Baby Sleep Temperature Chart & Layer Guide in UK

I remember standing in the nursery at 2am, staring at the baby monitor that said 22°C, wondering if that was too warm… or perfectly fine.

If you’ve ever done the same, adjusted the thermostat twice, checked the back of your baby’s neck, then Googled “what temperature should a baby’s room be?” you’re not alone.

Baby sleep temperature feels simple until it’s your baby. Then suddenly every degree matters.

This guide brings everything together clearly:

• The ideal baby sleep temperature in the UK
  

• A practical baby sleep temperature chart
  

• What to dress your baby in at different room temperatures
  

• How to tell if your baby is too hot or too cold
  

• What to do if the room feels too warm or chilly
  

No panic. No extremes. Just calm, evidence-based guidance you can actually use.

What Is the Ideal Baby Sleep Temperature in the UK?

The recommended baby room temperature in the UK is 16–20°C, with around 18°C considered ideal.

This guidance comes from UK safe sleep organisations and the NHS. The reason is simple: overheating increases risk, while slightly cooler is generally safer than too warm.

That doesn’t mean your baby must sleep in exactly 18°C every night. Most homes fluctuate a little. What matters more is:

• Avoiding overheating
  

• Dressing your baby appropriately for the room temperature
  

• Keeping bedding minimal and breathable
  

If your baby’s room sits at 19°C, 20°C or even 21°C, that’s usually perfectly manageable with the right baby clothing layers.

Where parents tend to worry most is 22°C and above, especially during warmer months, we’ll cover that clearly below.

Use a Room Thermometer (And Where to Put It)

It’s surprisingly easy to misjudge room temperature.

Your hallway might feel cool. The nursery might feel stuffy. Radiators and windows can create warm or cold pockets.

If you want peace of mind, use a room thermometer (many baby monitors now include one).

Where to place it:

• At cot height, not near the ceiling
  

• Away from direct sunlight
  

• Away from radiators or heaters
  

• Not directly next to a window
  

If your monitor says 20°C but the room feels warm, check airflow and layering before adjusting heating. Babies regulate temperature less efficiently than adults, so small changes matter more for them than they do for us.

Baby Sleep Temperature Chart (Room Temperature & What to Wear)

This is the part most parents search for: a clear baby sleep temperature chart.

Below is a practical UK-based guide using Celsius.

Room Temperature	What Baby Can Wear	Notes
24–27°C	Nappy only or short-sleeve bodysuit + 0.5 tog sleeping bag	Very warm room
22–24°C	Short-sleeve bodysuit + 1.0 tog sleeping bag	Warm room
20–22°C	Short- or long-sleeve bodysuit + 2.5 tog sleeping bag	Comfortable range
18–20°C	Long-sleeve bodysuit n+ sleepsuit + 2.5 tog sleeping bag	Ideal UK range
16–18°C	Long-sleeve bodysuit + sleepsuit + 2.5 tog sleeping bag	Ideal cooler range
14–16°C	Long-sleeve bodysuit + sleepsuit + 3.5 tog sleeping bag	Cold room
Under 14°C	Long-sleeve bodysuit + sleepsuit + 3.5 tog sleeping bag + socks	Very cold room

A few gentle reminders:

• Always adjust based on how your baby feels, not just the number.
  

• Check the back of the neck or chest, not hands or feet (they’re usually cooler).
  

• Layering works better than thick single items.
  

• Breathable fabrics matter more than heavy synthetic ones.
  

If you’d like a deeper breakdown of how to layer safely at night, I’ve written more about it in our guide to how to dress your baby for sleep.

How to Dress a Baby for Sleep at Different Temperatures

The temperature chart above gives a snapshot, but real life isn’t always that tidy.

Some nights start at 21°C and drop to 17°C by 4am. Some nurseries hold heat more than the rest of the house. And some babies naturally run warmer than others.

So here’s a more detailed look at what to dress your baby for sleep in depending on the room temperature.

16–18°C (Cool Room)

This is actually within the recommended ideal range in the UK.

You can dress your baby in:

• A long-sleeve organic baby bodysuit
  

• A sleepsuit
  

• A 2.5 tog sleeping bag
  

If you’re using breathable fabrics like our organic baby nightwear, layering works beautifully because it traps warmth without overheating.

A cool room is usually safer than a warm one, as long as baby is dressed appropriately.

