Here’s The Definitive Best Humidity Level For Sleeping


When sleep is hard to come by, sleep coaches and doctors tend to encourage their clients and patients to dissect their sleep hygiene habits and look for opportunities. And while bedtime routines, light discipline, and temperature often top the list of tweaks for better sleep, most people probably don’t think about the best humidity level for sleeping. It may be an afterthought for many, but the moisture in your sleeping environment — or lack thereof, can affect your zzzs. 

How Does Humidity Impact Sleep? 

Ben Spielberg, M.S., a neuroscientist and founder of TMS & Brain Health in Los Angeles, tells Sleepopolis that humidity does, in fact, affect our sleep, but he notes the relationship between humidity and our health (including sleep) isn’t simple and linear. 

Humidity affects our ability to breathe, both while we’re awake and asleep because the oxygen density in the air is reduced by all of the water vapor that makes up the humidity,” says Spielberg. “Ultimately, this can lead to labored breathing, and when that happens during sleep, our quality of sleep diminishes. The body has to work harder to send oxygen to the brain, which can inhibit some of the deeper stages of rest we need to feel well-rested. [High humidity levels] can also make it harder to fall asleep in the first place because of the physical discomfort and labored breathing.” 

And research corroborates as much, showing that high humidity does all of the above and then some. A bump in the humidity can decrease your time in slow wave sleep (SWS) and rapid eye movement (REM) sleep, plus it can impair your overall sleep efficiency by increasing the duration of night awakenings. 

Beyond its ability to stymie your sleep, humidity can also lead to a host of other health issues, not the least of which is the proliferation of dust mites and mold, which thrive in moist, humid environments — so much so that it’s not uncommon for allergy and asthma symptoms to be exacerbated.

And while high humidity can impair your sleep, so too can dry air or low humidity. Dry air is notorious for irritating airways and mucous membranes, including your eyes, nose, and throat.  

How Do I Know If My Bedroom Is Too Humid or Too Dry? 

The good news is you don’t need a degree in advanced science to determine whether your sleeping environment is leaning humid or dry. You can do a visual inspection of your home and room and pay a little extra attention to how you feel from day to day.

Signs and Symptoms of a Humid Environment 

  • A damp feeling in the air
  • Musty smell
  • Condensation on windows and surfaces
  • You persistently feel dehydrated 
  • An uptick in allergy, asthma, and eczema symptoms

Signs and Symptoms of a Dry Environment  

  • Sore throat
  • Dried out mucous membranes (eyes, nose, throat)
  • Increased static electricity 
  • An uptick in allergy and asthma symptoms 
  • Frequent nosebleeds 
  • Dry skin

For those who prefer to work with more quantitative data, Spielberg recommends buying a hygrometer — a device that measures humidity. Noting that household thermostats may not be completely accurate throughout the home, Spielberg says hygrometers eliminate the guessing game and make it easy to accurately keep track of humidity levels in your bedroom. 

Best Humidity Level For Sleeping

“It’s important that the air in your bedroom isn’t too dry since dry air dehydrates your mouth, lips, and nose, which can lead to discomfort and more trouble sleeping,” says Spielberg. “To promote the best sleep possible, the ideal humidity level in your bedroom should be between 40 and 50 percent.” 

The American Heart Association also warns that high heat and humidity can be hard on older hearts, so maintaining humidity levels around 40 to 50 percent is especially important for those with heart disease and high blood pressure, as the heart has to work harder to pump blood efficiently throughout the body when the mercury soars.

Tips For Maintaining Optimal Humidity Levels

Once you’ve figured out if your room is too humid or too dry, your next steps would be to balance things out and maintain optimal humidity levels in your bedroom. 

To Boost Humidity Levels

Add a Humidifier 

Humidifiers are relatively inexpensive and, therefore, a common way to add moisture to indoor living spaces. The caveat here is that they’re also quite effective, so if this is your solution for boosting humidity levels in your bedroom, be sure to keep a watchful eye on the space. You don’t want to go from too dry to overly damp — neither one is beneficial to your sleep. It’s all about balance. 

Tinker with the Temperature

Indoor heating can supercharge the evaporation of moisture in the air, causing a room to dry out. To help maintain higher moisture levels, try setting your thermostat a few degrees lower.

Incorporate Plants into Your Decor

While plants can do plenty to tszuj your space, they have a nice added benefit you’re probably not aware of — plants can increase the humidity in a room. Jade and spider plants are two great options. 

To Lower Humidity Levels

Identify and Address Home Repairs 

Water leaks and poor ventilation are two of the most common culprits for high humidity in a home — this is especially true of older homes. While fixing these issues will boost your home’s value, it could also lead to better sleep. 

Get the Air Moving 

Opening windows from time to time or keeping room doors open gets stagnant air moving. You’d be surprised how far something so small can go toward keeping humidity levels in check. 

Crank up the AC

ACs often get a bad rap for their exorbitant energy costs, but in addition to lowering the ambient temperature, many air conditioners also work like dehumidifiers — they not only cool your space, they also remove moisture from the air. 

Try Some Bedding Swaps

If you’re sleeping in a humid environment, synthetic bedding is not your friend. While some fabrics can keep you cool and dry, others can exacerbate night sweats. To stay cool, dry, and fast asleep, try switching to naturally breathable bedding like cotton and rayon. Better yet, opt for moisture-wicking or cooling sheets, bedding, and mattresses. 

The Last Word From Sleepopolis 

While light and noise discipline often steal the show in any discussion on sleep hygiene, research shows that humidity matters too. Not only can high humidity decrease time spent in slow-wave and rapid-eye-movement sleep, but it can also stretch out night-time wakings. For optimal sleep, humidity levels in your sleeping environment should be somewhere between 40 and 50 percent. 

Sharon Brandwein

Sharon Brandwein

Sharon Brandwein is a Certified Sleep Science Coach and a freelance writer. She specializes in health and beauty, parenting, and of course, all things sleep. Sharon’s work has also appeared on ABC News, USAToday, and Forbes. When she’s not busy writing, you might find her somewhere curating a wardrobe for her puppy.

Leave a Comment