The best bedroom environment for sleep is cool, dark, and quiet. Sleep specialists suggest a room temperature of 60 to 67°F (15 to 19°C). The World Health Organization recommends less than 30 decibels of noise in bedrooms at night. Research shows that even moderate light during sleep raises heart rate. Most of the fixes are simple and cheap: close the curtains fully, cover or remove light sources, use a fan, and try earplugs. This guide explains what the evidence says about light, temperature, and noise, with a checklist you can use tonight.
Key Takeaways
- A cool room of 60 to 67°F (15 to 19°C) suits most adults. Above 70°F (21°C) is too hot for good sleep.
- In one study, a single night of sleeping in moderate light raised heart rate and increased insulin resistance the next morning.
- WHO guidelines recommend less than 30 dB(A) of noise in bedrooms at night.
- If you can see things clearly in your bedroom at night, it is probably too light.
- The right setup is personal, so try changes one at a time and keep what works.
The Ideal Bedroom at a Glance
| Factor | Target | Simple fix |
|---|---|---|
| Temperature | 60 to 67°F (15 to 19°C) for adults | Fan, open window, lighter bedding |
| Light | As dark as possible | Fully closed curtains, eye mask, cover device lights |
| Noise | Less than 30 dB(A) | Earplugs, phone on silent, steady background sound |
| Night light, if needed | Dim, amber or red, close to the floor | Low plug-in light away from the bed |
| Devices | Out of sight | Phone face down or outside the room |
Why Your Bedroom Affects Your Sleep
Your body clock takes cues from your surroundings. The National Heart, Lung, and Blood Institute explains that light, darkness, and other cues help determine when you feel awake and when you feel drowsy. A bedroom that is bright, warm, or noisy sends your body mixed signals at the time it should be winding down. Our guide to circadian rhythm explains how this clock works.
Light: Keep Your Bedroom Dark
What Happens When You Sleep With the Lights On
A Northwestern University study compared a night of sleep in moderate light (100 lux) with a night in dim light (3 lux). After a single night in the lighter room:
- heart rate was higher during sleep
- insulin resistance was higher the next morning
- participants were not aware of any of these changes
The researchers explained that light kept the body in a more alert state even though the person was asleep. Heart rate normally falls at night, and in the lit room it did not fall as it should.
The researchers also noted that light at night is common. Up to 40% of people sleep with a bedside lamp on, a light on in the bedroom, or the television on.
This was a small study covering a single night, so it shows a short-term effect. It does not prove long-term harm on its own, but it supports the standard advice to sleep in a dark room.
How to Make Your Bedroom Darker
The Northwestern researchers and the UK’s National Health Service (NHS) suggest:
- Close curtains or blinds fully. Use blackout shades if outdoor light is a problem.
- Wear an eye mask if you cannot block the light.
- Move your bed so outdoor light does not shine on your face.
- Keep clocks out of view and place your phone face down.
- Turn off the television before you fall asleep.
A simple test from the lead researcher: if you can see things really well, it is probably too light.
If You Need a Night Light
Some people need a light for safety, especially older adults. The Northwestern team advises:
- Choose a dim light and place it close to the floor.
- Pick amber, red, or orange light, which is less stimulating for the brain.
- Avoid white or blue light, and keep any light far from the sleeping person.
Screens are a separate source of evening light. See our article on how screen time affects sleep.
Temperature: Keep It Cool
The Best Temperature for Sleep
Cleveland Clinic recommends keeping your bedroom at 60 to 67°F (15 to 19°C). Its sleep psychologist suggests thinking of your bedroom as a cave: cool, dark, and quiet.
| Who | Suggested bedroom temperature |
|---|---|
| Adults | 60 to 67°F (15 to 19°C) |
| Babies and toddlers | 65 to 70°F (18 to 21°C) |
Why Temperature Matters
Your core body temperature drops as part of falling asleep. Cleveland Clinic explains what happens at either extreme:
- Too hot (above 70°F or 21°C). A hot or humid room causes restlessness and makes it harder to fall and stay asleep. Heat is described as a major disruptor of REM sleep.
- Too cold (below 60°F or 15°C). Your body works to warm itself up, which puts extra demand on your cardiovascular system.
If your room becomes uncomfortably hot or cold, you are more likely to wake up.
How to Keep Your Bedroom Cool
- Keep a fan in the room.
- Use breathable sleepwear, sheets, and blankets suited to the season.
- Open a window if it is safe to do so.
- Avoid caffeine and sugary foods close to bedtime. Cleveland Clinic notes that these can raise body temperature.
