Why is morning sunlight important?

Morning sunlight helps set the body’s internal clock, supporting daytime alertness and mood while helping time sleepiness and promote restful sleep. It also supports healthy metabolism. 1

• When to get it: Go outside within the first hour after waking. Outdoor light is still useful on cloudy or overcast days; you may need to stay out longer. 2 3
• Sets the internal clock: Morning light signals the central circadian clock, prompting a wake-up response and starting a timer that helps prepare you to fall asleep later. 4
• Supports wakefulness and mood: Morning light helps time the natural cortisol rise that promotes alertness, and is linked with improved mood, focus, and energy. 5 6
• Helps sleep later: Morning light suppresses melatonin that may remain after waking and helps establish the daily pattern of alerting signals in the morning and melatonin at night, supporting easier, more restful sleep. 7 8
• Consistency: Aim to get morning light at least 80% of the time. 9