Sleeping through a Gulf summer: how to sleep in hot weather

Why is it harder to sleep in hot weather?

Falling asleep is partly a cooling process. In the hour or so before sleep, your core temperature drops a little, and more blood moves towards the skin to let heat out. That small drop is one of the body’s signals that it is time to sleep.

A warm room slows it down. If the air around you is close to your skin temperature, there is less room for heat to leave. You lie awake longer, and the sleep you get is lighter.

This is why the same person can sleep well in February and badly in August, with nothing else in their life changed.

How hot are Gulf summer nights?

The World Meteorological Organization publishes 30-year climate averages for weather stations. For 1991 to 2020, the average night-time low at Dubai International Airport is 31.2°C in July and 31.5°C in August. In Riyadh, the average low is 29.4°C in July and 29.5°C in August.

Those are averages, not the hot nights. On the coast, humidity adds to the load, because sweat evaporates less easily in damp air.

So in a Gulf summer, opening a window at night does not cool a bedroom the way it might in a cooler country. The room you sleep in, and how you set it up, carries almost all of the work.

What does a hot night do to your sleep?

The research is consistent.

A 2012 review by Kazue Okamoto-Mizuno and Koh Mizuno in the Journal of Physiological Anthropology found that heat during sleep increases time spent awake and reduces slow-wave sleep, the deepest stage, and REM sleep, the stage most linked with dreaming. Humid heat raises the load further.

A 2022 study in One Earth, led by Kelton Minor, linked more than 7 million nights of sleep from wristband data in 68 countries with local weather. On nights above 30°C, sleep fell by an average of just over 14 minutes. Most of the loss came from falling asleep later, with some from waking earlier. Older adults and women were affected more.

The heart feels it too. A 2025 study of 47 adults aged 65 and over in Australia, published in BMC Medicine, found that warmer bedrooms were linked to higher heart rates and lower heart rate variability during sleep. Compared with nights below 24°C, bedrooms at 28 to 32°C came with about three times the odds of a meaningful drop in heart rate variability.

Heart rate variability, or HRV, is the small variation in time between heartbeats. It tends to be higher when the body is recovering and lower when it is under load. We explain more in our guide to what 46°C does to your body.

Why do humid nights on the coast feel worse?

Sweat cools you only when it evaporates. A 2023 review in Environmental Health Perspectives, led by Jane Baldwin, explains that as humidity rises, less of the sweat you make evaporates, and the rest drips off or stays on the skin.

At night, that means a humid bedroom holds on to your heat. The 2012 review above found that humid heat raises the thermal load during sleep and changes sleep stages more than dry heat does. On the coast, the WMO averages show the air holding the most water vapour in July and August, the same months as the warmest nights.

Moving air across the bed, from a fan or the air conditioning, can help what sweat there is evaporate.

Who needs a cooler bedroom most?

Everyone sleeps worse in the heat, but some people feel it more. The WHO names people over 65 and people with heart disease, lung conditions, diabetes or kidney disease among those most affected by heat. The NHS adds babies and children aged 5 and under.

The NHS also suggests checking the temperature of rooms where these family members sleep, not only the rooms where the rest of the house spends the evening. A grandparent’s room at the sunny end of the house, or a child’s room with a weaker air conditioning unit, can run warmer than the living room.

How much sleep do adults need?

The American Academy of Sleep Medicine and the Sleep Research Society recommend that adults sleep 7 or more hours a night on a regular basis.

A summer of 14-minute losses adds up, and so do late summer evenings. The two together can take a real bite out of the night.

How to sleep in hot weather: what helps

None of these steps is new. They work because each one either cools the body or protects the time you have for sleep.

1. Cool the bedroom before bed. The CDC recommends a bedroom that is quiet, relaxing and at a cool temperature. For older family members, the 2025 BMC Medicine study suggests keeping night-time bedrooms at or below 24°C.
2. Keep the sun off the bedroom windows. The NHS suggests closing curtains and blinds while the sun is on them. A room that has not soaked up the afternoon is easier to cool.
3. Keep the room dark and quiet. The NHS lists a dark, quiet bedroom among its first steps for better sleep.
4. Take a warm shower one to two hours before bed. A 2019 review in Sleep Medicine Reviews found that warm water at about 40 to 42.5°C, one to two hours before bedtime, was linked to falling asleep about 10 minutes faster. The body sheds heat afterwards, and that helps the natural drop in core temperature.
5. Put screens away half an hour before bed. The CDC recommends turning off electronic devices at least 30 minutes before bedtime.
6. Move the big meal and the coffee earlier. The CDC advises avoiding large meals and alcohol before bedtime, and caffeine in the afternoon or evening. The NHS suggests no tea or coffee in the 6 hours before bed.
7. Keep your wake-up time steady. The CDC recommends going to bed and getting up at the same time every day. The NHS suggests getting up at the same time every day, whatever the night was like.

Exercise helps sleep, and the NHS lists regular daytime exercise among its steps. In a Gulf summer, that usually means early morning or after sunset. The NHS also suggests finishing exercise at least 4 hours before bed, which is worth keeping in mind for late evening workouts.

What mistakes make hot nights worse?

Some habits feel sensible after a bad night but make the next one harder. The NHS names several:

• Sleeping in after a bad night. It pushes the next night later.
• Napping during the day. The NHS advises against daytime naps for people with insomnia, however tempting the cool of the house in the afternoon.
• A big meal late at night. Summer dinners often start late. A heavy plate close to bedtime works against sleep.
• Screens in bed. Television and phones right before sleep keep the mind switched on.
• Tea and coffee late in the day. The NHS suggests none in the 6 hours before bed.

Seasons that move the whole day around, such as Ramadan, change sleep in their own way. We cover that in how Ramadan changes your sleep.

What can your readings show on hot nights?

If you wear a sleep tracker, a hot week may show up before you name it. Later sleep, a shorter night, a resting heart rate a little higher than usual, or a lower HRV can all come with the heat.

Sisly reads sleep, energy, stress, heart rate variability, activity and skin temperature, and shows each one against your own normal. Seeing a summer night against your own pattern, rather than someone else’s, makes it easier to read a hot week as a hot week. When the weather turns in October, your nights often turn with it.

For more ideas on the first half hour in bed, see our shorter guide on falling asleep faster in a hot city.

When should you see a doctor about sleep?

The NHS suggests seeing a doctor if changing your sleep habits has not helped, if you have had trouble sleeping for months, or if insomnia is affecting your daily life in a way that makes it hard to cope. It calls insomnia that lasts 3 months or longer long-term insomnia.

Heat can explain a few rough weeks. It does not explain everything. If your sleep stays short once the weather cools, or you are very sleepy during the day, talk to your doctor.