Getting a good night’s sleep is dependent on a range of factors, from the quality of your mattress to the amount of light visible in your bedroom. Something that we often overlook is temperature, which plays a vital role in sleep health.
Experts agree that most adults sleep best in a cool room, ideally between 16°C and 19°C (often closer to 18–19°C), as this promotes deeper, more restorative rest. Ensuring the right sleep temperature can be difficult, especially with Australia’s changing seasons and diverse climates.
In this guide, we explore the science of cooler sleep environments and why they promote deeper, more restful sleep. We examine how temperature needs vary across different age groups, and offer practical strategies for crafting a sleep-friendly bedroom. You’ll also find expert tips for adapting to seasonal changes — plus, discover how a premium mattress can help regulate body temperature for year-round comfort.
Finding the right sleep temperature
In Australia, we have a vast and varied climate, from humid summers to chilly winters. Keeping your bedroom at the right temperature can be tricky, especially in warmer months. But experts consistently recommend an ideal sleep temperature for adults of 16°C to 19°C.
This cool range helps your body lower its core temperature in the evening — a natural part of preparing for restful sleep. And considering that around one in three Australians reports waking up in the middle of the night due to the heat, making simple adjustments like temperature control can make a big difference to our overall sleep quality.
It’s worth remembering that every person’s comfort level is different. Rather than sticking to a specific temperature, it is more important to understand how your body responds and create a sleep space that allows your internal temperature to settle into its natural rhythm.
Why cooler temperatures promote better sleep
Your core body temperature naturally begins to drop during the evening. This process, called thermoregulation, is tied to your circadian rhythm or sleep cycle and helps to trigger sleep.
A bedroom that is too warm can interfere with this process, making it harder to fall and stay asleep. You may find yourself tossing and turning, sweating, or waking throughout the night. On the other hand, a cold bedroom may lead to discomfort or shivering, resulting in light sleep that is neither comfortable nor restful.
A slightly cool room, however, helps signal your brain that it’s time to rest, setting the stage for deeper, more restorative sleep. When the temperature is just right, your body can relax more easily: muscles release tension, your heart rate slows, and sleep onset occurs faster.
Sleep temperatures by age & stage
Everyone’s ideal sleep temperature varies slightly depending on factors like age, hormonal changes, and sensitivity to heat or cold. What feels comfortable for one person might disrupt sleep for another, so it’s important to understand how different life stages influence comfort at night.
| Age range | Ideal temperature (Celsius) | Ideal temperature (Fahrenheit) |
|---|---|---|
|
Infants |
16–20 °C |
60.8–68 °F |
|
Adults |
18–19 °C |
64.4–66.2 °F |
|
Older adults |
20–25 °C |
68–77 °F |
Infants
Babies are sensitive to temperature and more prone to overheating, as they do not begin to thermoregulate until 6–18 weeks. It is generally advisable to keep the nursery between 16–20°C. To maintain a safe and comfortable environment, use breathable fabrics, avoid heavy blankets or coverings, and always follow safe sleep guidelines.
Watch for signs that your baby may be too warm, such as flushed skin, sweating, or rapid breathing. In addition to temperature, good airflow is essential in warmer months — a gentle fan can help circulate air without overcooling the room.
Adults
For most adults, the ideal sleep temperature is between 16–19°C, with many people claiming that their “sweet spot” is 18–19 °C. Hormonal changes and individual metabolic differences can cause many people to feel warmer at night. A slightly cooler room, combined with breathable sleepwear and moisture-wicking sheets, can help maintain consistent comfort.
For those experiencing hot flashes, night sweats, or general overheating, temperature regulation becomes especially important. Cooling solutions like gel-infused pillows or temperature-sensitive bedding can offer added relief by drawing excess heat away from the body and promoting a more restful sleep.
Older adults
As we age, sensitivity to cold can increase. While 19–21°C is generally recommended as an ideal sleep temperature, some older adults may be more comfortable with a range of 20–25°C. Layering bedding and choosing warmer pyjamas can help maintain comfort without overheating the room or impacting sleep cycles.
