What Is Radon Gas? This Is Why You Should Test and Monitor Your Home.

Published on 12/21/2020 · Updated in 2026

What every homeowner should know about radon gas, daily fluctuations, and modern testing methods.

Radon detection with a radon detector. Maybe you've heard of how important it is to test your home for radon gas — but perhaps, like many of us, this is your first time looking into it.

When considering some of the facts about the threat radon gas poses to your health, the first question that comes to mind is why aren't more people talking about this?

• Radon gas kills 21,000+ people in the US alone.
• Amongst non-smokers, radon exposure is the leading cause of lung cancer.
• Children are 3x more sensitive to radon gas and health issues caused by it.
• Radon gas levels are highest during fall and winter when people are indoors.
• Radon levels can change hour to hour, not just seasonally — which is why HOW you test matters.

Radon gas has managed to seep into our homes, offices, schools, libraries, daycare centers, and other indoor spaces to the detriment of indoor air safety.

However, by educating yourself about radon gas and how to prevent, control, and mitigate it, you can safely avert the danger.

Radon Gas Explained

If you still remember the periodic table, then radon might sound familiar. That's because it is a chemical element with the 86th atomic number.

Radon gas naturally occurs in the environment as a product of uranium decay. If the very mention of the word uranium worries you, it should. Uranium is a radioactive element and is a key ingredient in the manufacture of nuclear bombs.

As you might imagine, any gas produced by the decay of something like uranium isn't going to be healthy for you. Descending from uranium explains some of why radon gas can be lethal, but it also contributes to other concerning characteristics.

Radon gas is:

• Odorless
• Colorless
• Tasteless
• Radioactive

These characteristics make radon gas impossible to detect without a special radon monitoring test kit. Testing for radon gas is critical since, owing to its radioactive nature, the mere presence of radon gas in your indoor environment is known to cause severe health issues after prolonged exposure.

How Radon Gas Enters Your Home

Across North America, people are unassumingly living with radon gas in their homes.

In the US, 1 in 15 homes contains dangerous radon gas levels, and in Canada, 7% of homes are thought to be in the danger zone. How does radon gas enter the home?

The uranium decay process that results in radon gas starts deep underground. Over time, radon gas travels up until it finally reaches the surface, which is often where homes are.

Home foundations and basements generally have different air pressure levels than the surrounding soil, which makes them act like vacuums for gases traveling through the soil.

Radon gas is drawn to homes on account of these forces, and can easily enter through cracks in basement flooring, foundations, pipes, and even water sources.

Once inside your home, radon gas will accumulate without proper ventilation in place. Radon concentration levels are compounded during the cold fall, winter, and spring months when homes are sealed for warmth.

Alarmingly, the winter months are also when people spend the most time indoors. School semesters are in full-swing, offices are busy with employees who vacationed during the summer, and cold weather keeps people inside the comfort of home.

Finally, radon gas levels fluctuate throughout the day as well, with radon test results typically showing higher levels in the morning and lower levels at night.

What many homeowners don’t realize is that radon levels don’t just vary by season — they can rise and fall multiple times within a single day due to weather pressure changes, HVAC cycles, and how a home is occupied. A single test result is only a snapshot, not the full picture.

Why “One-Time” Radon Tests Can Be Misleading

Traditional radon tests often provide a single average number over a short or fixed period of time. While these tests can be useful for initial screening, they can miss short-term spikes that contribute to long-term exposure.

Radon behaves dynamically; it's always changing. Levels respond to:

• Weather and barometric pressure

• Time of day

• Ventilation and HVAC usage

• Seasonal sealing of homes

This is why modern radon safety focuses on continuous monitoring, not just one-time testing.

How to Test Your Home for Radon Gas

Receiving an initial radon reading with a Best Radon Detector is helpful - but understanding how radon behaves in your home over time is what truly protects your family.

Modern radon monitors use rolling hourly data, meaning your radon level is continuously recalculated and updated in real time. This allows homeowners to see:

• Hourly changes

• Daily patterns

• Seasonal trends

• The impact of ventilation or mitigation

Ecosense radon monitors are designed for continuous, real-time monitoring, displaying visible radon fluctuations instead of a single static number. This approach gives homeowners clarity and confidence — especially in homes with children and pets, who are more sensitive to long-term exposure.

Want to see how radon changes in your home?

Continuous radon monitoring allows you to track real-time levels, spot patterns, and make informed decisions about your indoor air quality. 👉 Explore Ecosense Radon Monitors designed for real-time, rolling hourly data and long-term tracking of your home's radon levels.

Frequently Asked Questions About Radon Gas

Can radon levels change during the day?

Yes. Radon levels can fluctuate hour by hour due to changes in weather, barometric pressure, ventilation, and how a home is occupied. Many homes experience higher radon levels in the early morning and lower levels later in the day. Because of this natural variability, a single radon reading may not reflect true long-term exposure.

Is a short-term radon test enough to know if my home is safe?

Short-term radon tests can be helpful for initial screening, but they only capture a snapshot in time. Radon levels change daily and seasonally, so short-term tests may miss temporary spikes that still contribute to long-term health risk. Continuous monitoring provides a more complete picture of indoor radon exposure.

How often should radon be monitored in a home?

Health agencies recommend testing for radon every two years or after major home changes, such as renovations or HVAC updates. However, because radon levels fluctuate over time, ongoing monitoring is the most reliable way to understand long-term exposure and confirm that radon levels remain safe year-round.

What radon level is considered dangerous?

The U.S. Environmental Protection Agency (EPA) recommends taking action if radon levels reach 4.0 pCi/L or higher. There is no completely safe level of radon, and even lower concentrations may pose a risk over long-term exposure, especially for children and pets who are more sensitive to indoor air quality.

Why is continuous radon monitoring better than a single test?

Continuous radon monitoring shows how radon levels rise and fall in real time, rather than averaging results into one number. By using rolling hourly data, homeowners can see patterns, identify spikes, and understand how ventilation or mitigation impacts indoor radon levels. This approach supports more informed decisions about home safety.