HouseFresh is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more

Why is my house so humid?

Updated on November 14, 2023
Written by
Paul Allen
Paul is a staff writer for HouseFresh, with a focus on product recommendations and advice for smokers and apartment dwellers. He started writing in November 2020, when he joined the content production team at NeoMam Studios (our parent company).

High humidity, usually caused by warm climates and a range of everyday activities, can wreak havoc on your home and health as excess moisture leads to mold, mildew and bacteria-filled air. 

Regulating humidity in your house couldn’t be easier, however. Investing in a quality dehumidifier and increasing ventilation and insulation will turn your home into a happier and healthier habitat for you and your family.

We all know that sticky feeling. When humidity creeps up, moisture levels peak and homes turn from heaven to hell. 

But beyond feeling uncomfortable, more serious consequences can occur when humidity rises above 60%. From providing a fertile breeding ground for bacteria and invaders such as dust mites and cockroaches, to attacking the home itself, spreading mold and wood rot throughout the home’s structure and your belongings.

To help you keep these issues at bay, we’ll unpack why your home might feel so humid and what you can do to keep your space in the humidity sweet spot of 40-60%.

4 Reasons your home is humid

Is your indoor environment feeling hot, moist and stuffy? Here are four key factors that might be making your home so humid. 

1. The outdoor weather is getting inside

No matter where you live (North Pole excluded), warm weather, coupled with high humidity, often takes hold in the summer months. This can feel like hot, heavy and humid air is infiltrating every space you previously thought safe. 

And that’s because it is. 

Moisture-rich air can seep into homes through doors, windows and cracks or gaps in the exterior of the building. Those living in naturally humid environments will face the brunt of this for extended periods of the year. Sorry, Florida.

Humidity can even rise through the ground! On hot days, heat draws moisture from the water table to the surface, which can exacerbate humidity indoors if you live near a lake or river.

2. Excess moisture from household activity

Picture the scene. Mum is enjoying a nice hot bath, dad is rustling up his famous pasta carbonara while the kids tackle the dirty dishes. 

Each of these activities adds moisture to the air. 

But there are plenty more humidity-inducing household activities that we carry out in our daily lives. Here’s a look at the worst offenders:

🌱 Watering plants💦 Plants release 97% of the water you give back into your environment.
🧽 Cleaning💦 Doing the dishes alone can create two pints of excess moisture.
⚠️ Propane tanks💦 For every lb of propane burnt, you can expect 1.8 lbs of water vapor.  
🧺 Electrical appliances 💦 Dishwashers and washing machines use high-temperature water. One load equates to a pint of airborne moisture.
🛁 Bathing💦 Even a quick shower or brisk bath can add two pints to your air
🍝 Cooking💦 Boiling pasta for just 10 minutes can add over 100 grams of steam to the air. 
👕 Drying laundry💦 Drying wet clothes indoors is the worst offender. This can add as much as nine pints of moisture.
Making a cup of tea or coffee💦 By boiling a pint of water in a kettle, you’ll produce 10 grams of steam (approx 2%). 

3. People

As we breathe, sweat and talk, water vapor is released into the air. 

The average adult takes 20,000 breaths daily, meaning moisture can soon accumulate, especially in homes with more than one resident. 

Studies from University College London state that perspiration and breathing produce between two and three pints of moisture in a 24-hour period. 

4. Your house is poorly ventilated 

With all the airborne moisture created inside your home, this will become condensation without adequate ventilation. Collecting on walls, windows and a range of other surfaces. 

By ensuring that water vapor has a chance to escape, you will enable your home to breathe and regulate moisture levels much more effectively.  

Vents and extractor fans are vital in high-humidity hotspots such as the bathroom or kitchen. While keeping these ventilation points clear of debris will keep air flowing freely. 

Tips for reducing humidity indoors

Whether you’re boiling potatoes or plain, old breathing – humidity can occur from just about anywhere. Even when the weather outside is cool and dry. 

But there are measures you can take to reduce excess moisture and keep high humidity at bay. 

Take a look at these four fool-proof methods below:

✅ Vamp up ventilation 

If you’re experiencing high humidity when levels outdoors are low, then cracking a window when taking a shower or cooking should be your first port of call. Increasing ventilation throughout your home whenever there is a cool breeze will also help to relieve issues caused by excess moisture. 

By opening windows or doors, you will provide an escape route for humid air, while extractor fans, HVAC systems and room vents will also provide relief if opening a window isn’t always an option. 

✅ Improve insulation

Preventing humid air from entering your space is the best defense from the most significant source affecting the home: the climate. 

Sealing gaps around doors and windows and aiming to keep your space as airtight as possible when humidity rises will create a cool and comfortable environment inside the home. 


If you’re affected by excess moisture inside the home, you can cut down on condensation by insulating cold surfaces, such as the inside of external walls and crawl spaces, as well as wrapping up pipes. 

✅ Maximise maintenance 

Keeping on top of maintenance can reduce possible sources of moisture in your home. Check your gutters for blockages, fix leaky pipes and ensure vents and ducts inside the house are in tip-top shape.

✅ Purchase a hehumidifier

Dehumidifiers cool hot, moist air, causing water vapor to condense and collect inside the unit, leaving cool, dry air to be redistributed inside your space. 

This is a certified miracle cure for homes with excess moisture. But not all dehumidifiers were created equal. Ensure the unit you opt for can work its magic in your home, as an underpowered dehumidifier used in a large space will struggle to circulate the air and, therefore, make less of an impact. 


If you think a dehumidifier is the right choice for you, check out the Honeywell TP30WKN for small to medium sized spaces (32 pints) or the Moiswell Defender XP70 for basements and larger areas (145 pints).

Final thoughts 

Humidity is a hindrance in many people’s lives. It can be uncomfortable and even harmful to our health and home when it creeps above the ideal range of 40-60%. 

Investing in a dehumidifier, weatherproofing and maintaining your space can reduce exposure to the adverse climate, creating a more harmonious home. But be sure to look for a unit that is suitably powered for your space and capable of removing enough excess moisture.



About the author

Paul Allen

Paul is a staff writer for HouseFresh, with a focus on product recommendations and advice for smokers and apartment dwellers. He started writing in November 2020, when he joined the content production team at NeoMam Studios (our parent company).