Summary
As the weather cools and Ontario homes begin sealing up for fall, indoor radon levels can start to rise. Learn why autumn is an important season for radon testing and how to ensure your home remains safe before winter sets in.
How Seasonal Changes Affect Radon Levels
Radon levels are influenced by building conditions and seasonal weather patterns. In autumn, several factors combine to increase indoor radon concentrations:
- Reduced Ventilation: As temperatures drop, windows and doors are closed more often, limiting airflow and allowing radon to build up.
- Stack Effect: Warm indoor air rises and escapes through the roof, creating negative pressure that pulls radon from the soil into the basement or lower levels.
- Moisture in Soil: Autumn rainfall can trap radon underground, forcing more gas through foundation cracks and gaps.
These seasonal dynamics make fall a critical time to measure radon exposure indoors.
Why Test for Radon in Autumn?
Health Canada recommends testing for radon during the colder months when homes are more sealed up, giving the most accurate long-term results. Fall is the perfect time to begin a test because:
- You can capture data from both autumn and winter months in a single long-term test.
- Elevated levels detected now can be addressed before the peak of winter exposure.
- Testing early in the season gives homeowners time to plan and, if necessary, book mitigation services before contractors become busier in late winter and spring.
What to Do If Your Radon Levels Are High
If your fall test shows radon levels above 200 Bq/m³, mitigation should be scheduled. Common solutions include:
- Sub-slab depressurization systems that safely vent radon outdoors.
- Sealing cracks and sump pits to reduce entry points.
- HVAC adjustments to improve indoor air circulation.
Mitigation is typically completed in a single day by a C-NRPP-certified professional and reduces radon levels by over 90%.
Get Ahead of Winter, Protect Your Family
As fall sets in, we naturally focus on comfort—furnaces, insulation, and preparing for cold weather. But ensuring safe air quality is just as important. Testing for radon in autumn helps you take control of your family’s health before the highest-risk season arrives.