 

19–21°C (Ideal Range)

This is where most UK nurseries sit.

You might use:

• A short- or long-sleeve bodysuit
  

• A sleepsuit
  

• A 2.5 tog sleeping bag
  

At 20°C, many babies are perfectly comfortable in a long-sleeve bodysuit and a sleeping bag without a thick sleepsuit underneath.

This is where knowing your baby matters. Some run warm. Some feel cooler.

If you’re unsure, check the back of their neck after they’ve been asleep for 15–20 minutes.

 

22–23°C (Slightly Warm)

This is where parents start asking: Is 22 degrees too hot for a baby room?

It isn’t automatically unsafe, but you do need to reduce layers.

Read also: How many layers should baby wear

You could dress your baby in:

• A short-sleeve bodysuit
  

• A 1 tog or 2.5 tog sleeping bag (depending on the baby and fabric breathability)
  

Avoid thick fleece sleepsuits at this temperature.

Light, breathable layers are better than one heavy piece. Our guide on how many layers should a baby wear? explains layering in more detail if you’d like extra reassurance.

24–25°C (Warm Night)

This is common in UK heatwaves or well-insulated homes.

At 24–25°C:

• A short-sleeve bodysuit with a 0.5–1 tog sleeping bag is usually enough
  

• Or sometimes just a lightweight sleepsuit
  

At 25°C and above, many babies are comfortable in:

• A nappy and a lightweight sleeping bag
  

You can find more practical tips for very warm nights in our post on organic baby clothes for heatwaves and hot nights, especially if you’re navigating summer sleep for the first time.

 

26°C and Above (Hot Night)

If your baby’s room is 26°C or higher:

• A nappy alone may be enough
  

• Skip the sleeping bag if needed
  

• Focus on airflow rather than layering
  

We’ll cover what to do if the room is too warm in more detail below.

 

How to Check If Your Baby Is Too Hot or Too Cold

The simplest method is still the most reliable:

Feel the back of your baby’s neck or their chest.

Not hands.
Not feet.

Babies often have cool hands and feet, that’s normal.

If their neck feels:

• Warm and slightly sweaty → remove a layer
  

• Cool but comfortable → they’re likely fine
  

• Cold to the touch → consider adding a light layer
  

You can also listen to their breathing. Rapid breathing, flushed cheeks, or damp hair can be signs of overheating.

Signs Baby Is Too Hot While Sleeping

Overheating is something we want to avoid.

Signs baby may be too hot:

• Sweaty neck or back
  

• Damp hair
  

• Flushed cheeks
  

• Rapid breathing
  

• Restlessness
  

If you notice these:

• Remove a layer
  

• Lower the room temperature if possible
  

• Increase airflow safely
  

How to Tell If Baby Is Too Cold at Night

Cold babies are usually easier to read than we expect.

Signs baby may be too cold:

• Cool chest and back
  

• Pale skin
  

• Waking more than usual
  

• Slight shivering (rare in newborns but possible)
  

If baby feels cool:

• Add a lightweight layer
  

• Adjust sleeping bag tog
  

• Check for drafts near the cot
  

Many parents worry about what happens if baby is too cold at night. In most UK homes, babies are more at risk of overheating than becoming dangerously cold, but comfort still matters for good sleep.

Does Baby Sleep Temperature Differ Between Boys and Girls?

A common question parents ask is whether boys and girls need different room temperatures or dressing approaches for sleep. The short answer is no, the recommended baby sleep temperature range of 16–20°C (61–68°F) applies equally to all babies, regardless of sex.

While individual babies may naturally run a little cooler or warmer, these differences are personal rather than gender‑based. What matters most is observing how your baby feels, not their gender:

• Check the back of the neck or chest, this is the most reliable way to judge comfort.

• Adjust layers and sleeping bag TOG based on room temperature.

• Watch for signs of overheating (sweaty, flushed, restless) or being too cold (cool chest/back, pale skin).

In other words, focus on your baby’s cues and comfort rather than whether they’re a boy or a girl, the same safe sleep temperature and layering guidance works for everyone.

🛍️ For comfortable, season‑appropriate outfits:

Dress your baby in gentle, breathable layers that suit the room temperature, whether it’s cool nights or warmer days:

👉 Shop organic baby boy clothes

👉 Explore soft, comfy baby girls clothes

 

Our Bedclothes & Bedding Rules (What to Avoid in the Cot)

Room temperature matters, but so does what’s inside the cot.

