The ideal temperature for a baby’s room is between 68°F and 72°F (20°C to 22°C). While the American Academy of Pediatrics doesn’t specify an exact number, this range is widely recommended by pediatricians and children’s health organizations as the safest zone for infant sleep.
Why Babies Need a Cooler Room
Babies are far less efficient at regulating their own body temperature than adults. They have a much larger surface area relative to their body weight, which means they lose and gain heat faster. Newborns rely heavily on a special type of fat tissue that generates warmth without shivering, but this system is still developing in the early months of life. The result: babies can overheat or get too cold quickly, often without obvious warning signs.
This is why room temperature matters more for infants than it does for older children or adults. A room that feels perfectly comfortable to you might be too warm for your baby, especially if they’re swaddled or wearing a sleep sack.
Overheating and SIDS Risk
The most important reason to keep the nursery in that 68°F to 72°F range is safety. Overheating during sleep increases a baby’s risk of sudden infant death syndrome (SIDS). The Mayo Clinic lists being too warm while sleeping as a known risk factor.
To reduce this risk, avoid heavy blankets in the crib entirely. Use a sleep sack or dress your baby in light layers instead. Never cover your baby’s head while they sleep. Running a ceiling fan or providing gentle air circulation in the room has also been linked to lower SIDS risk, likely because it helps prevent pockets of stale, warm air from forming around the baby’s face.
How to Dress Your Baby for the Room Temperature
Sleep sacks and swaddles are rated using a system called TOG, which measures thermal resistance. The higher the TOG number, the warmer the garment. Matching the TOG rating to your room temperature keeps your baby comfortable without extra blankets.
- 75°F to 81°F: Use a 0.2 TOG sleep sack (very lightweight, almost like a single layer of cotton)
- 68°F to 75°F: Use a 1.0 TOG sleep sack
- 64°F to 72°F: Use a 1.5 TOG sleep sack
- 61°F to 68°F: Use a 2.5 TOG sleep sack
- Below 61°F: Use a 3.5 TOG sleep sack (the warmest option)
A good baseline for most nurseries in the 68°F to 72°F range is a 1.0 TOG sleep sack over a short-sleeve onesie. If the room runs cooler, add a long-sleeve layer underneath or move up to a 1.5 or 2.5 TOG sack. If the room is warmer, dress your baby in just a diaper with a lightweight 0.2 TOG sack, or skip the sack altogether.
Signs Your Baby Is Too Hot or Too Cold
A room thermometer is the easiest way to monitor the nursery, but your baby’s body gives you direct feedback too. Touch the back of their neck or their chest (not their hands or feet, which tend to run cool naturally). The skin there should feel warm but not hot or sweaty.
Signs of overheating include flushed or red skin, sweating, damp hair, fussiness, restlessness, or unusual sluggishness. A rapid heartbeat or skin that feels hot to the touch also signals that your baby is too warm. In more serious cases, a baby may appear weak, confused, or nauseous. If you notice these signs, remove a layer, move them to a cooler spot, and check on them frequently.
A baby who is too cold will typically feel cool on the chest or back and may be fussy or have slightly bluish hands and feet. Adding a layer or increasing the room temperature by a couple of degrees usually resolves this quickly.
Humidity Matters Too
Temperature is only part of the equation. The humidity in your baby’s room should stay between 35% and 50%, according to Boston Children’s Hospital. Air that’s too dry can irritate your baby’s airways and cause coughing. Air that’s too humid encourages the growth of dust mites, mold, and other allergens, which can also trigger coughing and breathing difficulty.
A simple hygrometer (often built into digital room thermometers) lets you track both temperature and humidity at a glance. If your home runs dry in winter, a cool-mist humidifier can bring levels up. If humidity climbs above 50% in summer, air conditioning or a dehumidifier will bring it back down.
Practical Tips for Maintaining the Right Temperature
Set your thermostat to 68°F to 72°F at night during sleep. If you don’t have central air, a portable fan or window unit can help in warmer months. Position the crib away from direct sunlight, heating vents, radiators, and exterior walls, all of which can create temperature swings that your room thermometer in another corner won’t catch.
In older homes where temperature control is inconsistent, placing a thermometer right next to the crib gives you the most accurate reading. Check it before bedtime and again during any nighttime wake-ups, especially during seasonal transitions when outdoor temperatures shift dramatically overnight. Adjusting your baby’s clothing layer by layer is usually more effective than constantly changing the thermostat.