A baby’s room can feel comfortable at bedtime and become noticeably warmer or cooler a few hours later. Changes in outdoor temperature, heating, air conditioning, ventilation, and even the position of the crib can all affect the sleep environment overnight.
That is why managing baby room temperature is not simply about setting the thermostat before bed. The goal is to create a comfortable sleep environment, anticipate how the room may change during the night, and make sure your baby does not become too warm or too cold.
With a room thermometer, appropriate sleepwear, and a few simple adjustments to heating, cooling, and airflow, you can make overnight temperature changes much easier to manage. This guide explains what temperature to aim for, how to keep the room comfortable throughout the night, and how to tell whether your baby needs an adjustment.
What Temperature Should Your Baby’s Room Be for Sleep?
A useful target for baby room temperature is 16–20°C (61–68°F). This range is recommended by The Lullaby Trust and is also used in NHS safer-sleep guidance.
However, you do not need to maintain exactly the same temperature every minute of the night.
Think of 16–20°C as a reference range. Your baby’s comfort also depends on what they are wearing, the insulation of their sleep bag, airflow in the room, and whether there is a nearby source of heat.
The key safety consideration is avoiding overheating. Safe to Sleep, a U.S. government campaign led by NICHD, notes that babies who become overheated have a higher risk of SIDS and that over-bundling can contribute to overheating.
Because it can be difficult to judge a room accurately just by how it feels, a room thermometer is useful. The Lullaby Trust recommends using one in rooms where your baby sleeps.
Why Baby Room Temperature Can Change Overnight
The temperature you check at bedtime may not represent the room conditions several hours later.
A bedroom can become cooler overnight because:
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The outdoor temperature drops.
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Central heating switches off.
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The room loses heat through windows or exterior walls.
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Air conditioning continues running after the rest of the home has cooled.
The opposite can also happen. A room may become warmer because:
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Heating switches on during the night.
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The room retains heat accumulated during the day.
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Doors and windows remain closed, reducing airflow.
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The cot is positioned near a radiator or another heat source.
You do not need to eliminate every small temperature fluctuation. The practical goal is to avoid large changes and make sure your baby’s clothing remains suitable for the conditions.
How to Keep Your Baby’s Room at a Comfortable Temperature All Night
A few simple adjustments can make maintaining a comfortable baby room temperature overnight much easier.
1. Check the temperature before bedtime
Start with the actual room temperature rather than guessing.
Check the thermometer as part of your bedtime routine, then choose your baby’s sleepwear based on that reading.
If your home tends to cool or warm significantly overnight, checking the room again when you naturally wake for a feed or diaper change can help you understand how much the temperature changes.
You generally do not need to wake a comfortable, healthy sleeping baby simply to check the thermometer.
2. Place the thermometer in a useful location
Avoid placing the thermometer directly beside:
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A radiator
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A heater
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An air-conditioning vent
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A fan
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A sunny window
These spots may be hotter or cooler than the area around your baby’s sleep space.
Instead, position it where it gives you a reasonable idea of the general temperature in the room.
3. Keep the crib away from direct heat and cold air
Where the crib sits can affect how warm your baby feels even if the room thermometer shows a comfortable temperature.
Avoid positioning your baby directly beside radiators, portable heaters, fireplaces, or strong air-conditioning vents.
The goal is to maintain a generally comfortable room, rather than heating or cooling your baby directly.
4. Use heating or air conditioning to manage the room, not the baby
Heating and air conditioning can be useful when the room becomes too warm or too cold.
If you use them, focus on regulating the overall room temperature. Avoid directing strong streams of hot or cold air toward the crib.
It may also help to consider how your system behaves overnight. For example, if your air conditioner automatically lowers the room temperature several degrees after midnight, your baby’s bedtime clothing should account for that expected change.
5. Improve airflow when the room is too warm
During warm weather, it may not always be possible to keep the room within the recommended range.
The Lullaby Trust advises using lighter clothing and bedding and, when safe, opening a bedroom door or window if the room is difficult to cool. A fan may also be used, but it should not be aimed directly at your baby.
Closing curtains or blinds during the hottest part of the day can also help prevent a sunny bedroom from storing excess heat before bedtime.
6. Avoid trying to warm a cool room with excessive bedding
When parents notice the room becoming cooler overnight, it can be tempting to add heavy blankets or several layers.
Instead, choose appropriate sleepwear before bedtime and adjust it if necessary.
Loose bedding also introduces separate safe-sleep concerns. The AAP recommends a firm, flat sleep surface with only a fitted sheet and no loose blankets, pillows, toys, bumpers, or other soft objects in the baby’s sleep space.
What to Do If the Room Gets Too Hot or Too Cold Overnight
Even with planning, the room may occasionally move outside your expected temperature range.
If the room becomes too warm
If your baby’s room is warmer than expected:
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Check your baby’s chest or neck for signs of overheating.
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Reduce unnecessary clothing layers.
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Use lighter sleepwear when appropriate.
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Use a fan for room circulation without directing it at your baby.
