Should I Open My Windows at Night?

Sunny days and warm temperatures have your home heating up throughout the day. To help relieve that heat, many homeowners recommend opening your windows at night. But just as many seem to think that doing so carries more risks than benefits.

So, should you open your windows at night?

The answer, as you can imagine, is much more complicated than a simple yes or no. In this article, we’ll look at all the reasons you may want to consider opening your windows at night, as well as some excellent reasons you may want to keep them shut.

A residential home with the windows open

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Things to Consider Before Opening Your Windows at Night

There are many benefits to keeping your windows open during the night. But whether or not these benefits pertain to you really depends on your climate and the current weather.


a thermostat displaying the thermostat at night

Nighttime generally brings cooler temperatures and some much-needed relief from the heat of the day. But that doesn’t always mean the air outside will be cooler than the air in your home.

If you have had your AC on all day or have a well-insulated house that stays naturally cool, the temperature inside your home may very well be less than the temperature outside. If that’s the case, then leaving your windows closed overnight may actually help keep your house cooler.

But, in many cases, the temperature outside is going to be cooler overnight than the temperature inside your home. If the overnight low is cooler than your home’s current temperature, turning off your AC and opening your windows before bed can help you save money and energy while keeping your house comfortably cool.


a person setting up a dehumidifier

The humidity levels inside and out are another thing to consider before opening your windows overnight.

In dry climates, the humidity level outside is almost always less than inside your home. If this is the case where you live, opening the windows at night can help keep your home more comfortable. Of course, if you live in an arid climate and rely on a humidifier to raise humidity levels inside, then you will want to keep the windows closed to retain humidity.

If you live in a humid climate, you will need to figure out if it is more humid outside or inside your home before you decide to open your windows. As we discussed in our article, Does Opening Windows Increase Humidity, figuring this out can be a bit complicated. In very humid climates, you are often better off keeping your windows closed and using a dehumidifier to make your home more comfortable.

Fresh Air

A bedroom with open windows

Even if there is little difference between the temperature and humidity level inside and out, it may be worth sleeping with the windows open just for the fresh air.

With the windows closed, the air inside your home can get stagnant and stinky. Even with your HVAC fan running, indoor pollutants from carpeting, mattresses, paint, and cooking can build up to unhealthy levels. Opening a window can help diffuse these toxins and allow you to breathe easier.

If you sleep with your door closed, you also have to worry about carbon dioxide buildup. While it would take days of being locked in your room for these levels to become dangerous, it is still better for your health to breathe fresh air than air that is heavy with carbon dioxide.

Why You May Want to Keep Your Windows Closed at Night

a woman closing the windows at night

There are some circumstances in which the risks of opening windows at night are more significant than the benefits of fresh, cool air. You should consider the crime rate of your neighborhood, your sensitivity to allergies, and outdoor pollutants before opening your windows, day or night.


If crime is high in your neighborhood, you should think twice about opening your windows at night. You should even reinforce the windows by using dowels or window slide locks to keep people from getting inside.

Related article: 10 Burglar Deterrent Gadgets To Keep Your Home Safe


If you are allergic to pollen, cotton, or other outdoor allergens, you should keep your windows shut. You can check your local air quality report to see how high allergen levels are in your area. Save your window opening nights when allergens you are sensitive to are at their lowest.


Sadly, in many areas of the globe, the air inside your home is likely to be less polluted than the air outdoors, mainly if you use an air purifier. And, if you live in a populated city, in an area with inversion, or near factories or refineries, you are better off keeping your windows closed most of the time.

Even in areas with clean air, you should check the air quality report before opening your windows. Forest fires, weather changes, and other local conditions can cause pollutants to accumulate. In these cases, you are better off leaving the windows closed and the AC on.

Bottom Line: Should Windows Be Opened at Night?

When it comes to opening your windows at night or keeping them closed, it depends on your specific situation. 

If the air is cooler, cleaner, and more comfortable outside, then opening your windows at night can have a lot of benefits. Just be sure you are taking the necessary safety precautions.

On the other hand, if it is too hot, humid, polluted, or unsafe, then keeping your windows closed is the better option. If you are sensitive to allergens and they are abundant outdoors, it is also best to keep the windows closed, at least for the time being.

Have questions about keeping your windows open at night? Comment below!

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Aaron Green
Aaron is a qualified electronics technician with over 20 years of experience. He has an avid interest in all things tech-based and loves to keep up with the latest products and inventions.

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