Radon is one of those problems most people don’t think about until it’s already a concern.
It’s invisible, odorless, and easy to miss, yet it’s linked to thousands of lung cancer cases each year. Because there are no obvious signs, many homes go unchecked for years.
That’s what makes testing so important. But timing matters more than people realize.
In this blog, we’ll look at when you should test for radon and how to get results you can actually rely on.
Why Winter Is the Ideal Time for Testing
If you ask an expert for the best time to test for radon, they will almost always point to the winter months. This is due to a scientific phenomenon called the “stack effect.”
When it is cold outside, you crank up the heater and keep all your windows and doors tightly shut. The warm air inside the house rises and escapes through the roof or upper floors.
As that air leaves, it creates a vacuum in the lower levels of your home. This vacuum literally sucks radon gas out of the soil and through the cracks in your foundation.
The EPA recommends testing during “closed house conditions” for this very reason. You get a “worst-case scenario” reading when the house is sealed up tight.
If your levels are low in the dead of winter, you can usually feel confident about the rest of the year.
How the Weather Can Mess With Your Results
You might think any rainy day is a good day to stay inside and run a test. However, extreme weather can actually give you a false reading.
During a heavy rainstorm, the air pressure changes rapidly. High winds can also create pressure differences that pull more gas into the house than usual.
If you are doing a short-term test that only lasts two days, a big storm can skew the numbers.
This is where it gets tricky for homeowners who are in a rush.
You want to pick a window of time where the weather is relatively stable. Avoid starting a test right before a major front or a tropical storm moves through your area. Wait for a few days of calm, steady weather to get a result you can actually trust.
The Problem With Testing in the Summer
Summer is a popular time to buy and sell houses, but it is a tough time for radon gas testing.
In the warmer months, people tend to leave windows open or run attic fans. This additional ventilation dilutes radon levels in the living space. You might get a reading that looks perfectly safe in July.
However, that same house could have dangerous levels in January when everything is closed.
If you have to test in the summer, you must keep the windows shut for at least 12 hours before the test starts. You also have to keep them closed for the entire duration of the testing period.
This can be uncomfortable in the heat, but it is the only way to get a valid result.
The Truth Revealed from an Iowa Radon Study
Iowa is known for having some of the highest radon levels in the country.
A famous study conducted by the University of Iowa tracked the health of women exposed to radon in their homes. The researchers found a direct link between long-term exposure and increased cancer risks.
One of the big takeaways from the Iowa data was that levels fluctuate throughout the year. This is why many health experts suggest doing a long-term test if you have the time.
A long-term test stays in your home for 90 days to a full year. It averages out the highs of winter and the lows of summer. This gives you a much better picture of your actual risk over a lifetime.
The Impact of Radon on Buying or Selling a Home
In a real estate deal, you do not usually have a full year to wait for a test. Most home inspections happen within a 10-day window. This is when short-term radon gas testing becomes the standard.
Even if it is not the ideal season, a professional can still get an accurate “snapshot” of the home. They use calibrated machines that can detect if a window was opened or if the device was moved.
This prevents any “funny business” from sellers who might try to lower the results.
If you are the buyer, always ask for a test regardless of the time of year. If the levels come back high, you can ask the seller to install a mitigation system before you move in.
It is much easier to fix the problem before your furniture and family are inside.
Getting a Clear Picture of Your Home Safety
The best time to test for radon is now if you haven’t done it before. While winter provides the most dramatic results, knowing your levels at any time is better than guessing.
A house can have high radon even if the neighbor’s house tested low. It all depends on the soil directly under your specific foundation.
Testing is the only way to know if your “safe haven” is actually putting your health at risk. Once you have those results, you can take action and breathe easier.
Protecting your family from an invisible threat starts with a simple, well-timed test.
Professional Help for a Healthier Home
You deserve to know the air quality you are breathing in inside your home.
Ally Property Inspections is a professional home inspection company that finds the stuff others miss. We give you the clarity and detail regarding radon gas testing before you sign those closing papers or settle into a new place.
Our team stays focused on long-term property maintenance so your investment stays solid and your air stays clean. Give us a call today to set up a time for your professional radon check.
Let us help you move into your next chapter with zero doubts about your home safety.