For safe sleep:

• Keep the cot clear of pillows, loose blankets and toys
  

• Avoid heavy duvets
  

• Use a well-fitting mattress
  

• If using a blanket, tuck it in firmly at the bottom (feet-to-foot position)
  

Sleeping bags are popular because they reduce the risk of loose bedding moving over baby’s face.

Avoid layering thick blankets over a sleeping bag. Overheating often happens because of too much bedding, not just room temperature.

What To Do If Baby’s Room Is Too Warm

Warm nights happen , especially in summer, top-floor bedrooms, or well-insulated homes.

If your baby’s room is above 22–23°C:

• Reduce clothing layers
  

• Switch to a lower tog sleeping bag
  

• Open windows earlier in the evening to release trapped heat
  

• Close curtains before sunset to reduce heat build-up
  

• Use a fan to circulate air (not blowing directly on baby)
  

If you’re using a fan in the baby’s room, position it away from the cot and use it to move air around the room rather than directly at your baby.

If the temperature reaches 25°C or above:

• Dress baby minimally
  

• Consider nappy-only sleep
  

• Skip the sleeping bag if necessary
  

If you’re unsure how to adjust clothing safely in warm weather, our detailed guide on how to dress your baby for sleep walks through real-life examples by temperature.

What To Do If Baby’s Room Is Too Cold

Cold nurseries are more common in older UK homes, especially in winter.

If the room drops below 16°C:

• Add a long-sleeve bodysuit
  

• Increase sleeping bag tog
  

• Check for drafts near windows or doors
  

• Warm the room before bedtime rather than layering heavily inside the cot
  

Avoid:

• Hot water bottles
  

• Electric blankets
  

• Thick duvets
  

Warm the room, not the bedding.

If you’re preparing for colder months, our practical advice in the complete guide to dressing your baby for every UK season can help you plan ahead.

 

Is 22 Degrees Too Hot for a Baby Room?

Short answer: No, 22°C is not automatically too hot.

It’s slightly above the recommended ideal range, but with lighter clothing and good airflow, it’s usually manageable.

Monitor how your baby feels rather than focusing on the number alone.

Is 25 Degrees Too Hot for a Baby Room?

Short answer: 25°C is warm and requires minimal clothing.

At this temperature:

• Avoid layering
  

• Use lightweight sleepwear or just a nappy
  

• Increase airflow safely
  

If the room remains above 26°C for prolonged periods, focus on ventilation and keeping your baby lightly dressed.

 

Should Newborns Sleep in a Hat?

This question comes up often.

In most cases, newborns should not sleep in a hat indoors.

Babies release heat through their heads. Covering the head while sleeping indoors can increase the risk of overheating.

Hats are useful outdoors in cold weather, but not usually necessary inside a temperature-controlled room.

If you’re preparing winter outfits, our collection of organic baby beanie hats is designed for outdoor warmth, not for night-time sleep.

 

The Benefit of Sharing a Room With Your Baby

In the early months, room-sharing is often recommended.

Having your baby sleep in the same room (but in their own sleep space) makes it easier to:

• Monitor temperature
  

• Respond quickly
  

• Adjust layers if needed
  

It also reduces the risk of certain sleep-related issues in the first six months.

If you’re room-sharing, just make sure your baby’s cot isn’t positioned next to:

• Radiators
  

• Heaters
  

• Direct sunlight
  

• Drafty windows
  

Even a few degrees difference can matter.

Does Room Temperature Affect SIDS Risk?

Overheating is associated with increased sleep risk.

That’s why UK guidance focuses on:

• Avoiding heavy bedding
  

• Keeping the cot clear
  

• Maintaining a moderate room temperature
  

• Dressing baby appropriately
  

Room temperature alone doesn’t cause problems, but overheating combined with heavy bedding or over-layering can increase risk.

Keeping things simple, breathable and uncluttered is usually safest.

 

What Is a Normal Temperature for a Baby?

Separate from room temperature, parents often worry about body temperature.

A normal newborn temperature is usually around:

36.5°C to 37.5°C

If your baby’s temperature is:

• Above 38°C → seek medical advice
  

• Below 36°C → warm gently and monitor
  

If you’re unsure how to check safely, use a digital thermometer and follow NHS guidance.

Room temperature and body temperature are related, but not the same thing.

When Can Babies Regulate Their Temperature Better?

