How Winter Weather Affects IAQ

In western Washington, winter air hangs heavy. Rain falls, windows stay closed, and heaters hum around the clock. It keeps the cold out, but it also keeps everything else in. 

The same air keeps moving through your house repeatedly, carrying dust, pet hair, and moisture with it. That’s why indoor air often feels stale once winter settles in.

Why Winter Makes Indoor Air Quality Worse

Once the weather turns cold, most homes stay sealed tight. Fresh air stops drifting in, and the air inside keeps recirculating through the ducts. Each pass stirs up particles and spreads them through every room. You start to notice dry throats, static, or a faint dusty smell that never really goes away.

In Washington, outdoor air is damp while indoor air gets too dry from constant heating. That mix can throw humidity off balance. One week, you’ll see condensation on the windows; the next, your skin feels tight and dry. That push-and-pull is what makes the air feel uncomfortable in winter.

A few things usually make it worse:

• Closed windows and doors that limit ventilation.
• Dry indoor air irritates sinuses and skin.
• Furnaces that move old dust through the system.
• Fireplaces or gas appliances that release extra particles.

Even if your home feels warm and cozy, the air itself can still be crowded with what you can’t see.

What Causes Poor IAQ

Every house in western Washington has its own set of air problems. Older homes may have ducts that leak or insulation that traps moisture behind walls. Newer homes, built to save energy, can be sealed so tightly that air has no way to escape. Either way, stale air builds up fast.

Common causes include:

• Dust and dander that collect on carpets and furniture.
• Combustion gases from stoves, furnaces, or fireplaces.
• Cleaning sprays and scented candles that release VOCs.
• Mold spores that grow in damp corners and crawl spaces.

If you’ve noticed your home smells different in winter or feels heavier after weeks of rain, your indoor air quality is likely dropping. An air quality professional can test what’s circulating and suggest simple changes such as better filtration or controlled ventilation.

How Bad Air Quality Can Affect Your Health

Bad air inside shows up in small ways first. Maybe your nose feels stuffy in the morning, or you cough a little more than usual. Some people get headaches that fade once they step outside. Others feel tired or notice itchy eyes they can’t explain.

People with allergies or asthma feel it sooner. When the same air keeps cycling through, it carries irritants that never get filtered out. In the damp parts of western Washington, trapped humidity can also encourage mold growth, which makes breathing even harder.

Clean air matters for comfort, but it also matters for health. It helps you sleep better, breathe easier, and stay more comfortable through a long stretch of indoor weather.

Tips for Improving Indoor Air Quality in Winter

You don’t need a major remodel to make your air cleaner. A few steady habits help a lot.

• Replace or wash HVAC filters often during the heating season.
• Upgrade to higher-efficiency filtration that traps fine dust and pollen.
• Add an air scrubber to reduce odors, smoke, and bacteria.
• Schedule a duct cleaning if it has been several years.
• Use a whole-home humidifier to keep moisture balanced.
• Open a window for ten minutes on mild afternoons to let fresh air move through.

Winter air in Washington can be unpredictable, damp one day and dry the next. Regular maintenance with an air quality professional keeps your system ready for both.

Keep Your Home’s Air Clean and Comfortable This Winter

When it’s gray and wet outside, most of us think only about keeping the heat in. But the air you breathe indoors is just as important. 

Dry heat, low airflow, and closed windows can leave the house feeling stale. A few simple steps, like using the right filter and checking your ventilation, can make a big difference.

Black Hills helps Washington homeowners create cleaner, healthier spaces year-round. Our air quality experts know how local weather affects your home’s comfort systems and the air that moves through them. This winter, we’ll help you keep the heat in, the air fresh, and your family breathing easy.