Guide to Window Condensation

Window condensation is a common issue many homeowners face. Condensation typically occurs during the winter months when there is warm air inside, but cold temperatures outside, or in the summer months when humidity is at its highest.

Condensation can appear on the interior and exterior of your windows, but it is preventable. In this guide we will discuss what window condensation is, what causes it, if homeowners should be worried about it, and how to prevent it.

What Is Window Condensation?

Window condensation happens when extreme temperatures are on either side of the window glass. When the outside air is cold during the winter but warm and humid inside, window condensation will appear on the interior of your windows. On the contrary, it will show up on the exterior windows during the summer if your windows are colder than the dew outside.

Should You Be Worried About Window Condensation?

If you see some condensation on your windows, it’s not always a bad thing. Moisture buildup is normal, but excessive moisture buildup can lead to larger issues within the home. If window condensation keeps coming back, it could lead to water damage, cause damage to the home’s insulation, mold, or mildew.

How to Prevent Window Condensation

During the winter, prevent interior window condensation by lowering the humidity levels in your home. To do this, allow for optimal air circulation and ventilation, use kitchen and bathroom fans when cooking and showering, open the windows for a short period of time during the day, and open drapes and blinds so the heat isn’t trapped inside.

During the summer, preventing exterior window condensation is easier because it’s much more common and doesn’t necessarily mean anything is wrong with your windows. This is a seasonal issue that doesn’t require as much preventative action. Waiting for the sun to come out to dry up all the extra moisture should suffice.

Window Condensation: Key Takeaways

Window condensation isn’t always a sign there’s an issue with your windows, but it can be a warning sign that there is too much humidity inside your home. Take the necessary steps to reduce indoor humidity so it doesn’t lead to larger issues like mold, mildew, and water damage.


Reflect Window & Door offers window services for both residential homes as well as businesses and other commercial applications. Our team of expert window contractors is available for almost any project, regardless of how small or large it may be.

We service all types and sizes of windows, including vinyl windows, aluminum windows, wood windows, and others. We can work with casement windows, awning windows, sliding windows, bay windows, picture windows, skylights, and more. Schedule a consultation now!