Helping your baby sleep in hot weather: a calm summer guide

Hot weather can undo a good sleeper overnight. A room that felt cosy in spring turns stuffy by July, and a baby who used to settle in minutes starts squirming, waking and generally letting you know they’re too warm. The good news: a few small summer changes make a real difference, and none of them mean bending the safe-sleep rules.

Keep the room cool

The single biggest lever is the room itself. During the day, close blinds and curtains on the sunny side to stop the space turning into an oven, then open up in the evening to let cooler air through. A cool, comfortable nursery is often recommended around 16–20°C (about 68–72°F) — treat that as a guide, not a hard rule. On a heatwave night you may not hit it, and that’s okay; do what you can to bring the temperature down.

A fan helps, but keep it off to the side or pointed at a wall to circulate air rather than blowing straight onto your baby. The cot stays clear, with no draught directly over it.

Dress lighter, not heavier

In the heat, the instinct to bundle up works against you. Swap the vest-plus-pyjamas combo for lighter layers — a short-sleeved cotton bodysuit, or on the hottest nights just a nappy under a low-tog sleep sack (a 0.5 tog is made for exactly this).

Crucially, warm weather changes what you take off, never what you add. Do not add loose blankets to the cot to “even things out.” No blankets, pillows or soft toys — baby sleeps on their back on a firm, clear surface, summer and winter alike. If you want a quick gut-check, feel the chest or back of the neck: warm is fine, sweaty means overdressed.

Offer more feeds and fluids

Heat makes little ones thirstier. Breastfed babies may want to nurse more often and for shorter stretches — follow their lead and feed on demand. Formula-fed babies may take smaller, more frequent bottles. Keep the bedtime feed calm and unhurried, and put your baby down drowsy but still awake. If your baby is over six months, your doctor may suggest small sips of water with meals; check with them first.

Manage the light

Long summer evenings send a wake-up signal exactly when you want a wind-down one. Pre-cool and darken the room an hour or so before bed by dropping the blinds against the low sun, then crack a window afterwards to ventilate without letting light flood back in. A darker room reads as “night” to your baby’s body clock, even at 8 p.m. in July.

Adjust your expectations on hot nights

Even with everything dialled in, some hot nights are just harder — more stirring, more brief wakings. That’s normal, not a sign you’ve done something wrong. This is also where timing earns its keep: an overheated baby fights sleep, and so does an overtired one, so getting the day’s rhythm right matters more than usual. If you’re not sure how long your little one should be awake between sleeps, our guide to wake windows by age is a good starting point.

Keeping track of naps and timing in a heat-scrambled week is genuinely hard to hold in your head. That’s the kind of thing Nana quietly does for you — you log a sleep with one tap and it learns your baby’s real rhythm, so you can put your energy into the cool room and the calm feed instead of the mental math.

Every baby is different, and none of this replaces your pediatrician. Room-temperature ranges here reflect widely cited comfort guidance, not a medical rule; safe-sleep basics always come first. If your baby seems unwell in the heat, or something feels off, ask your doctor.