Why is Air Quality Worse in the Winter?

Air quality refers to how clean or polluted the air is around us. Good air quality is vital for your general health and the survival of plants, animals, and other natural resources.

Many of us don’t think much about the air we inhale. The sad truth is that it’s more polluted than we think. These pollutants are oftentimes invisible. Sure, you can see smoke, smog, and dust, but there’s a lot more floating around than that.

Air pollution is a concern all year long. However, it worsens during the colder seasons. But why, exactly? In this blog, we’ll explore how the winter season affects air quality and how it can put you at a more significant health risk. Also, we’ll go over some suggestions to improve your air quality during winter.

baby playing in snow in winter

What Pollutes the Air We Breathe?

Air pollution is the presence of particles in the air that can be toxic or harmful to your health. There are various types of contaminants that lower the quality of indoor and outdoor air.

Pollutants that reduce outdoor air quality include fuel emissions, carbon monoxide, lead, dust, smoke, fire, ground-level ozone, and particulate matter. Indoor air pollutants include dust, volatile organic compounds (VOCs), asbestos, candles, stoves, mold, radon, tobacco smoke, and pet hair/dander

Being constantly exposed to polluted air poses significant risks to your health. Short-term effects of air pollution on your well-being include allergies, pneumonia, eye and nose irritation, skin problems, and headaches. Long-term effects can include lung cancer, heart disease, respiratory disease, and even death.

So, you can see why even if pollutants are naked to the human eye, they’re negatively impacting us every single day.

How Does Air Quality Change in the Winter?

Why exactly might air pollution be worse in winter, and how could it be contributing to your winter allergies?

1. Cold Air Traps More Pollutants

You’ve probably heard that warm air rises. This makes it easier for air currents to carry away pollutants. However, the situation is different in the colder seasons. 

With the drastic drop in temperatures, the air near the surface will be cooler than above. It’s also more dense than warmer air, meaning it has tinier spaces in between molecules. As a result, cold air sinks, and warm air rises. 

Essentially, a drop in the temperature leads to the cold air settling and forming a  blanket near the surface of the earth, forcing the warm air to rise to the top. The blanket of cold air traps pollutants with a higher density, making it harder for them to move and escape since cold air circulates less than warm air.

2. Pollutants Thrive on Dry Air

Another factor contributing to worsening air quality during winter is that air is less humid during this season. Since cold air does not hold as much moisture, the probability of rainfall is generally lower.

The problem here is that rain acts as a purifying agent by clearing pollutants in the air and stopping more contaminants from being released. Because there is less rainfall during winter, air purification is less likely to happen. Therefore, the dry air will hold more pollutants.

3. Our Winter Habits Encourage Indoor Pollution

Our behaviors during winter tend to contribute to an increase in air pollution. More often, our windows and doors remain closed, restricting ventilation. You might be using your fireplace more regularly, which can dry out the air and increase particulate matter. Plus, we’re spending more time in closer proximity to other people, which increases the spread of germs and bacteria.

winter living room air purifier

Additionally, think of the increase in fossil fuels. During the winter, homes need more heat and electricity. We might leave our cars running to help them defrost. While one person following these habits might not contribute all that much to air pollution, think of the collective ramifications of millions of people doing it.

How to Increase Your Indoor Air Quality During Winter

Now that you better understand how and why air quality can be worse in the winter, let’s talk about what you can do about it.

1. Use an Air Purifier

Air purifiers are one of the most effective ways of trapping contaminants and ensuring the air inside your house is clean. Be sure to use an air purifier with a medical-grade HEPA 13 filter, as it traps minute particles and invisible particles as small as 0.3 microns in size. 

2. Ensure Adequate Ventilation in Your House

Poor ventilation increases the pollution level in your home. First, check what the outdoor quality is like in your area using AirNow.gov. If it says that the air is cleaner, try opening your windows even for a few minutes at a time.

3. Maintain the Ideal Humidity

During the cold weather, the air tends to be drier in your home. Use a humidifier to keep your home at a comfortable level. This is usually somewhere between 40% and 50% humidity.

4. Keep Your Home Clean

Dust and vacuum your home once a week — more, if you have pets that shed. Disinfect high-touch areas, and change your bedding weekly. The dirtier your home gets, the worse the air quality will be.

The same applies to your furry friends. Groom and brush your pet regularly to reduce dander build-up and hair shedding. Otherwise, these particles will simply end up on the surfaces of your home.


dog playing in the snow in winter

Seasonal changes can have an impact on indoor and outdoor air quality. In winter, the temperature drops and density increases. Particles in the air get stuck there. Our personal habits at home don’t help. While it’s impossible to keep our breathing air perfectly pure, you can take steps to ensure it’s of a higher quality.

The Sans air purifier uses four layers of protection: a pre-filter, medical-grade HEPA 13 filter, activated carbon filter, and pulses of UV-C light. All work together to keep you and your family safe and healthy. Shop now!