When is the Best Time to Test Your Home for Radon
Posted in Radon Testing, on August 22, 2025
In this era of optimization, many homeowners want to select the perfect time for air quality testing to ensure the best results. While time and context can affect test results for general testing, today on the blog, the SafeAir team wants to focus on a specific type of assessment. Radon testing looks for the presence of radon gas, a colourless, odourless, invisible threat to you and your family’s health. Testing is the only way to know your home’s radon levels, and it is one test where timing often can and does play a critical role.
Why Radon Testing Matters
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First up — why have your home tested for radon gas? At SafeAir, we see three main reasons why testing is essential:
The Health Risks of Radon Exposure
It may not smell or damage the structure of your home, but radon is a radioactive gas that increases your likelihood of lung cancer — behind tobacco smoking, it’s the second leading cause of lung cancer in Canada! Without any symptoms or evidence, it’s tough to know if you’ve been exposed without radon testing.
Radon is a Common Yet Overlooked Threat
Radon naturally occurs across Ontario, but levels can vary widely between regions and even within neighbourhoods. Just because your neighbours aren’t affected doesn’t mean you are safe.
Testing Is the Only Way to Know
Unlike mold, which has a smell, or dust and dander, which cause allergic symptoms, radon gas causes no physical symptoms — until it’s too late. Having a professional radon test gives you accurate results and peace of mind.
Seasonal Factors That Affect Radon Levels
The seasons can affect your radon testing results — here’s how:
Winter
Homes are often the best time to test for radon gas, since windows and doors stay closed and there is less natural ventilation that may dilute results.
Spring and Fall
Transitional seasons are still good for testing, too. As the ground starts to freeze and thaw, radon levels will fluctuate.
Summer
Open windows and increased air circulation in the warmer months may sometimes lead to inaccurate, lower radon readings.
When Else Should You Test for Radon?
The time of year isn’t the only factor that you should consider when booking a radon test. At SafeAir, over a decade of experience testing homes across the GTA has given us valuable insight into the where, why, and when of radon fluctuations. If you are planning or have experienced any of the following situations, now is a good time to book your test:
- After a major renovation or HVAC change.
- Changes to the way air moves around your home (and therefore how radon collects and settles) can arise from major renos or even just a new furnace or a/c unit.
- After flooding or foundation work.
- Radon comes from deep within the earth and gets into the home through cracks or gaps in the foundation, especially if your home is older. If there has recently been a flood, the earth may have shifted and exposed cracks or caused gaps that may attract radon.
- Before buying or selling a home.
- Radon testing is a common and responsible thing to test for when moving. Providing recent test results signals to potential buyers that a property is safe and the homeowner is responsible.
Make Radon Testing a Part of Routine Home Health
It’s essential to conduct a reliable radon test. At SafeAir, we prefer 3-6 month-long testing periods, which help even out inconsistencies from seasonal shifts, weather events, or other changes to your household that may cause radon levels to fluctuate. Many municipalities offer quick snapshot testing, but in our experience, they lead to too many false positives or inaccurate results. For safe, trustworthy results, SafeAir recommends professional radon testing to ensure safety at home. To learn more about how we do air quality testing, how radon tests happen, or more about how radon gas gets in, please visit our blog or reach out to our team!