The safest room temperature for a baby to sleep in is 18–22°C, according to Red Nose Australia. and overheating is a known risk factor for SIDS. This is why room temperature matters as much as safe sleep position. Australian homes, with their wide temperature swings from tropical summers to freezing winter nights, make getting the room temperature right both important and challenging.
This guide covers how to check your baby's temperature, which TOG rating to choose by season, and exactly how to dress your baby for sleep at every age and temperature. We also cover heaters, fans, room thermometers, and the signs your baby is too hot or too cold.
Red Nose Australia recommends 18–22°C as the safe room temperature range for baby sleep. This range balances warmth with the reduced SIDS risk associated with cooler temperatures. Babies cannot regulate their body temperature as well as adults, they overheat faster and lose heat faster.
The rule of thumb: If you're comfortable in light clothing, your baby probably is too. If you feel cold, your baby likely needs an extra layer. Always use a room thermometer. not guesswork; to know the actual temperature.
The risks at each extreme are different. Below 16°C, a baby can get too cold, which increases the risk of respiratory infections. Above 24°C, overheating becomes a serious concern, and overheating is a known SIDS risk factor. Most Australian homes without climate control swing between these extremes across seasons, which is why dressing your baby appropriately matters.
The back of the neck (or the tummy) is the most reliable place to check your baby's temperature. Hands and feet are naturally cooler and are not a reliable indicator.
Signs your baby is too hot:
Signs your baby is too cold:
If your baby is too hot, remove a layer and wait 5–10 minutes before checking again. If too cold, add a layer (a singlet under the sleeping bag, or a warmer TOG). Red Nose advises against using a hat for sleep — babies release excess heat through their head.
TOG (Thermal Overall Grade) tells you how warm a sleeping bag or sleep sack is. Higher TOG = warmer. The table below maps TOG ratings to room temperatures for Australian conditions:
| Room Temp | TOG | What to Wear Underneath | AU Season Example |
|---|---|---|---|
| 26°C+ | 0.2 or none | Nappy only | Summer heatwave (Darwin, Brisbane) |
| 24–26°C | 0.2 TOG | Short-sleeve singlet | Warm summer night |
| 22–24°C | 0.5 TOG | Short-sleeve bodysuit | Spring/autumn evening |
| 20–22°C | 1.0 TOG | Long-sleeve bodysuit | Mild Sydney winter |
| 18–20°C | 2.5 TOG | Bodysuit + lightweight pyjamas | Melbourne winter |
| 16–18°C | 2.5 TOG | Bodysuit + warm pyjamas + singlet | Cold winter night |
| Below 16°C | 3.5 TOG | Bodysuit + fleece pyjamas + singlet | Tasmania, Canberra winter |
For a deeper dive into sleeping bags, see our baby sleeping bags guide with detailed sizing and safety information.
Newborns can't regulate their temperature well. In a room at 20–22°C, dress your newborn in a singlet, a long-sleeve bodysuit, and a swaddle or 1.0 TOG sleeping bag. Check their neck every time you check on them. Newborns should never wear a hat to sleep.
By this age, your baby has likely transitioned from a swaddle to a sleeping bag with arms free. For 20–22°C, a 1.0 TOG bag over a long-sleeve bodysuit works for most babies. For colder rooms, layer a singlet underneath and move up to 2.5 TOG. Watch for the first signs of rolling and stop swaddling immediately when you see them.
Your baby is more active and moving around the cot. A 2.5 TOG sleeping bag is the workhorse for most Australian babies through autumn, winter, and spring. Dress in a bodysuit plus lightweight pyjamas underneath. In summer, a 0.5 TOG bag with a short-sleeve bodysuit is usually enough.
Australian winter nights can drop well below the recommended 18°C minimum in many homes, particularly older houses without central heating. Dressing your baby properly becomes essential.
Winter dressing strategy (room 14–18°C):
If using a heater, set the thermostat to 18–20°C and place it at least one metre from the cot. Oil column heaters are the safest option for nurseries — they don't have exposed elements and maintain a steady temperature. Never use a portable gas heater in a baby's room; they produce carbon monoxide.
Red Nose winter safety: Do not use hot water bottles, electric blankets, or wheat bags in your baby's cot. They can overheat a baby rapidly and are not recommended under Red Nose safe sleep guidelines.
Overheating is a bigger risk than being slightly cool, particularly in Australian summer. When the temperature climbs above 24°C in the nursery, take these steps:
A lukewarm bath before bed can help lower your baby's body temperature on a hot evening. Avoid cold baths, which can shock a baby's system.
A room thermometer is a small investment that takes the guesswork out of dressing your baby. Many parents rely on how the room feels to them, but what feels warm to an adult in pyjamas can feel very different to a baby in a sleeping bag. A basic digital room thermometer costs around AU$10–15 and gives you an objective reading every time.
Some baby monitors include a room temperature sensor, which is convenient. If you're using one, place the sensor near the cot at mattress level — not near a window or heater where the reading will be inaccurate.
Our reviewed picks include TOG-rated sleep sacks for every Australian season — from 0.2 TOG summer bags to 3.5 TOG winter warmth.
See Best Sleep Sacks →Red Nose Australia recommends keeping your baby's room between 18–22°C year-round. In winter, this often means using a heater with a thermostat. Avoid overheating — a room above 22°C increases SIDS risk. Use a room thermometer to check, not guess.
Check the back of your baby's neck or their tummy — not their hands or feet, which are naturally cooler. A cold neck or tummy means they need another layer. A sweaty or hot neck means they're overdressed. Red Nose advises that babies should feel comfortably warm, not hot to the touch.
Yes, if the room temperature exceeds 25°C. In an Australian summer heatwave with no air conditioning, a nappy and a 0.2 TOG sleeping bag (or no bag) are appropriate. Watch for signs of overheating — flushed cheeks, rapid breathing, damp hair. A fan circulating air (not blowing directly on the baby) helps.
For a room temperature of 22°C, use a 1.0 TOG sleeping bag with a short-sleeve bodysuit underneath. If your baby tends to feel warm, a 0.5 TOG bag is also suitable. Always check your baby's neck to confirm they're comfortable — TOG guides are starting points, not rules.
Only if the room regularly drops below 16°C. If using a heater, choose one with a thermostat set to 18–20°C, place it at least one metre from the cot, and never use it to heat the cot directly. Oil column heaters are generally the safest option for nurseries. Never use portable gas heaters — they produce carbon monoxide.
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