Buy a $70 radon kit in June, set it on a basement shelf, mail it off in September, and you’ll get back a number you can’t use. If you’re wondering when to test for radon, the short answer on the Prairies is this fall: start a long-term test between October and January, so that at least 91 days of it run while the furnace does.
That timing isn’t fussiness. It’s what Health Canada’s own measurement guide asks for, and it’s the difference between a result you can act on and a result you have to repeat.
The short answer: when to test for radon on the Prairies
Health Canada says a long-term test should run for at least 3 months, “ideally during the fall or winter time.” Its measurement guide is more precise: “a minimum of 91 days of the test is during the heating season.” The Government of Manitoba puts it in local terms and suggests testing “ideally during the winter (ex: October to April).”
So the practical window looks like this:
- Start any time from early October to about mid-January.
- Leave the detector in place for at least 91 days. Three to 12 months is better, because the guideline is about your average over the year.
- Mail it to the lab once the time is up, and write down the start and end dates.
A kit started on 1 October reaches day 91 around the end of December. One started in mid-January still has room to finish by April. Starting in May is the one real mistake, unless you plan to leave the detector out for most of a year so it catches the next heating season.
Kits aren’t expensive. The provincial lung associations send buyers to HomeRadonTest.ca, which charges $70.00 per kit before tax, lab analysis and return shipping included. The Manitoba government says retail kits generally run between $50 and $100.
If you’d rather have a certified measurement professional place the test and handle the paperwork, call (204) 555-0173 or use the form. We don’t run tests ourselves. We put you in touch with a certified radon professional who does. There’s more on the options on our radon testing page.
Why the heating season is the best time to test for radon
Radon comes out of the soil and gets into a house through cracks in the slab, gaps around pipes, floor drains and sumps. Health Canada explains that the air pressure inside a home is usually lower than in the soil around the foundation, so soil gas gets drawn in.
A Prairie home spends half the year shut tight with the furnace running. That’s the house you actually live in from October to April, and it’s when a family’s basement gets the most use: the rec room, the kids’ bedrooms, the basement suite. A test taken with the windows open in July isn’t measuring those months. The heating-season rule makes sure the test sees them.
Some context before you worry. The unit is becquerels per cubic metre, written Bq/m3. (US material uses picocuries per litre: 37 Bq/m3 equals 1 pCi/L, so 200 Bq/m3 is about 5.4 pCi/L.) Canada’s guideline is 200 Bq/m3 as an average annual level in the part of the house where someone spends more than 4 hours a day.
That figure is a guideline, not a law. No Manitoba or Saskatchewan law requires a homeowner to test or to fix anything. Health Canada still says every home should be tested. It calls radon the number one cause of lung cancer in non-smokers and estimates it’s behind more than 3,000 lung cancer deaths in Canada each year. That’s reason enough to get a proper number, and no reason to panic before you have one.
It’s also common here. For Saskatchewan and Manitoba, the 2024 Cross-Canada Survey on Radon found high levels in roughly 1 in 3 of the homes that were tested. Health Canada is blunt that “there are no areas of Canada that are ‘radon-free’.”
What a proper test looks like (and what doesn’t count)
Timing is half of it. Placement is the other half. Health Canada’s Guide for radon measurements in homes asks for:
- The lowest lived-in level of the home. That means the finished basement if someone uses it, not the furnace room, the laundry room, a crawl space or an unfinished storage area.
- The breathing zone: at least 30 cm above the floor and at least 30 cm from walls and ceilings.
- Nowhere near sump holes, vents, windows, doors, heat sources or direct sun.
What doesn’t count is anything short. Health Canada says short-term measurements “are not appropriate for informing mitigation decisions,” and a test that runs under 91 days should be repeated. That covers the free library monitors, too. They’re good screening tools and worth borrowing, but they don’t give you the annual average the guideline is built on. We compare the two in long-term vs short-term radon tests.
The library programmes follow the heating season as well:
- Winnipeg Public Library lends screening kits at every branch from 1 November to 30 April, on a three-week loan with no renewals.
- Regina Public Library has 30 kits, lent for three weeks with no renewals, to Regina residents.
- Moose Jaw Public Library lends them from 1 October to 1 April, free with a card.
- Saskatoon libraries have lent detectors too. Check with your branch for current terms.
The library borrowing guide goes through each one.
Three Prairie homes, three timing decisions
These are illustrations, not real clients.
A 1962 bungalow in St. Vital with a finished basement bedroom. The owners heard a radio piece about radon in May and ordered a $70 long-term kit straight away. Their question was whether to open it now. If the detector sits out from May to August, none of its 91 days lands in the heating season, and Health Canada would have them test again. The better move is to keep the kit sealed until October and set it up in the basement bedroom, since that’s where someone sleeps eight hours a night. It comes back to the lab around New Year’s. The kit costs the same either way. Waiting four months just means they only pay for it once.
A library monitor reading 480 Bq/m3 in a Regina rec room. Three weeks in January, and the number is well over 200. That’s worth taking seriously. Of the Regina homes tested in the 2024 Cross-Canada survey, 46.6% were at or above 200, so a high screening result there isn’t unusual. But it’s still a screening result. Starting a long-term kit in the same room right away, in late January, still fits 91 days in by the end of April, and the owner then has a number a mitigation professional can quote against. For scale, a Regina installer advertises systems at $2,500 to $3,500, and more for crawl spaces or multiple suction points. Waiting three months for a proper result costs nothing and makes that quote more useful.