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Improve airflow safely.
If the room is above 20°C, do not panic simply because the thermometer is outside the recommended range. Focus on preventing your baby from becoming too warm.
If the room becomes too cold
If the room becomes cooler than expected:
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Check your baby’s chest or neck.
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Add an appropriate clothing layer if your baby actually feels cool.
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Consider a warmer sleep bag suitable for the room temperature.
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Use safe home heating if necessary.
Avoid placing a portable heater directly beside the crib or compensating with loose, heavy bedding.
The thermometer helps you understand the environment, but your baby’s body temperature and comfort are what ultimately guide clothing adjustments.
What to do if the room gets too hot or too cold
How to Tell If Your Baby Is Too Hot or Too Cold
Checking your baby can be more useful than repeatedly adjusting the thermostat.
To check whether your baby is comfortable, feel their chest or the back of their neck, rather than their hands or feet.
Signs your baby may be too hot
Your baby may be too warm if:
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Their chest or neck feels hot.
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Their skin feels sweaty or clammy.
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Their hair or clothing is damp with sweat.
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Their skin appears unusually flushed.
If your baby feels hot, remove one layer or switch to lighter sleepwear.
Signs your baby may be too cold
Cool hands or feet are common and do not necessarily mean your baby is cold. Check their chest or neck instead.
If these areas feel cool, add one light clothing layer or switch to a warmer sleep bag. Avoid loose blankets or multiple heavy layers.
If your baby has a fever or appears unwell, seek appropriate medical advice rather than relying on room-temperature adjustments alone.
Baby Room Temperature in Summer and Winter
Your overnight strategy may need to change with the season.
During hot weather
Keeping the room within 16–20°C may be difficult during summer.
Instead of trying to force the room to an exact number, concentrate on preventing overheating. Use lighter sleepwear, improve safe ventilation, block strong daytime sunlight, and check your baby for signs of being too warm. The Lullaby Trust specifically recommends lighter clothing and bedding when a baby’s room is difficult to cool.
During cold weather
In winter, check how much your baby’s room cools after the heating switches off.
Rather than heavily heating the crib area, aim for a comfortable overall room temperature and choose sleepwear appropriate for the conditions.
A room thermometer is particularly helpful because a room that feels fine at 8 p.m. may be considerably cooler by early morning.
A Simple Overnight Baby Room Temperature Checklist
Before bedtime:
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Check the room temperature with a thermometer.
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Use 16–20°C (61–68°F) as a useful reference range where possible.
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Choose sleepwear for the actual room temperature.
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Consider whether the room normally gets warmer or cooler overnight.
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Keep the crib away from heaters, radiators, air vents, and direct drafts.
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Keep your baby’s head uncovered indoors.
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Keep loose blankets, pillows, toys, and other soft objects out of the sleep space.
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If the room becomes warm, use lighter clothing and improve airflow safely.
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If you are unsure, feel your baby’s chest or the back of their neck.
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Remove a layer if your baby feels hot or sweaty.
FAQ
Is 20°C too hot for a baby’s room?
No. 20°C (68°F) is at the upper end of the 16–20°C range recommended by The Lullaby Trust. Appropriate sleepwear is still important.
Is 22°C too hot for a baby to sleep?
22°C (72°F) is warmer than the commonly recommended 16–20°C range, but the thermometer reading alone does not tell you whether your baby is overheating.
Use lighter sleepwear if necessary and check your baby’s chest or neck for signs of excessive warmth.
Is 18°C too cold for a baby?
18°C (64°F) falls within the commonly recommended range for a baby’s room.
Your baby should still be dressed appropriately for the room.
Should I leave the heating on all night?
Not necessarily.
If the room stays at a comfortable temperature after the heating switches off, there may be no need to keep it running continuously. A room thermometer can help you learn how much the bedroom cools overnight.
Can I use a fan in my baby’s room overnight?
A fan can be used to circulate air in a warm room, but The Lullaby Trust advises against aiming it directly at your baby.
Do I need to check the room temperature during the night?
You generally do not need to repeatedly wake a comfortable baby just to check the temperature.
However, if your home tends to change significantly overnight, you can check the thermometer when you naturally wake and adjust your baby’s clothing if necessary.
Conclusion
Keeping a comfortable baby room temperature overnight does not require maintaining one exact thermostat setting from bedtime until morning.
Use 16–20°C (61–68°F) as a helpful reference range, monitor the room with a thermometer, and think ahead about how the temperature normally changes during the night.
If the room becomes warmer, reduce layers and improve airflow safely. If it becomes cooler, adjust your baby’s sleepwear rather than relying on heavy or loose bedding.
Most importantly, check your baby as well as the thermometer. Feeling their chest or the back of their neck can help you decide whether their clothing is appropriate for the room.
The goal is simple: create a sleep environment that stays comfortably cool, avoids overheating, and requires as little overnight adjustment as possible.
This article provides general educational information and does not replace individualized medical advice from your baby’s healthcare professional.
