does outdoor humidity affect indoor humidity?

Humidity can be a real issue for some folks who have medical conditions or just don’t like that sticky feeling. It can make your home uncomfortable and can put a damper on all your energy. If you add high moisture levels to the humidity, it can make you feel downright miserable! 

People often wonder if the humidity outside is wreaking havoc on their indoor air, and the truth might be surprising to those of you who think it doesn’t have an impact. When the temp rises outside and the humidity skyrockets, chances are you’re going to feel it indoors as well. 

You can do some things to control the humidity in your house, and we’re going to cover that below. Keep reading to find out how you can be comfortable all year long in your home without worrying about the humidity.  

Does Outdoor Humidity Affect Indoor Humidity?

The humidity outside is always going to have an impact on the humidity in your home. The main reason is quite simple; you can’t keep the outside air from completely entering your home. There are many factors that contribute to this theory, such as:

  • Door Cracks
  • Window Gaps 
  • Lack of Insulation 
  • Opening and Closing of Doors 

But more importantly, high humidity levels combined with higher moisture levels can be cause for alarm. This dangerous cocktail can cause issues with the structure of your home, along with any surfaces that are subject to these conditions.  

It isn’t unusual for the excess moisture to damage your paint, wood, insulation, and sometimes it can even have a negative impact on your house’s siding. 

How Does Too Much Humidity Affect Your Health? 

If you’ve been worrying about your home and how the excess moisture caused by the humidity levels is damaging your property, you should be equally concerned about your health! 

There are plenty of allergens and pollutants that are affiliated with excessive moisture. People who suffer from allergies will be uncomfortable since contaminants like mildew, dust mites, and mold all harbor in areas that have higher humidity and moisture. 

If you or a loved one have been diagnosed with asthma or existing pulmonary ailments, you are also going to be affected by the humidity. Plus, all of these things can be a danger to your lungs, making breathing more difficult and leading to further health complications down the road. 

What Is The Ideal Humidity Level For Homes?

If you can keep your house’s humidity levels between 30% and 50%, you are already making excellent progress. This is the best range to provide comfort and works to improve the quality of air in your home. 

If you don’t have a proper device to give you accurate humidity and moisture readings in your home, now is a good time to invest in one. Once you know what the levels are in your house, you’ll be able to adjust it accordingly based on the tips below. 

Have a Question? Ask HVAC Technician

Click here to use the chatbox to speak with one of our technicians.
No in-home service calls. No appointments.

Keep in mind that the humidity levels will fluctuate in different areas of your home. For example, since heat rises, the humidity levels on a second or third floor will be much different than the ones you will find on the ground floor or even in a basement. 

It’s essential to monitor all the areas of your home and regularly check for any signs of mold or mildew. These are telltale signs that your home is experiencing humidity issues and needs to be addressed immediately. 

It is always best to keep your bedroom’s humidity levels in the 50% relative humidity range for better sleeping conditions and for reducing allergens and dust mites. In fact, the goal should be to maintain this level year round. 

Top 5 Tips To Control The Humidity Levels In Your Home 

Many people find it challenging to reduce or lower the humidity in their homes, which often is the culprit for spotting signs of mildew or mold building up in a particular area of your house. Below you will find tips and tricks to keep your humidity levels in your home in check all year long. 

Tip #1 Get a Dehumidifier 

If you are finding that your basement has too much moisture in the air, you can install a dehumidifier to get it under control. However, you need to make sure that all the windows and doors are properly sealed and then keep the space closed off until the job is done. 

Home Dehumidifier

Note: There are larger-sized dehumidifiers that can be used for an entire house; this can be effective if your moisture levels are quite high. 

Tip #2 Take Advantage of Your Air Conditioner 

Many people think that running the AC all the time is causing harm to the indoor air quality in their homes. However, air conditioners are pretty effective at removing humidity and moisture! Just make sure that the size of your AC unit can accommodate your home’s square footage.  

Tip #3 Install Humidity Monitors 

Take the time to pick up a few humidity monitors and install them in different areas of your home. For example, if you have an upstairs and a basement – you should install at least three to keep an eye on the moisture and humidity in that area of your home. 

You can find humidity monitors at your local hardware store or online at places like Amazon. They are relatively low in cost and can be a lifesaver when it comes to keeping your house comfortable all year round. 

Tip #4 Promote Ventilation 

The moment you see moisture building up, such as in the bathroom after a steaming shower or in a kitchen where you’ve been cooking all day, turn on the vent fans and allow the space to air out. If you don’t have a bathroom or kitchen vent fan, open the windows until the moisture levels have been reduced back to the normal range. 

Many people don’t think about the condensation that happens when hot water is being used for an extended time (shower, bath, etc.) and don’t use a fan or open any windows. In a matter of a short time, you will begin to see signs of mildew or mold growing if you don’t have proper ventilation. 

Tip #5 Check Your Insulation 

If you find that only one room in your home is having issues with the humidity, check the insulation! More often than not, improperly insulated homes are the cause of high humidity and moisture problems. This is the best way to stop any cold or warm air from escaping that area of your home, which will promote a healthy humidity level. 

Are There Other Ways To Control The Humidity In Your Home? 

There are some other things you can do to try and decrease the humidity in your house. If you want to have the perfect amount of humidity in your home all year long, then apply the above tips and take a look at the suggestions below. 

  • Caulking – All your faucets, sinks, tubs, toilets, etc., should have proper caulking around them to prevent moisture from getting into your walls or floors. In many cases, the caulking needs to be renewed or replaced every couple of years in areas that are used often, like the kitchen sink.
  • Weatherstripping – If you don’t have weatherstripping installed around your doors and windows, you are going to want to do that immediately. This is one of the best tricks for preventing cool or warm air from escaping your home. If you live in a warm climate, this is an absolute necessity! 
  • Install Fans – One of the best ways to control humidity in your home is to use ceiling fans in your bedrooms and other more significant areas, as well as bathroom fans when showering or taking steam baths. If you don’t have one in your bathroom, open the windows and door as quickly as possible, either during or immediately afterward.  
  • Filters ; Ducts – You should be changing your AC filters according to the manufacturer’s instructions and calling for yearly maintenance to make sure your unit is working efficiently. Also, be sure to clean your AC ducts or have a professional do it with your regularly scheduled maintenance. 
  • Switch Carpet to Tile – Unfortunately, carpet retains moisture and can be one of the reasons the humidity in your home is out of control. If possible, switch the rooms with carpet to either wood or tile floors, and you will see an immediate difference in the humidity levels in your home. 

Note: Switching your HVAC Unit or AC to Auto instead of ON can help keep your humidity under control. If your unit is constantly shutting on and off, adjust the temperature so that it reduces the amount of time it is starting and stopping. 


We may not be able to control the humidity outside, but we certainly can take steps to prevent it indoors. Having a comfortable home with the proper humidity and moisture levels is key to living your best life! 

Simply follow our tips and suggestions for lowering the humidity in your home, and you’ll be able to enjoy the indoors all year long.