Why Winter is the Best Time to Test for Radon
Posted in Radon Testing, on November 26, 2025
Radon testing should be a part of every homeowner’s improvement plan. This safe and easy test is the best way to assess whether this dangerous, odourless gas is accumulating in your home. Radon tests can be performed as a stand-alone service or as part of general air quality testing in Toronto. SafeAir has been helping families identify radon gas at home for over 15 years, and we’ve found that the winter offers some unique advantages when it comes to testing.
Understanding Radon Behaviour in Homes
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Radon gas enters your home through cracks in the foundation, windows and doors, or through sump pumps or pipes. The negative pressure of your basement draws radon towards it as the gas travels through the earth’s surface, and once inside, it can collect in toxic levels.
Winter can cause radon to accumulate in greater concentrations because of changes to indoor air pressure, temperature, and lowered ventilation. Radon levels fluctuate all year round, which is why SafeAir prefers long-term testing over 3-6 months. This testing period can help us achieve more accurate readings by smoothing out these fluctuations caused by changing seasons.
Why Winter Provides the Most Accurate Readings
During the winter months, we tightly seal our homes to keep in warmth, but this has knock-on effects on our indoor air quality and radon levels. Closed windows and doors prevent natural air circulation and reduce ventilation that might otherwise help keep your radon levels within a safe range. Testing for radon gas or any indoor air quality pollution during the winter can thus tell us what the extremes are like — and perhaps help explain any unusual winter symptoms or allergies.
The Health Risks of Ignoring High Radon Levels
Radon gas is a natural part of the environment and usually dissipates harmlessly into the environment. But in our homes, accumulation above 200 Becquerels per cubic metre (200 Bq/m3) can significantly increase your long-term risk of lung cancer. Radon gas is radioactive, and when it decays within the lungs, it can cause scarring and cellular changes that have serious implications.
Steps to Take After A High Winter Test Result
If you’ve had a high radon test in the past, there’s no better time to retest your home than now! At SafeAir, we generally recommend the following steps:
- Retest (or test) to confirm radon levels.
- Work with a professional to identify radon entry points.
- Implement recommended radon mitigation strategies, like sub-slab depressurization.
Benefits of Professional Winter Radon Testing with SafeAir
SafeAir offers certified, accurate radon testing that can help you assess your home’s risks. Once your results have returned from the lab, we can help you interpret what they mean and give you expert guidance on choosing the best mitigation strategy based on your home, the severity of your results, and your budget. Testing for radon gas gives you peace of mind that your home is safe and that there are fewer risks to your health and safety.
Air quality testing in Toronto is especially effective during the winter months because of reduced ventilation and higher accumulation of indoor pollutants. Take action before substances like radon gas, mold, asbestos, dust, or other allergens begin to affect your family. Contact SafeAir for professional radon testing today.