Manitoba Radon Map

The RadonTest.ca Manitoba radon map — built from 832 measured long-term tests in Manitoba, part of a 69,478-test national dataset — puts Manitoba at 43.6% of homes at or above Health Canada’s 200 Bq/m³ action guideline: the highest of any Canadian province. The typical (geometric mean) level is 181 Bq/m³ — more than double the national 84.7. Nationally the figure is 17.8%. The highest reading in Manitoba was 3,567 Bq/m³ — almost 18× the guideline, in the Central Manitoba–Interlake region. Against the WHO’s 100 Bq/m³ reference level, 73.6% of Manitoba homes are over the line.

See Manitoba on the interactive map

Open the Canada Radon Map zoomed to Manitoba → 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.

Manitoba radon levels by region

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.

Why Manitoba tops the country

Every region of Manitoba on the RadonTest.ca map reads above the national 17.8% — the only province where that is true. West-central Manitoba measures 74.6% of tested homes at or above the guideline, with a typical level of 325 Bq/m³ — a typical home there is over the guideline before the test even starts. Winnipeg, covered in detail on the Winnipeg radon map, reads 37.4% — more than double the national rate for a major city.

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 Manitoba data reads:

• 73.6% of homes at the WHO reference level (100 Bq/m³)
• 57% at the US EPA action level (148 Bq/m³)
• 43.6% at Health Canada’s guideline (200 Bq/m³)

No level of radon is completely risk-free — the risk rises with exposure. 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 Manitoba at about 23.7% of homes at or above 200 Bq/m³, from 1,183 valid tests (2009–11 figures as re-tabulated by the 2024 survey team), with a typical level near 107 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 Manitoba at 43.6% from 832 tests, typical level 181 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. Both are shown on the Canada Radon Map. Full detail on methodology and sources.

A map cannot test your home

Every figure on the RadonTest.ca Manitoba radon map is an area figure. Two identical houses on the same street 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. Test your Manitoba home — order a 91-day radon 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, typically cuts levels by 80–90% (Health Canada); results vary by house.

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.

Manitoba radon map — questions

Which province has the highest radon levels in Canada?

Manitoba — on the RadonTest.ca Canada Radon Map, 43.6% of Manitoba homes tested at or above Health Canada’s 200 Bq/m³ guideline in the 2024 Cross-Canada Survey of Radon, the highest provincial rate in the country, ahead of Nova Scotia (35.4%) and Saskatchewan (32.4%).

How high is radon in Manitoba?

The RadonTest.ca Manitoba radon map puts 43.6% of homes — nearly 1 in 2 — at or above 200 Bq/m³, with a typical level of 181 Bq/m³. Against the WHO’s 100 Bq/m³ reference level, 73.6% are over.

What is the highest radon reading recorded in Manitoba?

On the RadonTest.ca map: 3,567 Bq/m³ in the 2024 Cross-Canada Survey dataset, in the Central Manitoba–Interlake region — almost 18 times Health Canada’s guideline. Readings like that are rare, and no map predicts them; only testing finds them.

Is there a free radon map for Manitoba?

Yes. The RadonTest.ca Canada Radon Map is free and needs no signup, and covers Manitoba by region and postal area.

Related

• Radon in Manitoba: levels, risks and rules
• Radon in Winnipeg
• Radon in Brandon
• Canada Radon Map
• Methodology and data sources

Recommended citation: Manitoba 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/manitoba-radon-map Data licensed CC BY 4.0 — attribution required: “RadonTest.ca Canada Radon Map”.