How Summer Affects Sleep

We long for many parts of summer all year—family vacations, swimming and long, sunny days. But as much as we love the season, the heat can become a real problem when it's time to wind down for the night.

One reason it's harder to sleep in the summer is that evening temperatures don't drop as much after extremely hot days. Scientists from the National Oceanic and Atmospheric Administration reported that July 2023 was the hottest month Earth has experienced in the organization's 174-year history. Those high temperatures can increase wakefulness while decreasing the chances of reaching REM sleep (when we dream).

Another cause is our increased sunlight exposure. Sure, we love to spend more time outdoors in the summer, but those earlier sunrises and later sunsets hinder melatonin production. The lack of that sleep hormone keeps us from deep, restorative sleep.

And that's dangerous. Inadequate sleep can lead to increased heart disease, obesity and diabetes risk. It also can weaken the immune system and cause decreased cognitive function.

So, what can we do to help you say, "But ah! Oh, the summer nights," rather than, "Ugh! Those summer nights"? To sleep comfortably during hot nights, it's important to:

Avoid heat and light. Close the blinds to reduce heat in your home during the day and before you settle in for the night. In addition, exposure to light in the evening, from the sun or even electronic devices, disrupts our natural sleep-wake cycle and makes it harder to fall asleep. Some experts say you should start dimming the lights and avoiding screens as much as two hours before bed.

Keep a sleep schedule. Go to bed and wake up at the same time every day, even on weekends and holidays. This helps regulate your body's internal clock and promotes better sleep. The Sleep Foundation reports people with consistent sleep schedules are more likely to report feeling well-rested than those who change up their bedtimes.

Limit caffeine and alcohol consumption. Caffeine can make it hard to fall asleep, while alcohol can disrupt your sleep cycle and cause you to wake up frequently throughout the night. One study found that high amounts of alcohol can decrease sleep quality by up to 39%.

Stay cool. Use a fan and/or air conditioning (the magic number is 65 degrees, by the way). Some people also invest in a cooling mattress, take a cool shower before bed or put their pillowcases in the freezer. You also could consider sleeping in light, breathable pajamas or—like 28.5% of people—your birthday suit.

We don't need to know the details. We just want you to sleep well.

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