What Is the Best Room Temperature for Sleep?
The most commonly recommended bedroom temperature for adults is about 65°F (18°C), within a range of roughly 65 to 68°F (18 to 20°C). A cool room helps because your core body temperature needs to drop for you to fall asleep and stay asleep. For babies, a slightly warmer room, up to about 69°F (20.5°C), is usually suggested.
Key facts
- Your core body temperature starts to fall about 2 hours before you fall asleep and reaches its lowest point in the early morning.
- A hot bedroom can reduce REM sleep and deep sleep and cause more awakenings.
- The ideal varies with bedding, sleepwear and humidity. If you sleep well, your room is fine.
- A warm bath or shower 1 to 2 hours before bed can help you fall asleep faster.
Why temperature affects sleep
Your body temperature follows a daily rhythm controlled by your body clock. In the evening, blood vessels in your hands and feet widen and release heat, and your core temperature drops. That drop is one of the signals that helps you fall asleep. It continues through the night and reaches its lowest point a few hours before you usually wake.
A warm room makes it harder for your body to shed heat, so sleep tends to be lighter and more broken. Research reviewed by Kazue Okamoto-Mizuno and Koh Mizuno in 2012 found that heat exposure increases wakefulness and decreases both deep (slow-wave) sleep and REM sleep. A very cold room can also disturb sleep, but bedding usually protects against cold better than against heat.
Recommended temperatures
| Who | Suggested room temperature |
|---|---|
| Adults | 65–68°F (18–20°C) |
| Babies | Slightly warmer, up to about 69°F (20.5°C), with no loose blankets |
| Older adults | May prefer slightly warmer, as the body’s temperature control changes with age |
For babies, follow safe sleep advice: place them on their back in their own crib or bassinet, with no pillows or loose bedding, and don’t overdress them.
How to sleep in hot weather
- Close blinds and curtains during the day to keep sunlight out, and open windows at night if it’s cooler outside.
- Use a fan to move air across you.
- Use light cotton or linen bedding and sleepwear.
- Take a lukewarm shower before bed.
- Keep a glass of water by the bed.
- Sleep on the lowest floor of your home if you can, as heat rises.
Does a warm bath help?
Yes, for many people. A 2019 review by Shahab Haghayegh and colleagues found that a warm bath or shower of about 104 to 109°F (40 to 42.5°C), taken 1 to 2 hours before bed, helped people fall asleep faster. The warm water brings blood to the skin, which then helps the body cool down more quickly afterwards.
Other parts of a good sleep environment
- Dark: blackout curtains or an eye mask, especially for early sunrises or day sleep after night shifts.
- Quiet: earplugs or white noise.
- Comfortable: a supportive mattress and pillow.
- Regular: the same bedtime and wake-up time each day. Use the sleep calculator to set yours.
Sources
- Sleep Foundation: Best temperature for sleep
- Okamoto-Mizuno K, Mizuno K. Effects of thermal environment on sleep and circadian rhythm. Journal of Physiological Anthropology, 2012
- Haghayegh S et al. Before-bedtime passive body heating by warm shower or bath to improve sleep: a systematic review and meta-analysis. Sleep Medicine Reviews, 2019
- AASM Sleep Education: Healthy sleep habits
Frequently asked questions
Is 70°F too hot for sleeping?
It’s slightly above the commonly recommended range. Many people sleep fine at 70°F with light bedding, but if you wake up hot, try turning it down a couple of degrees.
Is it better to sleep in a cold room?
A cool room is better than a warm one, but a room that’s so cold you can’t get comfortable will also disturb sleep.
Why do I wake up hot at night?
A warm room, heavy bedding, alcohol, a late heavy meal or hormonal changes such as menopause can all cause it.
