What Temperature Should Your Baby's Room Be in Summer?
It is one of those questions that sounds simple until you are standing in your baby's nursery at 11pm with a thermometer in one hand and a fan in the other, wondering if you have got it right. Room temperature is one of the most important factors in safe and comfortable baby sleep, and in summer it is also one of the hardest to control. So let us clear it up properly.
What is the ideal room temperature for a sleeping baby?
The Lullaby Trust recommends that your baby's room is kept between 16 and 20 degrees Celsius, with 18 degrees being the ideal temperature for sleep. This applies all year round, including in summer. The reason this range matters so much is that babies cannot regulate their own body temperature anywhere near as efficiently as adults. They cannot kick off their covers, adjust their clothing or tell you they are uncomfortable. This makes overheating a genuine concern, particularly during warmer months.
What happens if my baby's room is too warm?
A room that is consistently above 20 degrees can affect your baby's sleep quality significantly. Babies sleep lighter and wake more frequently when they are too warm. But beyond sleep disruption, overheating is also a known risk factor in sudden infant death syndrome, which is why the Lullaby Trust guidelines take room temperature so seriously.
If your baby's room is regularly above 20 degrees in summer, it is absolutely worth taking steps to bring it down.
What happens if my baby's room is too cool?
On the flip side, a room that drops below 16 degrees can also cause your baby to wake more frequently as their body works to stay warm. In summer this is less likely to be an issue but on cooler summer nights, particularly in the UK where temperatures can vary enormously, it is worth keeping an eye on.
How do I know what temperature my baby's room is?
A simple room thermometer is one of the most useful things you can have in your baby's nursery. Many baby monitors now include a built in temperature display which is really handy. Place it at the level your baby sleeps rather than high up on a shelf where temperatures can differ.
How to keep your baby's room at the right temperature in summer
Keep curtains and blinds closed during the day
This is one of the most effective things you can do. Direct sunlight streaming through windows heats a room very quickly. Keeping curtains or blinds closed during the hottest part of the day, typically between 11am and 3pm, can make a significant difference to the room temperature by bedtime.Open windows strategically
Once the outside temperature drops below the indoor temperature in the evening, open windows to let cooler air circulate. In the UK this often happens in the early evening, so getting into the habit of opening windows around 6pm or 7pm can really help cool the room before bedtime.Use a fan to circulate air
A fan does not actually cool the air but it does help circulate it and can make the room feel several degrees cooler. Never point a fan directly at your baby. Instead position it to move air around the room and create a gentle breeze. Some parents find placing a bowl of ice in front of the fan helps cool the circulating air further.Consider a portable air conditioning unit
For very hot summers, a portable air conditioning unit can be a worthwhile investment, particularly if your baby's room consistently reaches high temperatures. If you use one, make sure it is not blowing directly onto your baby and check the room temperature regularly to make sure it does not drop too low.Check your baby rather than just the thermometer
The thermometer gives you a reading of the room temperature but the most reliable way to check if your baby is comfortable is to feel the back of their neck or their chest. These should feel warm but not hot or sweaty. If they feel clammy or hot to the touch, your baby needs cooling down regardless of what the thermometer says.
What should my baby wear to sleep based on room temperature?
Here is a simple guide based on the Lullaby Trust recommendations:
At 27 degrees and above, a nappy only is appropriate.
At 25 to 26 degrees, a nappy and light vest.
At 22 to 24 degrees, a nappy, vest and 0.5 tog sleeping bag or light swaddle.
At 20 to 21 degrees, a nappy, vest, sleepsuit and 1 tog sleeping bag.
At 18 to 19 degrees, a nappy, vest, sleepsuit and 2.5 tog sleeping bag.
Always use these as a guide and check your baby regularly, especially during the night when room temperatures can fluctuate.
What if I cannot get my baby's room below 20 degrees?
In a heatwave, even with fans and closed curtains, some rooms simply will not cool down enough. In this situation the most important thing is to dress your baby as lightly as possible and check them regularly throughout the night. A nappy and thin vest is absolutely fine if the room is very warm.
Never be tempted to bring your baby into your bed because you are worried about the heat. This carries its own risks and the Lullaby Trust advises against it. Instead focus on keeping your baby as cool and comfortable as possible in their own sleep space.
When room temperature is affecting your baby's sleep long term
A few warm nights during a heatwave are normal and manageable. But if you find that room temperature issues have triggered a wider sleep disruption that is not resolving once temperatures cool, it might be worth getting some proper support.
As a Norland nanny with 10 years experience, 17 years in childcare altogether and OCN qualified through the Sleep Consultant Academy, summer sleep challenges are something I help families navigate all the time. Whether you need a quick hour to talk things through or a full bespoke sleep plan, I have a level of support to suit every family.
The right room temperature is one piece of the sleep puzzle. But when everything comes together, the difference it makes is remarkable. Let me help you find all the pieces.
Book your free discovery call today and let us get your family sleeping well this summer.
