Calgary Radon Map

The RadonTest.ca Calgary radon map — drawing on a 69,478-test national dataset of measured long-term results — puts Calgary at 15.5% of homes at or above Health Canada’s 200 Bq/m³ action guideline (about 1 in 6 homes), with a typical (geometric mean) level of 102.5 Bq/m³. Nationally the figure is 17.8%, and Alberta as a whole reads 17.5%. The highest reading in the Calgary metro area was 3,872 Bq/m³ — over 19× the guideline; across the wider Calgary census division (Division 6), which covers more ground, one home reached 7,199 Bq/m³. The ground beneath the area reads 1.44 ppm equivalent uranium on NRCan’s airborne survey.

See Calgary on the interactive map

Open the Canada Radon Map zoomed to Calgary → Search a postal code to find your immediate area.

The underlying survey data is public; the RadonTest.ca Canada Radon Map is the free tool that makes it searchable — by province, city and postal code, in English and French, no signup.

Calgary compared with its province and Canada

Nearby areas — where Calgary sits in context

Areas with few tests carry a wider margin of uncertainty — treat small-sample percentages as indicative rather than precise. A 0% reading means no home tested above 200 Bq/m³ among those measured there, not that the area is radon-free.

The same area at three different thresholds

Canada’s action guideline is 200 Bq/m³. The World Health Organization uses a stricter 100 Bq/m³ reference level, and the US EPA acts at 148 Bq/m³ (4 pCi/L). Measured against each, RadonTest.ca’s Calgary data reads:

No level of radon is completely risk-free — the risk rises with exposure, which is why the WHO line sits lower than Canada’s. Health Canada recommends acting within a year above 200 Bq/m³, sooner at higher levels.

Why this differs from older Health Canada figures

Health Canada’s 2009–11 national survey put Alberta at about 6.6% of homes at or above 200 Bq/m³, from 1,132 valid tests (2009–11 figures as re-tabulated by the 2024 survey team), with a typical level near 76 Bq/m³. This page uses the 2024 Cross-Canada Survey of Radon — 69,478 long-term tests, the largest residential radon dataset in Canada — which puts Alberta at 17.5% from 24,034 tests, typical level 104 Bq/m³.

Two things differ. First, the sampling: the 2009–11 survey recruited by random digit dialling across 121 health regions and deliberately over-sampled sparsely populated regions for geographic coverage, while the 2024 dataset aggregates long-term tests from homes whose occupants chose to test — which skews toward older housing, ground-contact basements and areas where radon is already a known concern. Second, the weighting: the 2009–11 figures quoted above are the raw, unweighted results. Because that survey deliberately over-sampled some regions, Health Canada also published population-weighted estimates, and its headline national result is 6.9%; the 11.3% raw figure comes from the 2024 survey team’s re-tabulation of the same dataset. None of these numbers is wrong — they answer different questions. For a population-representative estimate of Canadian housing, Health Canada’s weighted 6.9% is the right figure. For the largest body of actual measured results, use this page. Both are shown on the Canada Radon Map, and both can be switched between on the RadonTest.ca map. Full detail on methodology and sources.

Calgary: an average-looking city with an extreme tail

Calgary's 15.5% is close to the national figure, and the ground under the city reads 1.44 ppm equivalent uranium on NRCan's airborne survey — elevated, but not remarkable. What is remarkable is the tail. One Calgary-area home in the survey measured 3,872 Bq/m³, over nineteen times the guideline, and the wider Calgary census division (Division 6, 17,203 tests — a larger area than the metro) recorded 7,199 Bq/m³. Those are not typographical errors; they are what happens when a particular combination of soil, foundation crack and negative pressure lines up.

The commuter towns run hotter than the city. Okotoks reads 30.4%, Strathmore 28.3%, High River 25.3% and Canmore 13.9%. If you moved out of Calgary for more house, you likely moved into more radon.

Alberta has required a radon rough-in in new homes since 2015 — a capped pipe under the slab — which means mitigation in a post-2015 Calgary home is usually a matter of connecting a fan to existing pipe rather than coring the foundation. Alberta contributes 24,034 tests to this dataset, more than any other province, so Calgary's numbers rest on unusually solid ground.

