What is The Best Humidity Level for Sleeping?

There are many ways to create the perfect bedroom environment for sleep, and a few simple tweaks can make all the difference.

Adjusting light levels, minimizing noise, and setting the correct temperature are important considerations. Still, one often overlooked factor in optimizing sleep is humidity.

The amount of moisture in the air doesn’t just play a huge role in our sleep quality; it also impacts our overall health and wellbeing.

I’ll cover everything you need to know about creating the perfect humidity levels in your bedroom in this post. I’ll explain how humidity is measured and look at the research about the best levels to aim for to help us drift off at night. Plus, I’ll give you some tips on raising or lowering the humidity in your sleep environment, so you can wake up feeling well-rested and ready to face the day.

How is Humidity Measured?

Humidity is measured in two ways; relative humidity and absolute humidity.

The relative humidity is the amount of water vapor in the air relative to the temperature. In contrast, absolute humidity refers to the density of moisture in any cubic meter, regardless of how hot or cold it is.

The warmer the air, the more water vapor it can hold. So, when comparing a warm room and a cold room with the same absolute humidity, the cold room will have a higher relative humidity level.  Relative humidity tells us how humid the air feels, and it’s the most accurate measure to use in any indoor environment, including in your bedroom.

What Happens When Your Bedroom is Too Humid?

What Happens When Your Bedroom is Too Humid?

Too much moisture in the air makes us feel uncomfortable, and if you’ve ever tried to fall asleep in a humid room, you’ll know how difficult it can be.

Even if you manage to drift off, it’s not unusual to wake up in the middle of the night to find your sheets drenched in sweat.

But sleeping in a humid room has adverse effects that go beyond how comfortable we feel.

Our sleep cycles can be broken down into four stages; three different stages of non-rapid eye movement(NREM) and a fourth and final stage of rapid eye movement (REM).

The third NREM sleep stage is often called ‘slow-wave sleep.’ This NREM stage is essential for our immune systems and helps our bodies to heal and repair. Our breathing and heart rate slow down, our core temperature drops, and our brain activity reaches its lowest level.

The fourth stage, REM, is just as crucial to our health. This is when our breathing, heart rate, and brain activity all begin to speed up, and, as the name suggests, our eyes begin to move rapidly behind our lids.

This is the dream stage of sleep. It plays a central role in emotional processing, memory consolidation, and brain development.

But if the air is too humid, you’re much less likely to fall asleep and stay asleep, making it impossible to reach those all-important NREM and REM sleep stages.

This leaves us feeling exhausted throughout the day and, over time, can have a disastrous impact on our physical and mental health.

Humid environments are the perfect breeding ground for mold and dust mites if all that wasn’t bad enough.

We spend almost a third of our lives in our bedrooms, either sleeping or trying to fall asleep. If these moisture-loving spores and microscopic creatures are allowed to multiply, it can lead to some pretty severe consequences.

You may develop allergies, and certain types of mold can even cause the onset of asthma and other serious health conditions. So, suppose you live in a muggy part of the world. In that case, it’s important to keep your bedroom’s humidity levels in check, not only for a good night’s sleep but also for your overall health and wellbeing.

What Happens if Your Bedroom is Too Dry?

While too much humidity can disrupt our sleep and circadian rhythms, too little can be just as harmful.

Dry air can irritate the respiratory passages, make breathing more difficult, and even increase respiratory tract infections.

It can also irritate our eyes, dehydrate our skin, and lead to the overproduction of sebum as the body compensates for the lack of moisture on the epidermis.

What is the Ideal Humidity Range for Sleep?

What is the Ideal Humidity Range for Sleep?

As you can see, a bedroom that is too dry or too humid not only prevents us from getting the sleep we need; it also negatively impacts our health in a myriad of ways.

So, what’s the sweet spot where the moisture level in the air is just right?

Well, that depends on who you ask.

For example, the Environmental Protection Agency says the relative humidity of any indoor space should be between 30% and 50%. But many experts believe these figures are based on outdated evidence and instead suggest parameters of 40% to 60%. But despite conflicting opinions from the scientific community, it’s universally accepted that the relative humidity levels should sit below 60%, not just in your bedroom but in any indoor space.

