Radon in Winnipeg: Levels, Risk & What Homeowners Should Do

Manitoba has the second-highest radon levels of any province in Canada. About 19% of Manitoba homes exceed Health Canada's action level of 200 Bq/m³, compared to roughly 7% nationally. In some communities across the province, that number climbs above 44%. If you own a home in Winnipeg and haven't tested, it's worth understanding why this province is different.

Winnipeg radon levels by the numbers

Studies of the Winnipeg area have found an average indoor radon concentration of around 118 Bq/m³ in detached homes, with basement readings typically running closer to 200 Bq/m³. Both figures are well above the national average of approximately 25 Bq/m³.

Manitoba Health estimates that about 1 in 5 Manitobans live in homes above the 200 Bq/m³ guideline. Nationally, it's 1 in 14.

For a major Canadian city, that gap is significant. And it's not evenly distributed across the province — in certain communities, surveys have found over 90% of homes above the guideline. Winnipeg's numbers sit somewhere in the middle of that range, but the city's geology means the baseline risk is higher than in most Canadian urban centres.

Why Winnipeg has elevated radon

The explanation comes down to what was here before the city.

Winnipeg sits on the former bed of Lake Agassiz, a massive glacial lake that covered much of Manitoba thousands of years ago. When the lake receded, it left behind deep deposits of glaciolacustrine clay and glacial till, overlain by a complex mix of sands, silts, and clays carried by the Red River.

This soil composition affects radon in two ways. First, the underlying geology contains elevated concentrations of uranium and radium that produce radon gas continuously. Second, the dense clay layers can trap and channel soil gas, concentrating it in ways that less compact soils would not.

Cold climate makes it worse. Winnipeg winters are long and harsh. Homes are sealed from around October through April, sometimes longer. During those months radon that enters a home has few ways out, so concentrations build up steadily. A home that might test modestly in July can read significantly higher by February.

What this means for your specific home

Provincial and city-wide averages set the context, but they don't tell you what's happening under your foundation. Two homes on the same Winnipeg street, with the same age and construction, can have readings that differ by a factor of five or more.

What matters most is the specific soil conditions beneath your house, how many gaps and cracks your foundation has, whether you have a sump pit or floor drains, and how well ventilated your basement is. Older Winnipeg homes with block or rubble foundations tend to have more natural entry points. Newer, tightly sealed homes can actually accumulate higher concentrations because there's nowhere for gas to escape once it gets in.

The only way to know your home's level is to test it.

How to test your Winnipeg home

Health Canada recommends a long-term alpha track test: a small device placed in the lowest livable area of your home for at least 91 days. The heating season, roughly October through April in Winnipeg, gives the most accurate result since your home is sealed and radon concentrations are at their peak.

Option 1: Mail-in long-term test kit (~$30 to $60)

The most reliable approach for making a mitigation decision. Place the device, leave it for 91 days or more, mail it to the lab. Results arrive within a couple of weeks. This is what Health Canada recommends before committing to any mitigation work.

The Manitoba Lung Association also offers test kits through a library lending program for residents who want to try before they buy.

Option 2: Electronic continuous monitor (~$160 to $350)

Gives you live readings and a running long-term average. C-NRPP approved models like the Airthings Corentium Home, Aranet RN+, or Ecosense RadonEye are accurate enough for mitigation decisions if you leave them in place for at least 90 days and read the long-term average rather than the real-time reading.

Place your test device in the lowest floor you use regularly, away from windows, vents, and exterior walls. Don't move it during the test.

More on choosing and placing your test: How to test your home for radon.

What to do with your result

Given Winnipeg's average basement reading of around 200 Bq/m³, a meaningful number of homeowners will test at or above the action level. If you do, the fix is sub-slab depressurization: a contractor drills through your foundation slab, installs PVC piping connected to a fan, and vents radon outside before it can enter your living space. A well-installed system reduces indoor radon by 80 to 99% and is typically done in one day.

For a plain-language breakdown of what your specific result means: How to interpret your radon test results.

Financial assistance: Manitoba has real programs

This is where Winnipeg homeowners have an advantage most Canadians don't. Manitoba has multiple programs that can offset mitigation costs.

Manitoba Hydro — Energy Finance Plan Manitoba Hydro offers financing for home energy improvements including radon mitigation. Payments can be spread over time, making a $2,500 system more manageable upfront. Confirm current terms directly with Manitoba Hydro.

Lungs Matter Lungs Matter is a Manitoba-based program that provides financial support specifically for home radon mitigation. It exists because of how seriously the province takes its radon problem. Check current eligibility and amounts at their website before budgeting.

Manitoba Lung Association Offers test kit access through a library lending program, so you can test without paying for a kit upfront.

As with all rebate programs: verify directly before counting on the money. Programs get paused, funding runs out, and eligibility requirements change. For a national overview of what's available: Government rebates for radon mitigation in Canada.

What mitigation costs in Winnipeg

Winnipeg sits close to the national average for mitigation costs, with a reasonably established contractor market given how long radon awareness has been part of the provincial conversation.

• Standard sub-slab depressurization: $1,500 to $3,000
• Complex configurations (block foundations, finished basements, multiple suction points): up to $4,000
• Post-mitigation re-test: $30 to $60, done 30 to 90 days after installation

Get quotes from at least two certified contractors. Any quote should include a post-installation test or clear guidance on how to arrange one. A system installed without verifying the result is incomplete work.

For a full breakdown of what drives cost: How much does radon testing and mitigation cost in Canada?

Radon in Winnipeg real estate

Manitoba's elevated radon profile means testing is increasingly showing up in local real estate transactions. Given the numbers, requesting a radon test as a condition of purchase is a reasonable step for any Winnipeg home, particularly ones with older foundations, block basements, or sump pits.

If you're buying, include a radon test in your inspection conditions. If the result is elevated, you can negotiate mitigation costs with the seller or factor them into your offer. If you're selling and you've already tested and mitigated, document it — it's a legitimate selling point in a province where buyers are becoming more radon-aware.

More on navigating radon in a transaction: Radon and real estate in Canada.

Find a certified radon professional in Winnipeg

Every contractor on RadonFinder.ca holds active C-NRPP certification, the national standard recognized by Health Canada. C-NRPP certified professionals have completed specific training in both radon measurement and mitigation.

Browse certified radon professionals serving Winnipeg

When you contact a contractor, ask whether they hold certification for both testing and mitigation (these are separate credentials), whether post-mitigation testing is included in the quote, and what warranty they offer on the installed system.

The bottom line

Manitoba consistently ranks as one of the highest-radon provinces in Canada, and Winnipeg reflects that. About 1 in 5 homes in the province exceeds Health Canada's action level. Testing is straightforward and costs $30 to $60. If your result is elevated, Manitoba has more financial assistance programs than almost any other province to help cover the fix.

• Browse DIY radon test kits and monitors
• Find a certified radon professional in Winnipeg
• See how Manitoba compares to other provinces