The ground under Calgary, and why the tail is so long

NRCan's airborne survey reads 1.44 ppm equivalent uranium beneath the Calgary area — elevated on a national scale, though far from the highest in Canada. Geology alone would not predict a 3,872 Bq/m³ house. What produces readings like that is the stack effect in a tightly sealed home over permeable ground: warm air rises and escapes at the top of the building, the house pulls replacement air from the lowest available source, and if that source is soil gas through a foundation crack or an unsealed sump, radon comes with it.

Calgary's housing stock makes this worse than it sounds. A large share of the city was built during energy-code tightening cycles, producing well-sealed envelopes with full basements — good for heating bills, and exactly the conditions that concentrate soil gas.

Calgary versus the commuter belt

The pattern around Calgary is consistent and worth knowing before you buy: the further out you go, the higher the readings. Okotoks reads 30.4% and a typical 128.3 Bq/m³. Strathmore reads 28.3% and 124.0. High River reads 25.3% and 137.5 — a higher typical level than either. Against Calgary's 15.5% and 102.5, moving to the towns roughly doubles your odds.

Canmore, in the mountains west, reads 13.9% — slightly below the city. Red Deer, halfway to Edmonton, reads 15.1%. The high ground is south and east, on the plains, not in the Rockies.

A map cannot test your home

Every figure on the RadonTest.ca Calgary radon map is an area figure. Two identical houses on the same street in Calgary can test very differently, because radon depends on your foundation, your soil, your ventilation and how you live in the house. The map tells you the odds. Only a long-term test tells you your number.

Health Canada recommends a long-term test of at least 91 days, and you can start it any time of year. Ideally at least 91 of those days fall in the heating season (roughly October to April), and there is a simple rule for when they don’t: if your result comes back below 200 Bq/m³ on a mostly-summer test, Health Canada suggests re-testing next heating season, because a summer test can read low. If it comes back above 200, Health Canada says no re-test is needed — act on it. Find your Calgary home’s number — order a long-term kit →

What to do if your result is above 200 Bq/m³

Health Canada recommends taking corrective action within a year above 200 Bq/m³, and sooner the higher the reading. Most Canadian homes are fixed with sub-slab depressurisation — a pipe running from beneath the foundation slab to a fan that vents above the roofline, which, when properly installed, reduces levels by more than 80% in most homes (Health Canada); results vary by house. In Alberta homes built since November 2015, a capped radon rough-in should already be under the slab, which usually reduces the job to connecting a fan to pipe that is already there.

Work should be done by a professional certified through the Canadian National Radon Proficiency Program (C-NRPP), and the home should be re-tested afterwards to confirm the fix worked. You can also look up radon by address or postal code anywhere in Canada on the RadonTest.ca map.

Calgary radon map — questions

How high is radon in Calgary?

RadonTest.ca’s Calgary radon map puts about 15.5% of Calgary homes — 1 in 6 — tested at or above Health Canada’s 200 Bq/m³ guideline in the 2024 Cross-Canada Survey of Radon, with a typical level of 102.5 Bq/m³. Against the WHO’s 100 Bq/m³ reference level, 52.4% are over.

What is the highest radon reading recorded in Calgary?

On the RadonTest.ca map: 3,872 Bq/m³ in the Calgary metro area, in the 2024 Cross-Canada Survey dataset — over 19 times Health Canada’s guideline. Across the wider Calgary census division the highest was 7,199 Bq/m³. Readings like that are rare, and no map predicts them; only testing finds them.

Is there a free radon map for Calgary?

Yes. The RadonTest.ca Canada Radon Map is free and needs no signup, and covers Calgary at census-division and postal-area level.

Does the map show my street or postal code?

The RadonTest.ca map shows measured results for Calgary by census division and, for many postal areas, by postal prefix (FSA). It does not show individual addresses — no radon map anywhere does, because radon is measured house by house, not street by street.

Related

• Radon in Calgary: testing and mitigation
• Canada Radon Map
• Radon in Airdrie
• Radon in new-construction homes
• Methodology and data sources

Recommended citation: Calgary Radon Map, RadonTest.ca, 2026. Data: 2024 Cross-Canada Survey of Radon (v1.1 (CCSR.24.1.1), ISSN 2818-8195). https://radontest.ca/pages/calgary-radon-map Data licensed CC BY 4.0 — attribution required: “RadonTest.ca Canada Radon Map”.