


“This is one reason why you might wake up earlier and sleep a little less in summer.” Stress “Due to the longer daylight hours in summer, the time of melatonin secretion is shorter than in winter,” Lederle says. As the sun comes up, melatonin secretion stops so the body can prepare for the day. When it gets dark, our body clock signals that it’s time to sleep with the release of the hormone melatonin. “The longer we ‘see’ light, the longer the body clock will tell the body it’s daytime and it needs to stay awake.” Delayed melatonin release

“Your body clock, which is located in your brain, uses light and darkness as signals for day and night,” she says. Lederle is a sleep scientist, chronobiologist, and head of sleep at Somnia. “The longer daylight hours and the higher, sometimes humid, temperatures make it difficult to sleep well,” says Kat Lederle, PhD, MSc. The same study identifies light as the single most important external factor affecting circadian rhythm, the body’s internal clock that controls our sleep-wake cycle. This is a sleep phase that contributes to feelings of restfulness. Increased daylight hoursĪ 2019 study notes that exposure to light later in the day contributes to more episodes of waking during the night and less slow-wave or delta sleep. Here are some reasons you may not be sleeping as well during summer. Researchers found that waking times were earlier in the summer, while sleep issues such as insomnia and fatigue were less common in winter (although people can still have sleep issues in winter). According to a 2011 study, seasonal variations can affect how well we sleep.
