Radon Action Month: test your home this November

What is Radon Action Month?

November is Radon Action Month in Canada, a yearly campaign of Take Action on Radon, a national initiative funded by Health Canadasource. This page uses the month as a prompt for one thing: starting a long-term test.

The timing is practical. By November the heating season is under way across most of the country, which is when a long-term test should begin.

Why start a radon test at the beginning of the heating season?

Because a test started now spends its whole length in the conditions that matter. Health Canada recommends testing for at least three months, ideally between October and Aprilsource. At least 91 days of a test should fall in the heating season, when windows are closed and indoor radon tends to be highestsource.

November sits near the front of that window. A detector placed this month can run its full minimum and still finish with cold weather to spare, so there is room to extend the test if you choose. One placed at the tail end of winter has to be left out much longer before it has seen enough closed-window days.

There is also a plain human reason. Something that takes three months and needs no attention is easy to postpone for a year. Tying the start to a fixed point in the fall, such as the first furnace filter change of the season, gets it done.

Why does indoor radon rise when the house is closed up?

Because a heated house pulls air from the ground. Indoor air pressure is usually lower than the pressure in the soil, so soil gas is drawn in through cracks in foundation floors and walls, construction joints, gaps around pipes, floor drains and sumps, and the stack effect increases that entry in cold monthssource.

The stack effect is the same physics as a chimney. Warm air is lighter, rises through the house and escapes near the top. Air has to come in lower down to replace it, and the lowest openings a house has are in the basement floor. With the windows shut, less outdoor air mixes in to thin what arrives.

None of this can be seen or felt. Radon is a colourless, odourless, tasteless radioactive gas formed by the natural breakdown of uranium in soil and rocksource, and a basement with a high level seems no different from one with a low level.

Is it too late if the month is nearly over?

No. The calendar matters less than the furnace. Any start date from the first cold weeks of fall through midwinter leaves time for 91 days of heating season before spring. Health Canada's recommended test length is 3 to 12 months, with 91 days as the floorsource, so a test begun in December or January is as valid as one begun today.

What does not work is waiting for a perfect moment. A chinook week, a cold snap or a trip away are all part of an ordinary Calgary winter, and a three-month measurement is long enough to absorb them. Health Canada does not recommend testing for less than 91 dayssource, so the only real mistake is cutting the test short.

What should you do this month?

Start a long-term test. That is the whole assignment. Reading more about radon, comparing monitors and asking the neighbours what they found are all optional. Health Canada notes that levels differ from house to house, even between similar homes next door to each other, and that testing is the only way to be suresource.

Its recommendation is that every home be tested, wherever it is located and whatever the type of buildingsource. That covers the new build with a capped pipe in the basement floor, the older bungalow, the townhouse and the acreage. If you already tested, skip to the section on older results.

You can run the test yourself or have it run for you. Our step-by-step radon testing guide covers the first route, and a professionally placed long-term test covers the second. If you are not sure which suits your situation, the overview of radon testing options in Calgary compares them.

What does a simple plan look like?

A handful of short tasks spread over a winter, most of them a few minutes long. The table sets them out in order.

The plan has one long gap in the middle, and that is by design. Most of a radon test is waiting. Put the earliest end date in your calendar on the day you start, so the detector is not forgotten on its shelf until summer.

Where can you get a test kit in Calgary?

By mail, from the two programs described here. The prices below belong to those organizations, not to us. As of October 2026, the Evict Radon National Study sells an at-cost long-term kit for $53.99 with free shipping, on the condition that you consent to your result being shared with researchers in de-identified formsource. As of October 2026, Alberta Lung offers a 90-day radon test for $70.00 through HomeRadonTest.ca, a price that covers shipping both ways and laboratory analysissource.

As of October 2026, no free radon test kit program open to Calgary residents in general was listedsource. Giveaways appear and disappear from one season to the next, so look again each fall.

Our comparison of radon test kits for Calgary homes explains the types. If you prefer a device with a screen, remember that C-NRPP publishes which consumer-grade electronic radon monitors it has tested and approves, notes that they cannot be professionally calibrated, and advises leaving them in place for at least 3 monthssource.

Where should the detector go on day one?

In a room used for four hours a day or more on the lowest lived-in level, about 30 cm or more off the floor, away from walls, and not in a kitchen, bathroom or laundry room or near vents, heat sources, direct sun or electronicssource. A shelf in a basement bedroom or family room usually satisfies all of that at once.

Two mistakes are common in the first week. One is putting the detector in the furnace room because that feels like where radon would be. The other is moving it upstairs for a party and forgetting to bring it back. Pick the spot once, tell the household, and leave it.

What if you tested years ago?

Then this month may be for checking, not starting. Find the old report first, and note what kind of test it was and what has changed in the house since.

Some changes do reset the question. Health Canada recommends testing again after any renovation that affects the structure or ventilation of a home, after a mitigation system is installed, and every 5 years for homes with an active systemsource. A newly finished basement, new windows, a new furnace or an addition can all qualify. Separately, and as our own suggestion, a change in who uses the lowest level, such as a teenager moving into a basement bedroom, is a good prompt to test again.

If your old result came from a test of only a few days, treat it as a first look and run the long one now.

Why does this matter in Calgary in particular?

Because high results are common here and the heating season is long. The Cross-Canada Survey of Radon Exposure found about 1 in 6 houses in the Calgary area (15.5%) at or above 200 Bq/m³ and 36.9% between 100 and 199 Bq/m³, with an average of 102.5 Bq/m³source. Our page on why radon is common in Calgary houses goes through the research.

The reason to care is a long-term one. Health Canada lists a higher risk of lung cancer as the only known health effect of radon, and describes that risk as long-term, not immediate, and dependent on the level, the length of exposure and smokingsource. Nothing about a radon test is urgent in the sense of days. It is worth doing this season because each winter that passes untested is another winter of not knowing.

What happens when the result comes back?

You compare one number with one line. Canada's guideline is 200 Bq/m³, and Health Canada recommends corrective action when the annual average is above itsource. Above it, the recommendation is to mitigate within one year, sooner at higher levelssource.

Under the guideline, Health Canada's recommendation to act does not apply. Lower is better at every level, no level is considered risk-free, and the choice to reduce it further is yours. Above it, the next step is an assessment of the house, and radon mitigation in Calgary, from assessment to follow-up test describes what that involves. Health Canada reports that a system can usually be installed in less than a day and cuts radon by more than 80% in most homessource.

The checker for radon test results will read the number for you when it arrives, in Bq/m³ or pCi/L. Until then, the only job is the one at the top of this page.