Constantly spotting wet streaks or droplets appearing on your windows? It’s not just irritating when you want to see outside. Regular condensation can actually be a sign that your windows need attention – or even lead to mold.

But condensation can fluctuate throughout the year, and you might notice that different seasons correspond to droplets forming on the inside or outside of your windows. Today, let’s break down why condensation occurs and explore some practical solutions to manage it in every season.

Why do my windows have condensation on the inside?

No matter the season, condensation forms when warm, humid air meets a cool surface – in this case, your window glass. The temperature difference causes the moisture from the air to condense into water droplets. Condensation on single-pane windows is more common overall compared to windows with multiple panes, as there’s just a single surface for air on either side to interact with.

In the fall and winter, interior window condensation is likely to occur. As the outdoor temperatures drop, the glass inside your home cools. When warm indoor air comes into contact with the chilly glass, condensation can form on the interior surface of your windows.

In the spring and summer, it’s the reverse; condensation on exterior windows pops up more often in these seasons. This happens when warm, humid outdoor air meets a cool window surface, typically caused by air conditioning inside the home.

While occasional condensation may not seem like a big deal, persistent moisture can be a serious red flag. It can indicate drafty windows that allow too much air exchange or excessively high humidity levels in your home. Left unchecked, this moisture can damage your windows and create a breeding ground for mold.

Managing condensation on interior windows in fall and winter

When chilly fall or winter weather blows into town, condensation inside windows becomes much more common. Here are a few effective ways to manage it:

1. Use a dehumidifier. Lowering your house’s indoor humidity can prevent excess moisture in your home from settling on windows. A portable dehumidifier works well for targeted areas, but a whole-house dehumidifier might be a better solution for widespread humidity issues. As a bonus, a dehumidifier could do wonders for making your home more comfortable.
2. Ventilate humid rooms. Rooms like bathrooms and kitchens generate a lot of moisture. Make sure to use exhaust fans when cooking, showering, or doing laundry to direct moist air outside.
3. Improve air circulation. Ceiling or portable fans can help circulate air throughout your home, preventing it from settling on cool window surfaces.
4. Upgrade to energy-efficient windows. Modern windows with proper seals and double- or triple-pane glass insulate your home better, minimizing the temperature difference that causes condensation. If your windows are old or drafty, replacing them can make a big difference in reducing condensation (and potentially reducing your monthly utility fees).

Solving exterior window condensation in spring and summer

In warmer months, you’ll be more likely to find condensation on the exterior of windows than on the inside. While it’s usually less concerning than interior condensation, it can still be an annoyance or lead to mold growth along your window’s exterior frame and sill. Here’s how to prevent it:

1. Seal your windows with weatherstripping. Adding weatherstripping around your windows creates a tighter seal, reducing drafts. This can help maintain consistent indoor temperatures, which minimizes the chance of exterior condensation forming. But keep in mind this may only be a temporary fix if your window is very drafty or if it’s a window you open often, like a sliding window.
2. Invest in energy-efficient windows. Upgrading to energy-efficient windows with insulated glass or low-emissivity (Low-E) coatings can reduce the amount of heat transfer, keeping hot outside air from encountering cool glass and reducing condensation.
3. Maintain a balanced indoor temperature. Avoid setting your air conditioning to a very low temperature, as this can create a more significant temperature difference between the glass and the outside air, leading to condensation.

What if you see condensation between window panes?

If you notice condensation between double panes or triple panes – in other words, inside your windows – it’s a sign of a bigger problem. This is due to seal failure, which allows air and moisture to infiltrate the space.

When this occurs, the insulating properties of your windows are compromised, which can lead to:

• Higher energy bills because your windows no longer regulate temperature effectively.
• An increased risk of window damage or mold growth in the affected area.

Once the seal is broken, the only effective solution is to repair or replace the window. If the damage is minor, a professional contractor may be able to reseal the window. However, in many cases, replacing the entire window is the better long-term option, particularly if the broken window is on the older side.

In any case, professional window contractors can assess the condition of your windows and recommend the best course of action. They can also handle the repair or replacement process, ensuring a durable and energy-efficient solution. can assess the condition of your windows and recommend the best course of action. They can also handle the repair or replacement process, ensuring a durable and energy-efficient solution.

Get tightly sealed windows for all-year comfort

Ultimately, the best long-term way to manage seasonal condensation is through installing energy-efficient windows. With several panes of glass and insulating gas between them, it’s much harder for hot or cold air to hit surfaces with extremely different temperatures. Add to that the potential energy savings and the interior comfort energy-efficient windows bring to your home, and they’re an overall excellent option for your next renovation.

Window World can help. Trust our contractors to recommend stellar replacements for your old windows and expertly install your new choices quickly and cost-effectively. Request a quote today, contact us to learn more, or visit your local showroom to get started!