If you live in a hot climate and cannot reach the suggested range, aim for as cool and well aired as you comfortably can. A fan and light cotton bedding make a real difference.
Noise: Keep It Quiet
How Quiet Should a Bedroom Be?
The World Health Organization states that its guidelines recommend less than 30 A-weighted decibels, written dB(A), in bedrooms during the night for good quality sleep. For noise outside the bedroom, the guideline is a yearly average of less than 40 dB(A) at night.
WHO lists sleep disturbance and cardiovascular effects among the health problems noise can cause. Some groups are more vulnerable:
- children, who spend more time in bed than adults
- older people and people with long-term illness, who are more sensitive to disturbance
- shift workers, whose sleep is already under strain
You can estimate the noise level in your bedroom with a free sound meter app on your phone. These apps are not precise, but they give a rough idea.
How to Reduce Bedroom Noise
The NHS suggests:
- earplugs if noise is a problem
- putting your phone on silent to avoid interruptions
- background sounds such as rainfall, gentle music, or white noise
Other practical steps include closing windows on the noisy side of the home, using heavy curtains, and moving your bed away from a shared wall.
Comfort and Bedroom Setup
There is less firm research on bedding than on light, temperature, and noise, so treat these as practical suggestions:
- Mattress and pillow. Choose what keeps you comfortable and free from aches. Replace them when they sag or cause discomfort.
- Bedding. Use breathable fabrics and change the weight of your covers with the season.
- Clutter and work. Keep work materials out of the bedroom where you can, so the room feels like a place to rest.
- Devices. Charge your phone outside the bedroom or across the room.
Bedroom Checklist for Tonight
- Close the curtains or blinds completely.
- Cover or switch off standby lights and turn clock displays away.
- Put your phone on silent, face down, and out of reach.
- Set the room to a cool temperature or switch on a fan.
- Choose bedding that suits tonight’s weather.
- Have earplugs or steady background sound ready if noise is likely.
- Turn off the television before you settle down.
Pair this with a calm wind-down. Follow our night routine for better sleep.
When the Bedroom Is Not the Problem
A good sleep environment helps, but it will not fix every sleep problem. The NHS notes that the right environment is personal and suggests trying different things to see what works. If you have improved your bedroom and still sleep badly, look at your wider habits in our guide to improving sleep quality naturally. See a doctor if sleep problems last more than a few weeks, or if you snore loudly and feel exhausted during the day.
Frequently Asked Questions
What is the best bedroom environment for sleep?
A room that is cool, dark, and quiet. Aim for 60 to 67°F (15 to 19°C), as little light as possible, and minimal noise.
What is the best temperature for sleep?
Cleveland Clinic suggests 60 to 67°F (15 to 19°C) for adults and 65 to 70°F (18 to 21°C) for babies and toddlers.
Is it bad to sleep with the lights on?
Research suggests it is better not to. In one study, a single night of sleep in moderate light raised heart rate and increased insulin resistance the next morning.
Is it bad to sleep with the TV on?
A television adds both light and sound to your bedroom. Switch it off before you fall asleep, or use a sleep timer.
What colour light is best for sleep?
If you need a light, researchers suggest a dim amber, red, or orange light placed close to the floor. Avoid white or blue light.
Does noise affect sleep even if it does not wake you?
WHO lists sleep disturbance and cardiovascular effects among the health problems linked to noise, and it recommends less than 30 dB(A) in bedrooms at night.
Does white noise help you sleep?
It helps some people. The NHS lists background sounds such as rainfall, gentle music, or white noise among things you can try.
The Bottom Line
Light, temperature, and noise all shape how well you sleep. Make your bedroom as dark as you can, keep it cool, and cut down on noise. Start with the easiest change, such as closing the curtains fully or moving your phone, and add others one at a time.
Sources
- Northwestern University. Close the blinds during sleep to protect your health.
- Cleveland Clinic. What’s the Best Temperature for Sleep?
- World Health Organization Regional Office for Europe. Noise fact sheet.
- National Health Service (UK). How to fall asleep faster and sleep better.
- National Heart, Lung, and Blood Institute. How Sleep Works: Your Sleep/Wake Cycle.
This article is for general information only and is not medical advice. Read our full Disclaimer.
The Health Gardeners Team researches and writes practical wellness content on sleep, nutrition, energy, and daily habits. Our articles are based on published research and guidance from reputable health organizations, and we review and update them regularly. We are not medical professionals, and our content is for general information only. It is not a substitute for advice from a qualified healthcare provider. Learn more about us.
