Noticing condensation on your windows during Seattle’s rainy season? You’re not alone. Moisture often builds up on glass when warm, humid air inside your home touches a colder surface. Some condensation is normal, but too much can block your view, damage window frames, and lead to mold growth.
The good news is that there are several ways to stop window condensation before it becomes a bigger problem. Simple changes, like lowering humidity and improving airflow, can help keep your windows clear. However, if your windows keep fogging up, it may be a sign that they’re no longer working as well as they should.
Seattle gets about 156 rainy days each year, with 37 to 38 inches of rain. During December and January, humidity often reaches the high 80% range, while December nighttime temperatures drop to around 36°F. These cool, damp conditions make window condensation more common, especially in older Seattle homes with single-pane windows. When warm, moist indoor air from cooking, showering, or everyday activities touches the cold glass, water droplets can form on your windows.
Condensation forms when warm, moist air touches a surface that’s cold enough to turn water vapor into droplets. During colder months, your window glass may be much cooler than the air inside your home, making it easier for moisture to collect.
Where moisture appears on your windows can help you figure out what’s causing it and what you can do to fix the problem.
Condensation on the inside of your windows happens when warm, humid indoor air touches cold glass. It’s especially common during colder months when your heating system keeps your home warmer than the air outside.
You might notice water droplets along the bottom of your windows or spread across the glass.
Improving airflow, lowering indoor humidity, and keeping air moving around your windows can help reduce this moisture.
Condensation on the outside of your windows forms when warm, humid outdoor air touches glass that’s cooler than the surrounding air.
This often happens on cool mornings or when there’s a lot of moisture in the outdoor air. The water droplets usually disappear on their own as temperatures change throughout the day.
Outside condensation is usually harmless and doesn’t automatically mean your windows need to be replaced.
Double-pane windows have two layers of glass with a sealed space between them. When that seal breaks down, moisture can get inside and become trapped between the panes.
Unlike moisture on the surface of your windows, you can’t wipe away fog trapped between the glass panes or remove it by lowering your home’s humidity.
If moisture keeps collecting between the panes, it often means the window seal has failed. When this happens, you may want to consider replacing your windows to fix the problem.
Wondering how to stop window condensation in your Seattle home? The best place to start is with a few simple changes to your daily routine. These steps can help prevent moisture from building up on your windows when indoor humidity gets too high.
Too much moisture in your home’s air is one of the main reasons condensation forms on the inside of windows.
You can use a hygrometer, which is a small device that measures humidity, to check how much moisture is in your home’s air. If humidity stays too high, a dehumidifier can help remove some of that extra moisture.
Pay close attention to rooms where moisture builds up more easily, such as kitchens, bathrooms, and laundry rooms.
The right indoor humidity level depends on the weather outside and conditions inside your home. During colder weather, you may need to lower your home’s humidity to keep condensation from forming on the glass.
Good ventilation helps moist air leave your home before it has a chance to collect on your windows.
Turn on your bathroom exhaust fan during showers and leave it running afterward. Use your kitchen exhaust fan when cooking, especially when boiling water or preparing meals that create steam.
Make sure your clothes dryer vents outside your home. When the weather allows, opening your windows for a short time can also help fresh air move through your rooms.
These simple habits can help remove moisture from everyday activities while keeping the air inside your Seattle home fresher during the cooler months.
When air doesn’t move well around your windows, warm, humid air can stay near the cold glass and cause condensation.
Open your curtains and blinds during the day to let warm indoor air reach your windows. Try not to place large furniture directly in front of windows or block nearby heating vents.
You can also run your ceiling fans at a low speed to help move warm air around your rooms.
Better airflow can help reduce the amount of moisture that collects along the edges of your windows and around their frames.
Large differences in temperature can make window condensation easier to notice, especially when the glass gets much colder than the air inside your home.
Try to keep your home at a comfortable, steady temperature during Seattle’s colder months. Avoid letting certain rooms become unusually cold, especially at night when outdoor temperatures may drop.
Keeping your heating steady can help reduce cold spots near your windows and keep indoor surfaces warmer throughout the day.
However, heating your home won’t completely stop condensation if there’s still too much moisture in the indoor air.
When you notice condensation, use a soft, dry cloth to wipe moisture from the glass and windowsills before it has time to collect.
Check the nearby trim, window frames, and walls for signs of dampness or water damage. If these areas stay wet too often, the moisture can damage painted surfaces and create conditions where mold can grow.
Pay special attention to water collecting along the bottom edges of your window frames.
Removing moisture can help protect the materials around your windows. However, you’ll still need to find and fix what’s causing the condensation to keep coming back.
If your windows keep fogging up or moisture becomes trapped between the glass panes, it may be a sign that your windows aren’t working as well as they should.
Watch for these common warning signs:
Older single-pane windows may also collect more condensation on the inside because they don’t provide as much insulation as newer windows with multiple panes of glass.
Energy-efficient replacement windows can help keep the inside glass warmer and reduce certain types of condensation. However, even new windows can’t completely prevent moisture from forming when your home’s indoor humidity is too high.
At Renewal by Andersen, we offer custom-made replacement windows designed to help improve your home’s comfort, energy efficiency, and long-term performance.
Our Renewal by Andersen windows feature our exclusive Fibrex® composite material, which offers lasting strength, good insulation, and easy care with little maintenance.
You can also choose our High Performance™ Low-E4® SmartSun™ glass, which is designed to help reduce the amount of heat that passes through your windows.
Together, our energy-efficient frames and glass can help keep the inside of your windows warmer during cold weather. This can lower the chance of certain types of condensation forming on the glass.
Our Signature Service window replacement process includes a personal consultation, careful measurements, and custom-made windows designed to fit your home.
Our Certified Master Installers, who complete Andersen training, handle the installation. We also work with you to choose a replacement window solution that fits your home’s needs and your personal preferences.
We design our replacement windows to provide lasting performance using strong, durable materials that require little maintenance over time.
You can also learn about our Nation’s Best Warranty Coverage and review the specific warranty terms that apply to your window replacement project.
If your Seattle home’s windows are getting older, showing signs of damage, or no longer working properly, we’re here to help you explore replacement options that fit your needs.
Contact Renewal by Andersen today to schedule your free consultation, or call us at 833-201-6644 to get started.
