Is There Moisture On The Inside Of Your Windows

As a homeowner in Bellingham, are you seeing humidity building up in side the windows of your home? If you have had this problem for long you may also be noticing mold build up around your windows. If you do not figure out what’s going on this can lead to respitory problems and damage do your home. We live in a humid climate and a homeowner should be aware of the needs of your home in this area!

Moisture build-up inside the windows of your home is a common problem, especially during the winter months. Let’s find out what causes moisture build-up inside windows and how you can prevent it.

Many modern thermostats have a built in humidity indicator. But if you do not that is no problem. Just watch your windows! If humidity starts building up it’s time for the prevention tips below.

How to Prevent Moisture On The Inside Of Your Windows

We won’t hold back the answer you are looking for. Here is how to address the situation and prevent moisture build-up inside windows.

  1. F you have a humidifier running inside a home for various reasons and this would be the first thing to address. If you check the humidity in your home you may already be over the recommended safe level. Check the chart below for tips!
  2. Run a dehumidifier instead: This is an easy fix if you are dealing with high humidity. It is important to remove excess moisture near the recommended levels in the chart below. Exceeding these recommendations can lead to problems.
  3. Proper ventilation is key to preventing moisture build-up inside your home. Make sure that your home has adequate ventilation, especially in areas like the kitchen and bathroom, where moisture is often produced. After a hot shower you can see the condensation building up on the mirror and this is how mouisture builds up on exterior windows as well. You can also install exhaust fans in these areas to help remove excess moisture from the air
  4. Insulate Your Windows: This can help prevent them from becoming too cold, which can reduce the likelihood of condensation forming. You can use weatherstripping or caulking to seal any gaps or cracks around your windows, which can also help reduce drafts and improve energy efficiency. Checking the caulking around your home is a maintenance procedure that should be done anyways.
  5. Open Windows: Opening your windows on occasion can help increase ventilation and reduce humidity levels in your home. If you see moisture just open them for a few minutes a day.
Outside TemperatureMaximum Relative Humidity
-20° F20%
-10° F25%
0° F30%
10° F35%
20° F40%
Research councils maximum relative humidity for interior air relative to exterior

What Causes Moisture Build-Up Inside Windows?

Moisture build-up inside windows is usually caused by condensation. Condensation occurs when warm, moist air comes into contact with a cold surface. When this happens, the moisture in the air condenses on the surface, forming droplets of water.

During the winter months, when temperatures outside are cold, and indoor heating is turned up, the temperature difference between the inside and outside of your home can cause condensation to form on your windows. This is true if the humidity level inside is higher than it should be. Also, if you have older windows with non modern insulation techniques, as they are more likely to be colder than the rest of your home. Modern windows will have at least a double pane and inside the 2 panes of glass is gas or air. This creates a barrier between the outside and inside pane of glass and serves as a form of insulation.

As already mentioned among the other causes of water on windows is high humidity levels in your home. Also cooking or showering without proper ventilation, or drying clothes indoors. These activities can release moisture into the air, which can then settle on your windows.

Sometimes a humidifier is run inside a home for various reasons and this would be the first thing to address. If you check the humidity in your home you may already be over the recommended safe level.

What are the Effects of Moisture Build-Up?

Moisture build-up inside windows may seem like a minor inconvenience, but if left unchecked, it can cause damage to your home. The moisture can seep into the window frames, causing them to rot and eventually leading to the need for costly repairs or replacement. Additionally, the moisture can cause mold and mildew to grow on your windows, which can be unsightly and potentially harmful to your health.

Excessive moisture will lead to build up of mold inside your wall cavity leading to damage!


Moisture build-up inside windows may seem like a minor problem, but it can have significant effects on the health and integrity of your home. By understanding the causes of moisture build-up and taking steps to prevent it, you can ensure that your home remains dry and comfortable throughout the year. Remember to keep your home well-ventilated, use a dehumidifier if necessary, insulate your windows, and open windows occasionally. By doing so, you can keep your windows clear and your home healthy for years to come.

We hope this helps clear up your humidity problem. A properly installed HVAC system by Bellingham HVAC will help control these issues but these tips will go a long way helping you maintain your current one

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