Getting a good night’s sleep starts long before bedtime. One of the most powerful yet often overlooked ways to improve sleep quality is exposure to natural light in the morning. Research shows that morning sunlight plays a critical role in regulating the body’s circadian rhythm, also known as the internal body clock. This rhythm influences when we feel awake, when we get sleepy, and how well we rest at night.
The circadian rhythm is primarily controlled by light exposure. When sunlight enters the eyes in the morning, it signals the brain to reduce melatonin production, the hormone responsible for sleep. At the same time, it boosts the release of cortisol, which promotes alertness and energy. A study published in The Journal of Clinical Sleep Medicine found that individuals who were exposed to natural morning light had an easier time falling asleep at night and reported overall better sleep quality.
Morning light also helps regulate serotonin, a neurotransmitter that influences mood and sleep. Sunlight exposure during the day boosts serotonin levels, which not only enhances mood but also plays a role in the nighttime production of melatonin. Research from The National Institute of General Medical Sciences suggests that people who get enough morning light tend to have more consistent sleep patterns, whereas those who lack light exposure may experience sleep disturbances and insomnia.
Timing and duration of light exposure are important factors. According to a study published in Sleep Health, getting at least 30 minutes of sunlight within the first hour of waking can significantly improve sleep quality. This is because early daylight exposure strengthens the circadian rhythm, making it easier to feel awake during the day and naturally tired in the evening. In contrast, insufficient daylight exposure has been linked to delayed sleep onset and irregular sleep cycles.
Artificial lighting does not provide the same benefits as natural sunlight. Indoor lighting, even when bright, lacks the full spectrum of light waves that regulate the body’s internal clock. Research published in The Journal of Pineal Research found that exposure to blue light from electronic screens in the evening suppresses melatonin production, further disrupting sleep. This is why morning sunlight is especially crucial—it sets a strong foundation for the body’s natural sleep-wake cycle and reduces the negative impact of artificial lighting later in the day.
For those who do not have access to ample morning sunlight, light therapy boxes can serve as an alternative. According to the American Academy of Sleep Medicine, light therapy has been shown to help reset the body clock in individuals struggling with insomnia, seasonal affective disorder, and circadian rhythm disruptions caused by shift work. However, natural light remains the most effective and accessible option for most people.
Incorporating morning light into a daily routine is simple and effective. Stepping outside for a morning walk, sitting near a bright window, or having breakfast on a patio can all provide enough exposure to reinforce a healthy sleep cycle. Even on cloudy days, outdoor light is significantly stronger than indoor lighting and still offers sleep-regulating benefits.
The science is clear—morning sunlight is a powerful tool for better sleep. By aligning the body's internal clock with natural light patterns, people can fall asleep more easily, stay asleep longer, and wake up feeling refreshed. Prioritizing exposure to sunlight in the morning can lead to long-term improvements in both sleep and overall well-being.
Disclaimer: This article is for informational purposes only and should not be considered medical advice. If you experience persistent sleep issues, consult a healthcare professional for personalized recommendations.
References
- The Journal of Clinical Sleep Medicine. “The Effects of Morning Light Exposure on Sleep Quality and Circadian Rhythm.”
- The National Institute of General Medical Sciences. “Serotonin and Melatonin: The Role of Light in Sleep Regulation.”
- Sleep Health. “Morning Light Exposure and Its Impact on Sleep Patterns.”
- The Journal of Pineal Research. “The Effect of Artificial Light on Melatonin Suppression and Sleep Disruption.”
- American Academy of Sleep Medicine. “Light Therapy for Sleep and Circadian Rhythm Disorders.”