What to Do With Foggy Windows

Oct 24, 2017

Have you ever noticed the windows to your house fogging up on cold nights? That fog is also called window condensation, and it’s caused when the cold temperatures outside meet the warm air inside your home, creating moisture. Window condensation is not, however, just some inevitable fact of cold weather. It speaks to a problem with your window, whether it’s a poor seal or glass that lets in too much cold air. Windows that fail to keep out the cold can cause a spike in your HVAC costs as well as moisture-created problems like mold and mildew.

If you notice window condensation on your windows, here are a few things you can do:

Consider the Time of Year

In the summer, you’re most likely to have exterior window condensation, which can actually be a good sign. Fog that appears on the outside of your windows occurs when the warmth of the outer glass meets with dropped temperatures on summer evenings. This means that the window hasn’t been conducting heat to the inside of the home, causing it to be stuffy and uncomfortable. Just clean off the windows or cool the glass for a cleaner look.

In the winter, however, the most common problem is interior window condensation, which means that the temperatures from outside are leaking through the glass into your home. This is a problem, one that will hike up your HVAC costs as you crank the heating to make your home more comfortable. The moisture can also cause mold or even structural problems to the window or the home surrounding it.

Cover the Glass

The quick fix to get rid of window condensation is to raise the temperature of the windows. This can be done with the use of blinds or drapes. The extra layer will help to keep the windows warm despite the cold outside, and block out the interference of the home’s interior temperature. This may even help keep cold air from circulating in your home during the winter, but it’s not the most effective fix and should not be a permanent fix by any means.


The window condensation may be caused by cracks in the window’s seal that let cold air in. If it’s just a problem of the seal, you can apply window sealant to the weak areas to strengthen the insulation of the window. Sometimes in the winter, a heavier seal is necessary to keep the cold air out, so you might want to invest in a vinyl clad seal, bulb seal, or weatherstrip tape to ensure proper insulation during the coldest months of the year.

Replace with an Energy-Efficient Window

Most often, however, it’s the glass that lets too much cold air into the home. For this reason, you may want to invest in a more energy efficient window replacement. Vinyl and fiberglass windows are known for their energy efficiency and durability. They can keep your home warm during the colder months and cool in the warmer months, thus eliminating the clash of temperatures that causes foggy windows. They’re also both low-maintenance options, so they’ll be easy to keep clean throughout the year.

Window replacement might seem like a hassle, but with the help of professionals with 40+ years of experience serving the area, it’s more manageable than you think. Call Johnson County Siding & Window Co. today at (913) 728 – 2878 or fill out our online form for a free estimate to find out how we can help you take care of your foggy window problem.


If you know you want to get your home exterior project done, but are feeling stress about paying for it all at once, we can help.

Our financing partner, GreenSky, has sensible payment plans that work for homeowners who prefer to pay in installments. You can also ask your JoCo Siding & Window Co. sales representative about the details!

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