Tips for creating a sleep-friendly bedroom
Creating the ideal sleep environment often begins with adjusting your thermostat or air conditioning, but there are plenty of other ways to manage temperature and support uninterrupted rest, even when direct climate control isn’t an option. From smart bedding choices to airflow strategies, small changes can make a big difference.
- Use blackout curtains — reduce heat and block early morning light
- Take a warm shower before bed — this encourages your body to cool down naturally
- Keep air flowing — open windows for a breeze, use ceiling or pedestal fans, or opt for air-conditioning
- Choose breathable bedding — cotton or bamboo sheets wick moisture and allow airflow
- Pick the right mattress — Sealy’s Posturepedic range includes materials designed for temperature regulation, like moisture-wicking fabrics and gel-infused comfort layers
- Avoid synthetic sleepwear — choose organic and lightweight fabrics that help regulate heat
- Layer bedding rather than relying on a heavy doona — this offers flexibility throughout the night
- Keep electronics out of bed — screens and chargers can generate heat and disrupt circadian rhythms with their light
Seasonal adjustments in summer and winter
Australia’s climate shifts significantly throughout the year, with hot, humid summers in some regions and cold, dry winters in others. Adapting your sleep setup to suit these seasonal changes is key to staying comfortable and ensuring consistent, quality rest year-round.
Staying cool in summer
To keep your bedroom cool during the warmer months, start by closing blinds or curtains during the day to block out heat from the sun. At night, switch to lightweight, breathable bedding and pyjamas made from natural fabrics like cotton or bamboo, which help wick away moisture and allow better airflow. Some families find it useful to have summer and winter sets of bedding, with lightweight doonas or sheets that get swapped out as the weather changes.
Create cross-ventilation by opening windows where it’s safe to do so. Pedestal or ceiling fans can help maintain steady airflow while you sleep, with air conditioning set between 18–20°C where possible.
Keeping cosy in winter
During colder months, creating a warm and comfortable sleep environment starts with thoughtful layering. Instead of relying on a single thick doona, layer blankets so you can adjust warmth throughout the night. Opt for flannel or thermal sheets to add extra insulation, and aim to keep your bedroom temperature between 19–21°C for optimal comfort if you find the regular temperatures to be a little too cold.
If you struggle with cold feet, a warm wheat bag can help improve circulation and prevent sleep disruption. And while it might be tempting to turn up the heater, overheating can dry out the air and negatively affect sleep quality, so it’s best to keep warmth balanced and breathable.
Key takeaways
- Most adults sleep best between 16°C and 19°C.
- Cooler rooms support your body’s natural sleep-wake cycle.
- Babies and older adults may need slightly different temperatures.
- Maintaining the right bedroom temperature promotes deeper, uninterrupted sleep.
- Seasonal adjustments are important — your summer setup might not work in winter.
- The right mattress can support thermal comfort and improve overall sleep quality.
Getting your bedroom temperature right is one of the simplest, most effective ways to improve your sleep. Whether you’re navigating summer heat or winter chills, Sealy supports you with thoughtfully designed mattresses and materials that adapt to your body and your climate.
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FAQs on sleep temperature
Is 22°C too warm for sleep?
22°C can be slightly warm — most adults sleep best at 18–20°C.
Should I sleep warmer or cooler?
It is better to sleep cooler. Your body sleeps best when the room is cooler than your core temperature.
What happens if the room is too hot?
If your bedroom is too hot, it may cause sweating, frequent waking, and trouble reaching deep sleep.
What temperature should the aircon be for sleeping?
A sleeping temperature of 18–19°C is ideal for most adults.
Can the wrong temperature cause insomnia?
Yes, the wrong temperature can cause insomnia. A sleep environment that’s too hot or too cold may lead to difficulty falling or staying asleep.
Do mattresses really affect sleep temperature?
Yes, your mattress can affect your sleep temperature. Materials like memory foam can trap heat, while breathable options (like those in Sealy’s range) help maintain a consistent, cool environment.