How to Test Humidity Levels in Your Bedroom?

So now that we know how humid our bedrooms should be, how do we test the air and determine whether our sleep environment is just right?

The easiest way to measure relative humidity is with an indoor humidity monitor, often called a hygrometer. These are available at most major hardware stores and are generally inexpensive to buy.

But before you go rushing out to Home Depot, it’s worth checking your thermostat to see if it measures relative humidity alongside the temperature, as many of the most recent models do both.

How to Increase the Humidity Levels in Your Bedroom?

If you live in a dry climate, then you may find that your bedroom’s relative humidity falls short of the minimum 30-40%.

So what can you do about it?

There are several ways you can increase the moisture content in the air, including the tried and tested methods below.

1. Use a Humidifier

This is the most obvious and effective way of adding extra moisture into the air in your bedroom. Just be sure to keep an eye on your humidity monitor or hygrometer to ensure that you’re not swinging too far in the other direction of the scale.

2. Make Your Own Humidifier

Leaving a container of water next to heating vents or radiators in your bedroom will cause the moisture to evaporate, raising the humidity levels similar to a humidifier, without the expensive price tag.

3. Collect Houseplants

Collect Houseplants

Well-watered plants are a great way to naturally increase relative humidity levels indoors. They also help to purify the air and add a fresh feel to your bedroom decor.

4. Dial Down The Thermostat

Artificial heat sources can banish moisture droplets in the air and reduce the relative humidity to an uncomfortable level.

So, consider lowering the thermostat by a few degrees and see if you notice an improvement.

5. Air-dry Your Clothes Inside

Rather than using the dryer, try hanging your laundry on an airier inside your bedroom and letting them dry naturally. This will add moisture to the air and save you money on your energy bills.

How to Decrease the Humidity Levels in your Bedroom?

How to Decrease the Humidity Levels in your Bedroom?

If you live in a humid climate, you’ll know just how difficult it can be to fall asleep when the moisture levels in the air are too high.

So what are the most effective ways of drying out your bedroom to get a good night’s sleep?

Here are a few suggestions…

1. Use a Dehumidifier

Waykar 2000 Sq. Ft Dehumidifier for Home

These powerful machines can suck an incredible amount of moisture from the air. But just like when using a humidifier, you’ll need to regularly monitor your hygrometer to make sure you don’t overdo it.

2. Turn on The AC

Air conditioning sucks both moisture and heat from the air, so if you’re trying to sleep in a hot and humid environment, turning on the AC can really help.

But be careful; research has shown that when the AC unit is pointed directly towards you, it can negatively impact your sleep. So pay attention to the airflow direction and avoid using the AC when it’s not absolutely necessary.

3. Open The Windows

Open The Windows

Sometimes, it’s not the outside environment causing an excess in humidity. Often, poor ventilation can be to blame. So, if the air outside is dryer than the air inside your bedroom, try opening a few windows to allow moisture to escape.

4. Switch on Extraction Fans

Activities like cooking, showering, and bathing can increase the humidity levels in your home, and if you sleep close by to the kitchen or bathroom, then there’s a good chance your bedroom could be affected, too.

Be sure to turn on extraction fans in these rooms to reduce moisture buildup before it has a chance to accumulate.

5. Check For Leaks

Check For Leaks

If you live in an older property, often, leaking pipes and faucets can be to blame for excess moisture in the air.

Look out for damp spots on your walls and ceilings, which can all indicate a hidden problem with the pipework.

6. Check Your Ventilation

Dust and debris can clog up extraction units and ventilation systems, so check them regularly to see if they need cleaning, fixing, or replacing.


Humidity levels can have a profound effect on the quality of our sleep. Keeping your bedroom at a relative humidity reading of 40-60% will increase your chances of falling asleep and staying asleep for longer. Plus, your overall health could benefit, too.

Sarah Wagner

I'm Sarah Wagner, and I founded Sweet Island Dreams in 2022. It's a blog dedicated to helping people mental vacation virtually anytime they want. By providing information about the best sleep of your life, I help people drift away to paradise without ever having to leave their bed!

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