equals higher odds indoors. If you're outside the main hotspots but sitting on the wrong rock, you can still land above the guideline.
It's not just geology — your house matters too
Region sets the baseline, but the home itself decides how much radon actually gets in and stays. A few things push indoor levels up no matter where you live: a basement you spend real time in, cracks or gaps in the foundation, an open sump pit, and a tightly sealed, energy-efficient build that holds indoor air in. Our long, cold winters make it worse, because homes stay closed up and the furnace pulls soil gas in for months at a time.
This is why two identical-looking houses next door to each other can test far apart. One might have a sealed slab and good airflow; the other a cracked foundation and a busy finished basement. Same street, same geology, very different readings.
When should you test?
There's no bad time to test, but fall and winter are best, since sealed-up homes show radon closer to its peak. Many Canadians test in November, which is Radon Action Month, when public-health groups push awareness. If you've never tested, that's as good a reminder as any — but any month beats not testing at all. For the how-to, see our radon testing guide.
Where radon tends to be lower
Coastal areas generally run lower. Much of coastal British Columbia and parts of the Atlantic coast tend to see lower indoor radon than the Prairies. But “lower” doesn't mean “none.” Homes in low-radon regions still test high sometimes, which is why the rule below beats any map.
Regional maps show the odds for an area, not a reading for your home. Radon varies house to house because it depends on your exact soil, foundation, and how your home is sealed. Your neighbour's low result doesn't clear you. The only way to know your level is to test.
So what should you do?
Wherever you are, the steps are the same. Test your home — our radon testing guide walks you through it. Read your result against the guidelines in our safe radon levels guide. If it's high, a mitigation system fixes it; see the cost guide for what to budget.
Radon Removals runs C-NRPP certified crews across Canada's higher-radon regions — Ottawa, Calgary, Edmonton, Winnipeg, Regina, and Saskatoon. Pick your city below to see local pricing, your neighbourhood risk map, and a free assessment.