Your bedroom temperature can make a surprisingly big difference to how comfortable you feel at night. A room that is too warm may make it harder to settle down and can contribute to restless sleep.
Your body naturally changes temperature as part of the sleep process, which is one reason a cooler bedroom is generally recommended for sleeping. But there isn’t one perfect temperature that works for everyone.
So how cool should your bedroom actually be? Let’s look at what the research suggests — and how you can find the temperature that works best for you.
What Is the Best Temperature for Sleep?
For most adults, a comfortably cool bedroom is generally better for sleep than one that feels excessively warm. However, research does not point to one exact bedroom temperature that is ideal for everyone.
Your ideal temperature depends on factors such as bedding, sleepwear, airflow, humidity and personal preference. A better approach is to keep the room comfortably cool and adjust the temperature until you can sleep without regularly feeling too hot or too cold.
Why Does Temperature Affect Sleep?
Your body temperature isn’t constant throughout the day. It follows a daily rhythm and begins to fall as your body prepares for sleep. This decrease is part of the natural transition from wakefulness to sleep.
A bedroom that is too warm can interfere with your body’s ability to release heat. You may feel uncomfortable, sweat, toss and turn or wake more frequently during the night.
Being too cold can also disturb sleep. If you’re shivering or your hands and feet feel uncomfortably cold, your body may have to work harder to stay warm instead of allowing you to rest comfortably.
The goal, therefore, isn’t simply to make your bedroom as cold as possible. It’s to create an environment that allows your body to regulate its temperature without leaving you feeling either hot or cold.
Is There One Perfect Temperature for Sleep?
Not necessarily. Sleep temperature is personal, and the temperature shown on your thermostat is only one part of how warm or cool you feel in bed.
Your bedding, pajamas, mattress, humidity and airflow can all affect your comfort. Age and individual differences can also influence how easily your body regulates temperature during the night.
Temperature is only one part of sleep comfort. If your mattress also feels too firm, read our guide on how to make a firm mattress softer.
Instead of trying to hit exactly 18°C, use it as a starting point and experiment. If you regularly wake up feeling hot, try lowering the room temperature slightly or using lighter bedding. If you wake up cold, adjust your bedding or increase the temperature a little.
Small adjustments are usually enough. The best temperature is ultimately one that lets you sleep comfortably without regularly waking because you feel too hot or too cold.
Signs Your Bedroom May Be Too Warm for Sleep
You don’t necessarily need a thermometer to notice that your bedroom is too warm. Your body may already be giving you clues during the night.
Possible signs include waking up sweaty, repeatedly throwing off the covers, feeling restless or waking during the night because you feel uncomfortably hot. You may also notice that you sleep better when the weather is cooler or when there is more airflow in the room.
Before making major changes, try simple adjustments such as lighter bedding, breathable sleepwear, opening a window when appropriate or lowering the thermostat slightly. Then pay attention to whether your sleep feels more comfortable over several nights.
Can Your Bedroom Be Too Cold?
Yes. Cooler doesn’t automatically mean better. A bedroom that leaves you shivering or feeling uncomfortably cold can also interfere with sleep.
Rather than heating the entire room significantly, you may be able to stay comfortable with appropriate pajamas, socks or an extra layer of bedding. This allows you to keep the surrounding air relatively cool while staying comfortably warm in bed.
The aim is balance: a cool sleeping environment without making yourself cold.
5 Practical Ways to Keep Your Bedroom Cool
1. Improve Airflow
If the weather and your surroundings allow it, opening a window or bedroom door can improve airflow and help warm air escape. A fan can also help circulate air and make the room feel more comfortable.
2. Choose Lighter Bedding
Heavy duvets and blankets can trap heat around your body. During warmer periods, try lighter bedding and adjust the number of layers so you can easily add or remove warmth during the night.
3. Wear Breathable Sleepwear
Your pajamas can affect how warm you feel just as much as your bedding. Lightweight, breathable sleepwear may help prevent you from becoming uncomfortably hot during the night.
4. Reduce Heat During the Day
On hot days, keeping curtains or blinds closed when direct sunlight reaches the bedroom can help prevent the room from heating up. When the outdoor temperature drops later, opening windows may help release some of the stored heat.
5. Experiment Instead of Chasing a Perfect Number
Use the temperature on your thermostat as a guide rather than a strict rule. Try small adjustments and pay attention to how comfortably you sleep over several nights.
Your ideal setup may also change with the seasons, so the temperature and bedding that work in winter may not be right for summer.
What About Humidity?
Humidity can also affect how comfortable your bedroom feels. When the air is very humid, sweat evaporates less easily, which can make a warm bedroom feel even hotter and more uncomfortable.
Very dry air can create different problems, such as a dry nose or throat. Rather than focusing on an exact humidity number, pay attention to whether the air in your bedroom feels unusually damp or dry and adjust ventilation or humidity when needed.
Temperature, airflow, bedding and humidity all work together, so improving one of these factors may be enough to make your sleep environment more comfortable.
Find the Temperature That Works for You
A cool bedroom can support comfortable sleep, but there is no single temperature that is perfect for everyone. Around 18°C (65°F) can be a useful starting point, but your own comfort should guide the final setting.
Experiment with small changes to the thermostat, bedding, sleepwear and airflow rather than changing everything at once. Pay attention to whether you wake because you’re hot or cold and adjust accordingly.
The goal isn’t to achieve a perfect number on the thermostat. It’s to create a bedroom where temperature is one less thing getting between you and a good night’s sleep.