Newborns cannot regulate temperature as efficiently as older babies or adults.

In the first few months, they rely on:

• Proper clothing
  

• Stable room temperature
  

• Caregiver adjustments
  

By around 11–12 weeks, babies become slightly better at regulating their body temperature, but they still need appropriate layering.

Baby Sleep Temperature in Winter vs Summer (UK Homes)

UK homes aren’t consistent.

In winter:

• Radiators can overheat small rooms
  

• Night temperatures drop sharply
  

• Drafts are common
  

In summer:

• Top-floor bedrooms trap heat
  

• Evening cooling may be slow
  

• Insulated homes hold warmth overnight
  

A baby room thermometer helps, but your awareness matters too.

If you’re setting up a nursery from scratch, our post on eco-friendly baby nursery ideas (UK) touches on airflow and comfort as part of creating a safe sleep space.

🛍️ Shop seasonal baby clothing:

• Keep your little one warm with organic baby winter clothes

• Stay cool in summer with organic summer clothes for babies and kids

 

Why Fabric Matters: Breathability and Temperature

Not all fabrics respond to temperature the same way.

Heavy synthetic fabrics can trap heat. Breathable cotton allows airflow and helps regulate warmth.

That’s one reason I personally lean toward breathable organic cotton layers at night, they’re gentle on skin and less likely to cause overheating than thick fleece.

If you’re curious about the science behind it, we’ve written more about the benefits of organic cotton baby clothes, especially in relation to comfort and temperature regulation.

Layering lighter breathable pieces usually works better than relying on one thick item.

Baby Sleep Temperature - Frequently Asked Questions

What temperature should a baby sleep in the UK?

Is 25 degrees too hot for a baby room?

Yes, 25°C is generally considered too warm for a baby’s room and sits above the recommended 16–20°C range (with 18°C ideal). While 22°C can often be managed with lighter layers, 25°C increases the risk of overheating, which is linked to SIDS. Extra care with clothing and airflow is important.

If the room is 25°C:

• Dress lightly: 0.5–1.0 tog or just a bodysuit/nappy

• Improve airflow: Use a fan (not directly on baby)

• Block heat: Close curtains in the day, open windows at night

• Use a thermometer: Monitor room temperature

Signs of overheating:

• Hot or clammy chest/neck

• Sweating

• Remove a layer if needed

Is 22 degrees too hot for a baby room?

Is it OK for a baby to sleep in a cold room?

How do I know if my baby is too cold at night?

What is a normal temperature for a newborn?

Should newborns sleep in a hat?

What is the 5-3-3 rule for babies?

 

Is 2.5 tog warm enough for a baby?

Yes, a 2.5 TOG sleeping bag is usually considered ideal and sufficiently warm for a baby, suitable for year-round use in typical room temperatures (around 18–21°C / 64–70°F). It’s a versatile choice for cooler nights in autumn, winter, or spring and is often worn over a long-sleeved bodysuit and pyjamas.

What is the room temperature linked to SIDS risk?

There isn’t a single temperature that causes risk. To help lower the risk of Sudden Infant Death Syndrome (SIDS), a safe room temperature for a sleeping baby is 16–20°C (61–68°F). Overheating is a major risk, so it’s important to keep the room cool and dress the baby appropriately, using light bedding or a sleep sack.

What’s the coldest temperature a baby can sleep in?

There isn’t a strict minimum, but rooms below 16°C may require extra layering. Rather than focusing on a number alone, ensure your baby’s chest feels comfortably warm and that they are dressed appropriately.

Final Thoughts: Getting It Right Without Overthinking It

Baby sleep temperature can feel like something you need to get exactly perfect.

But in reality, it’s about balance.

• A room between 16–20°C.
• Breathable layers.
• A clear cot.
• A quick neck check if you’re unsure.

You don’t need to chase a precise number every night.

UK homes change with the seasons. Radiators switch on. Heatwaves arrive unexpectedly. What matters is paying attention, adjusting gently, and trusting your instincts alongside evidence-based guidance.

If you’d like more support on layering safely and comfortably, you can explore:

• Our detailed guide on how to dress your baby for sleep
  

• Seasonal advice in the complete guide to dressing your baby for every UK season
  

• And shop our organic baby sleepwear for every season
  

Sleep can feel fragile in those early months. Temperature is just one piece of the puzzle, and once you understand it, it becomes much less intimidating.

You’re doing better than you think.