Spring brings longer days, warmer weather and, of course, plenty of rain. While some homeowners welcome the arrival of April showers, many fail to realize that the wet weather can also bring something you can’t see, smell or taste: radon.
In this guide, we break down how the rainy season impacts radon levels — and what steps you can take to protect your family and your home.
Does Radon Rise or Fall? Understanding the Basics
Instead of thinking of radon in terms of rising and falling, it’s more accurate to think of it as shifting. Because radon is a gas, it’s always seeking a way to escape from the ground.
In certain environments, radon seeps through the ground, hits the open air and harmlessly drifts away into the atmosphere. When a building is present, the rules change. Gaps around the pipes or cracks in the concrete allow radon levels to increase and eventually accumulate in the base of a home, often residing in areas like basements or crawl spaces.
Changes in weather, air pressure and ground conditions all shape how much radon ends up inside a house at any given time, making regular testing crucial.
Are Radon Levels Higher When It Rains?
Many people think that the rain washes away airborne toxins. However, when it comes to radon, this isn’t the case. While a brief spring shower is unlikely to impact radon levels, heavy storms or several days of steady rainfall can increase readings.
Prolonged rainfall saturates the ground around a home, filling tiny air pockets in the soil with water. Normally, radon moves through these spaces and disperses in the air. However, when soil becomes waterlogged, radon’s escape route is blocked. Instead, it sneaks into buildings, taking the path of least resistance through the foundation. Saturated soil gives radon fewer places to go, increasing the likelihood of indoor entry during prolonged wet weather.
Fortunately, radon testing kits make it easy to check your home’s levels, which is especially useful during rainy seasons when fluctuations are more common.
Why Radon Can Increase in the Spring
Over time, radon levels change as your home interacts with its environment. Spring temperatures, soil conditions and weather can all result in swings in radon levels, even when you haven’t made any structural changes to your home.
Spring can increase radon levels due to:
- Heavy rainfall: Prolonged spring rain can saturate the ground, limiting radon’s natural escape route and instead pushing it into your home.
- Temperature swings: Warm indoor air escaping through your home’s roof or upper windows can create low-pressure zones near your foundation, drawing radon inside.
- Seasonal ventilation habits: Windows often remain closed during cold or rainy spring periods, allowing radon to slowly accumulate indoors.
- Soil conditions: Moist or compacted soil can trap radon, redirecting it toward basements or crawl spaces.
- Snow and ice thawing: If you live in an area with frequent snowfall, the thawing of ice and snow can lead to higher levels of released radon.
While winter is often considered the best time to test for radon due to increased levels, spring testing can also reveal elevated readings, particularly during the season’s infamous rainy periods. However, to fully protect yourself and your home, it’s best to test for radon at different times of the year.
Due to seasonal differences, you might get different radon numbers depending on when you test, leaving you wondering which figure is a true representation of your radon levels. In these cases, working with a professional who understands ANSI and AARST radon standards can help you get a more accurate reading.
Does Humidity Affect Radon Levels?
Yes, humidity can impact radon levels. While humidity itself doesn’t directly create radon, it can still influence how the gas behaves once it enters your home.
Moist air caused by rain can make indoor environments feel less well-ventilated, especially in basements or crawl spaces where airflow is already limited. These conditions can allow radon to linger.
Installing a dehumidifier isn’t enough to reduce radon — you need to address the root cause.
What You Can Do to Protect Your Home
According to recent research, 83.8 million U.S. residents are exposed to high — and potentially harmful — levels of radon. This gas is the leading cause of lung cancer among nonsmokers, making it crucial to limit radon exposure.
Thankfully, you can protect yourself by:
- Testing your home: Using an at-home testing kit makes it easy to get a grasp on your radon levels. If your figures exceed 4.0 pCi/L, it’s time to take action.
- Sealing cracks and gaps: Closing openings in foundations, pipes and basement floors can help limit how much radon enters your home, though it may not be a long-term fix.
- Improving ventilation: Increasing airflow in the lower levels of your home can sometimes help dilute radon levels. To get an accurate figure, test before and after making any ventilation changes.
- Installing a radon mitigation system: Adding a professional mitigation system can safely redirect radon away from your home for long-term protection, no matter the season.
- Timing your tests carefully: For certified radon measurements, avoid testing within 24 hours of heavy rain or a thunderstorm. Storms saturate the ground and temporarily spike indoor radon levels, which can skew your results. Wait at least two days after significant rainfall before conducting a certified test.
Every home is different, and radon doesn’t behave the same way in every space. That’s why consulting a qualified radon technician is the best course of action if you want peace of mind.
How SWAT Environmental Can Help
Although radon is invisible and odorless, you don’t need to leave it to chance. As the largest mitigation company in the U.S., SWAT Environmental has helped thousands of customers protect their homes.
Our goal? To make healthier homes and workplaces in neighborhoods everywhere. With nearly 40 years of experience, SWAT Environmental provides our qualified technicians with continuous training to stay ahead of evolving industry trends, ensuring you receive the most up-to-date protection.
We understand that your home is your personal sanctuary. That’s why our technicians treat your house as if it were their own, with care, respect and attention to detail throughout every step of the process. If something ever goes wrong, SWAT technicians pledge to come back and fix it, with ongoing support always just a phone call away.
Take Control of Your Radon Levels
Protect yourself from radon and order your at-home testing kit today, or reach out to our team to request a quote. You can also call us at 833-241-9158 for more information on radon mitigation.