A Saskatoon two-storey bought in July, with radon written into the offer. A sale rarely lines up with the heating season. C-NRPP’s advice for a real-estate deal is that a short-term screening “could be conducted to provide some insight,” then a long-term test after you move in. Of the Saskatoon homes tested in the 2024 survey, 17.8% were at or above 200, roughly 1 in 6. So the buyers here did the short screening before closing, and planned a $70 long-term kit for October. Whether to ask for a holdback or a price change on a screening number is a question for your realtor or lawyer, not for us. There’s more in radon testing when you buy or sell a home.
When to test for radon again
One good test isn’t forever. Health Canada and C-NRPP list several points where you should test again, and most of them should also be timed for the heating season.
| Situation | When to test | Type of test | Cost figure we have |
|---|---|---|---|
| Never tested | Start October to mid-January so 91+ days fall in the heating season | Long-term kit or approved digital monitor, 3 to 12 months | $70.00 per kit before tax (HomeRadonTest.ca) |
| Borrowed a library monitor | During the loan season (Winnipeg 1 Nov to 30 Apr, Moose Jaw 1 Oct to 1 Apr) | Screening only | Free with a library card |
| Tested under 200 | Within 5 years, or after major renovations (C-NRPP) | Long-term | $70.00 per kit before tax |
| Finished the basement or added a suite | Next heating season, since that floor is now the lowest lived-in level | Long-term | $70.00 per kit before tax |
| After an energy retrofit | Next heating season | Long-term | $70.00 per kit before tax |
| New home | First heating season after you move in, and again 2 years after the year it was built | Long-term | $70.00 per kit before tax |
| Mitigation system just switched on | Right away, then again in the first heating season | Short-term by a certified professional, then long-term | Quoted by the professional |
| Existing system | Every 5 years | Long-term | $70.00 per kit before tax |
The new-home line matters more than people expect. Manitoba adopted a radon rough-in requirement on 1 April 2011, and the 2020 codes in force in both provinces since 1 January 2024 require one: commonly a 100 mm pipe below the basement floor, sealed and labelled. But the code is plain that “the depressurization rough-in does not actively reduce radon levels.” A 2015 Winnipeg build with a capped pipe in the utility room is an unknown until someone tests it. If the result is high, a fan has to be added to make the rough-in do anything, and a 2013 Winnipeg study found “almost half are in inaccessible locations.” We cover it in radon rough-ins in new homes.
What to do once the result is in
Below 200 Bq/m3, Health Canada says the risk is small, but “there is no level that is considered risk free.” It’s your call. C-NRPP’s advice is to retest within five years, or after major renovations.
Above 200, Health Canada recommends fixing it within 1 year, and sooner the higher the number. The usual fix is sub-slab depressurization: a pipe through the basement floor, a fan that runs all the time, and a discharge outside. Health Canada recommends a C-NRPP certified mitigation professional. Every house is different. Slab condition, a sump pit, a crawl space or a finished basement can all change the job and the price. The mitigation page explains how the systems work.
On price, Winnipeg installers advertise systems from about $1,500 to $3,000, and a Regina installer quotes $2,500 to $3,500. Nobody has published a Saskatoon price that we could find. Those are what individual contractors advertise, not a quote for your house.
Timing matters at this stage too:
- One Winnipeg installer adds 20% for off-season work, which it defines as 30 November to 20 May. If your result is only a little over 200, the one-year window gives you room to book around that. If it’s far over, don’t wait on a discount.
- After the install, Health Canada wants a short-term test by a certified professional once the system is on, then a long-term test during the first heating season, in the same spot as your original test. A system installed in June gets its real check the following winter.
- The Canadian Lung Association’s Lungs Matter funding, run in Manitoba by the Manitoba Lung Association, pays up to $1,500 for households below the provincial median income, and funding is limited. It requires a long-term C-NRPP approved test of 90+ days showing a result over 200, plus a C-NRPP quote. Digital monitors don’t qualify, and it doesn’t cover work already done. A fall test gets you the paperwork by winter.
- The Manitoba Hydro Home Energy Efficiency Loan covers radon mitigation up to $5,000 over 5 years at 6.2% (O.A.C.), with a C-NRPP certified contractor.
- In Saskatchewan, Lung Saskatchewan has offered reimbursement in the past, so check its site. Lung Saskatchewan also says radon mitigation counts as an eligible expense for the provincial Home Renovation Tax Credit. Confirm that with CRA before you count on it.
If your long-term result is over 200 and you want a quote from a certified radon professional, call (204) 555-0173 or send us the form. We’ll put you in touch with an independent C-NRPP certified mitigation professional who serves your area. You can check anyone’s certification yourself in the C-NRPP directory.
Frequently Asked Questions
What is the best month to start a radon test?
October is ideal on the Prairies, and anything up to about mid-January works. Health Canada wants at least 91 days of the test to fall in the heating season, and the Manitoba government suggests testing between October and April. A test started in spring or summer usually has to be repeated.
Can I test for radon in summer?
You can, but a short summer test won’t tell you your annual average, and a 91-day test that runs entirely outside the heating season doesn’t meet Health Canada’s method. If you’re selling or buying in summer, a short screening can give you some insight. Follow it with a long-term test once the furnace is running.
How long should a radon test run?
At least 91 days, and 3 to 12 months is better. Anything shorter is screening, and Health Canada recommends a new test if a result came from under 91 days. The library monitors, loaned for about three weeks, fall in the screening group.
Do I need to test again after a radon system is installed?
Yes. Health Canada wants a short-term test by a certified professional once the system is on, then a long-term test during the first heating season, in the same place as your original test. After that, retest every five years.