What Should a 3–6 Month Old Wear to Bed at 23°C?

What makes 23°C a boundary temperature

23°C is the warmest temperature in the 1.0 TOG band — one degree warmer and the recommendation drops to a 0.2 TOG sleeping bag, the lightest option on the Australian market. At 23°C the 1.0 TOG bag is doing full work, but any upward drift overnight pushes toward 0.2 TOG territory. Unlike 22°C, where the room is comfortably within the 1.0 TOG range, at 23°C you're at the edge of it.

For a 3–6 month old, the combination is a long-sleeve bodysuit under a 1.0 TOG sleeping bag. If the room regularly edges above 24°C overnight — which happens in Melbourne's summers when the forecast cool change fails to arrive — switching to a short-sleeve bodysuit under the same bag is a partial adjustment, but the cleaner answer is the 0.2 TOG bag for those warmer nights.

The swaddle note still applies at this age. If your baby has no rolling signs, an arms-free swaddle provides similar warmth to the 1.0 TOG bag at 23°C and is appropriate. But at 23°C in summer, a fitted sleeping bag's ventilation and structured fit is often more practical than a swaddle — and once rolling begins, the bag is the only safe option.

Signs you've got it right (or wrong)

At 23°C, overheating is the more likely problem. Check the chest and back of the neck: warm but not damp is the goal. Damp hair around the hairline, flushed cheeks, or a baby who's restless in the second half of the night — when the room may have warmed further — all point toward the 0.2 TOG bag being the better choice for the following sleep.

In summer conditions, the room thermometer is more reliable than the touch test for deciding whether the bag is right. A room that reads 24°C at midnight means the 1.0 TOG bag is running heavy regardless of how baby feels in the moment — the body is working to dissipate heat before you notice it on the skin. If in doubt, check the thermometer first and the baby second.

Layering for 23°C in an Australian home

In concrete terms: a long-sleeve cotton or bamboo bodysuit under a 1.0 TOG sleeping bag. At 23°C, natural fibres are more important than at cooler temperatures — polyester holds heat, which compounds the problem in a warm room. The ergoPouch 1.0 TOG sleeping bag, the Love to Dream Swaddle UP 1.0 TOG, or a breathable bamboo bodysuit paired with a Bubba Blue 1.0 TOG bag are the right summer combination.

In Melbourne's inner east — Hawthorn, Richmond, Fitzroy, Collingwood — the older brick terraces, California bungalows, and converted Victorian terraces absorb heat through summer days and release it slowly. A 23°C evening reading in January in one of these homes is often the room at its coolest point of the evening: it reached peak temperature in the afternoon and has been giving it back since sunset. The 1.0 TOG combination covers this correctly — and a ceiling fan running to circulate air (not pointed at the cot) helps without the chilling effect of direct airflow.

When room temperature shifts overnight

Melbourne's summer nights have a pattern that doesn't exist anywhere else in Australia: the cool change. A southerly front that drops the temperature by 10–15°C in an hour is common in January and February, and it can arrive anywhere between 8pm and 4am. A 23°C bedroom at 7pm can become an 18°C room by midnight if the cool change arrives — and an 18°C room in a 1.0 TOG bag is on the light side. The Australian Bureau of Meteorology's hourly forecast for the following 24 hours tells you whether a cool change is expected and, roughly, when. Checking it before bed is a genuinely useful habit in Melbourne summer.

If the cool change is expected overnight and the room will likely drop below 20°C, the 2.5 TOG bag is the safer starting point and you can check at midnight. If no cool change is forecast and the room is likely to hold at 23°C or drift warmer, the 1.0 TOG bag is right — and if the room crosses 24°C by the small hours, that's when the 0.2 TOG bag for the following night makes sense. Having both bags accessible in summer is the Melbourne parent's practical answer.

Frequently asked questions

Try a different temperature or age

• What a 3–6 month old should wear at 22°C