By Roy Newlan, founder Last updated 18/08/2026
What temperature should the bedroom be?
Sleep researchers commonly suggest somewhere around 17 to 19 degrees Celsius for most adults. Cooler than most living rooms, and cooler than most people expect.
The exact number matters less than the direction. A bedroom that runs cool beats one that runs warm, almost every night of the year.
Why a cool room helps
Your core body temperature has to drop a degree or so before you fall asleep, and it stays low through the night. That drop is one of the signals your body uses to start the night, and a cool room helps it along. A warm room fights it.
The bigger cost comes later. Overheating is a classic driver of the restless second half: you fall asleep fine, then spend the small hours kicking off the doona, surfacing between sleep cycles, and waking properly around 3am. The room didn't stop you getting to sleep. It stopped you staying there.
The good news is temperature is one of the easiest sleep levers to pull. You don't have to change your habits or your head. You change the room.
Getting there in an Australian bedroom
Seventeen to nineteen degrees is easy to write and harder to hit in a Sydney January. Here's the practical version, season by season.
| Season | Without aircon | With aircon or heating |
|---|---|---|
| Summer | Windows open once the outside air cools, blinds closed through the day, a fan aimed across the bed, the lightest sheet you own | Set 18 to 20 degrees, run it for the hour before bed, then let the fan carry it |
| Autumn and spring | Usually the easy months, crack a window and let the night do the work | Rarely needed, resist the urge to warm the room "to be comfortable" |
| Winter | Warm bedding, cool air: heavier doona, warm sleepwear, room stays cold | Heat the living room, not the bedroom, and switch heating off before bed |
A few of these earn a closer look.
A fan does more than aircon gets credit for. Moving air pulls heat off your skin even when the room itself is warm. On most summer nights a fan across the bed gets you most of what aircon offers, for a fraction of the running cost, with no 2am temperature argument.
Cool the sleeper, not just the room. Light natural-fibre sheets, one layer you can kick off, and no heavy doona out of habit. In winter, flip it: the room stays cold and the bedding does the warming. A cold room under a warm doona is close to ideal.
The warm shower trick. A warm shower before a cool bedroom sounds backwards and works well. The warm water pulls blood to your skin, and when you step out into a cooler room your core temperature drops faster than it would have on its own. It's the same drop your body was going to do anyway, given a head start. More on the body side of the wind-down here.
Close the blinds at lunchtime, not bedtime. In summer the bedroom heats up through the afternoon. Blocking the sun at midday keeps degrees out of the room that no fan can remove at 10pm.
Where the cold drink fits
Temperature is one lever in a wider wind-down, and it pairs naturally with the last step of ours. One scoop of Settl in a glass of cold water, 30 to 60 minutes before bed. A cold drink at the end of a warm evening fits the direction your body is already heading, and the electrolyte base means you go to bed hydrated without a bathroom trip booked for 2am.
It's one piece of the routine, not the whole routine. The full picture, room, light, timing and the rest, is in the wind-down guide.
Cool room, warm bedding, cold drink. The night takes care of the rest.
Cheers, Roy