sleep foundation
The National Sleep Foundation

Medically Reviewed by

The National Sleep Foundation

Written by

The National Sleep Foundation

The climate in your bedroom plays an important role in helping you sleeping more soundly. You may already know that your body temperature naturally drops while you are sleeping, making a cooler climate more snooze-inducing than a warm one. But temperature isn’t the only thing that matters when it comes to regulating your bedroom environment. The right level of humidity is important, too.

What Is Humidity?

The word humidity often brings to mind images of summertime. During these months, as the mercury rises, so does the amount of moisture in the air. The combination of the two makes summer weather feel even more oppressive, since it is harder for your body to evaporate sweat in order to cool itself when the air is already saturated with water. This difficulty in self-regulating your body’s temperature is also why on a warm, humid nights you may struggle to fall and stay asleep. What’s more, over time dampness in the air can contribute to mold growth and allergies, causing even greater sleep problems.

Dealing with Dampness

If you have an air conditioner, running it in warm weather can help to rid the air of excess moisture. You don’t need to leave it on 24/7: A few hours of cooler, drier air when you first go to bed could help you better regulate your body’s temperature and sleep more soundly for the rest of the night. No AC? Use fans to increase airflow or consider running a dehumidifier to suck dampness out of the air.

Some Moisture Is Good

Too little humidity isn’t ideal for sleep either, though. Dry air, most common in the winter or in arid, desert-like climates, can lead to irritated nasal passages, sneezing, stuffy noses, and cracked lips, and may even increase suffering from colds and other viruses. Like an engine without proper oil lubrication, breathing in dry air can irritate your throat and trigger fits of coughing or even gagging, which in turn makes sleeping difficult.

How to Increase Humidity

To boost the humidity in your bedroom during the winter, try using a humidifier while you sleep. Because allergens and bacteria can breed in dirty water reservoirs, consider using distilled water, change the water in your humidifier often, and clean the apparatus every three days to protect yourself.

The Perfect Balance

So what’s the sweet spot for sleep-enhancing humidity? Between 30 and 50 percent is the ideal range in which the air is moist enough for easy breathing, but dry enough to not feel oppressive. To keep track of the relative humidity in your bedroom, purchase a device called a hygrometer sold at hardware stores and department stores (also built in to some humidifiers).