How Longer Days Affect American’s Sleep
We’re taking a look at how summertime’s longer days and warmer weather affect sleep for Americans nationwide. We’ll be examining whether seasonal differences matter for sleep and what longer summer days mean for our sleep-wake patterns. Plus, get science-backed tips to help keep your sleep in-check throughout the year.
Do Changing Seasons Matter for Sleep?
For millions of Americans, summer is synonymous with vacation plans, social gatherings, sunshine, and warmer days. However, while the extended sunlight may be nice, too much exposure to bright light close to bedtime may impair our production of melatonin, which is an important sleep-wake hormone, and further impact our sleep and circadian rhythms (Bedrosian & Nelson, 2023).
“Melatonin is often referred to as the hormone of darkness because it’s stimulated and produced by the pineal gland in response to darkness,” says SleepScore Labs Applied Sleep Scientist Dr. Elie Gottlieb, Ph.D.
In Seattle, sunlight may shine for up to 16 hours versus 14 hours in Miami during the peak of summer.
How Do Longer Days Shift American’s Sleep-Wake Patterns?
Based on SleepScore Labs’ updated analysis in 2025, sleep schedules continue to shift during summer’s longer days. Across June 2024 data, Americans went to bed and woke up an average of 12 minutes later than in the winter months. For example, in January and February, the average bedtime was around 11:05PM, which moved to 11:17PM by July. Wake-up times increased from 6:55AM in February to 7:07AM in July (SleepScore Labs, 2025).
These shifts weren’t just in bedtime and wake-up times. The longest days of the year also correlated with the shortest sleep durations. In June 2024, Americans slept an average of 5 hours and 58 minutes—14 minutes less than the 6 hours and 12 minutes reported in November.
That’s a full 98 minutes of lost sleep over a single week.
This decline was more pronounced on weekends. Instead of catching up on rest, Americans slept nearly 22 minutes less on summer weekends compared to weekdays—likely due to increased evening social activities and early morning sun exposure (Medina et al., 2024).
In addition to sleep duration, sleep quality took a dip. Sleep efficiency dropped from nearly 80% in November to 77% in July 2024, according to SleepScore app users. That falls short of the 85% efficiency benchmark set by the National Sleep Foundation for good-quality sleep (National Sleep Foundation, 2024).
The average SleepScore—which evaluates six sleep parameters—also dipped during summer, falling from 81 in November to just under 79 in July (SleepScore Labs, 2025).
Who Is Most Affected by Longer Summer Days?
SleepScore’s 2024 data also revealed that older adults over 60 saw the most dramatic summer sleep reductions—losing nearly 40 minutes of sleep compared to younger adults under 30.
“Older adults tend to have more fragmented sleep and a weakened circadian rhythm, so seasonal changes have a stronger effect on their ability to maintain sleep,” says Dr. Gottlieb (Tsuchiyama et al., 2024).
The takeaway? Americans across age groups are struggling to maintain healthy sleep during summer’s extended daylight hours.
How Are Americans Sleeping Throughout the Year?
Seasonal shifts in sleep don’t stop at summer.
During the holiday season, American sleep schedules shift again—this time for the better. In December 2024, average bedtimes extended from 11:07PM in November to 11:16PM, and wake-up times followed suit, increasing from 7:00AM to 7:11AM.
Unlike the summer shift, this change resulted in more total sleep. Americans logged an average of 6 hours and 16 minutes per night during the holiday season—the highest of any time in the year (SleepScore Labs, 2025).
Even better, sleep quality improved, too. SleepScores peaked in November at 81 and remained steady through December at 80. Sleep efficiency hovered around 80% – making the holiday season truly is the most wonderful time of the year – especially for our sleep.
Ideas To Keep Your Sleep In-Check No Matter the Time of Year
Here are four science-backed tips to help you sleep better regardless what time of year it is.
Stay Out – Use your bedroom strictly for sleep (and intimacy). Avoid working, eating, or watching TV in bed. Doing so helps your brain associate the bed with rest—not wakefulness (American Academy of Sleep Medicine, 2023).
Limit Screen Time – Sleep and light at night do not mix well. Electronic devices emit blue light, which delays melatonin production. Limit screen use in the hour before bed, or use blue light filters or glasses. Try low-light activities like reading or a warm bath to wind down instead (Green et al., 2023).
Cut the Stimulants – For many people, a major step in sleep improvement is identifying sources of caffeine and then reducing caffeine consumption, particularly later in the day. Caffeine can stay in your system for 6+ hours. Aim to stop caffeine intake after 2:00PM. Switch to herbal teas or other non-caffeinated beverages in the afternoon and evening (Smith & Wu, 2024).
Watch What You Eat – Be mindful that your diet can affect sleep. Large or spicy meals close to bedtime can disrupt sleep. Finish eating at least 2–3 hours before going to bed and avoid late-night snacks to allow digestion to complete (Tuhin et al., 2025).
How SleepScore Can Help
Download the free SleepScore App for insights and articles on how well you sleep, the quality and quantity of your sleep cycles, and sleep improvement progress with science-backed tips and insights. Download it for free from App Store and Google Play Store!
Sleep well!
Sources
- Bedrosian, T.A., & Nelson, R.J. (2023). “Seasonal and Circadian Regulation of Sleep.” Current Sleep Medicine Reports. https://doi.org/10.1007/s40675-023-00221-9
- Medina, M.C., et al. (2024). “Environmental Light and Sleep Duration: A Seasonal Perspective.” Sleep Health. https://doi.org/10.1016/j.sleh.2023.11.002
- National Sleep Foundation. (2024). “Understanding Sleep Efficiency.” https://www.thensf.org/sleep-efficiency/
- Tsuchiyama, K., et al. (2024). “Aging and the Sensitivity to Circadian Disruption: Implications for
- Sleep Health.” Chronobiology International. https://doi.org/10.1080/07420528.2024.1009873
- SleepScore Labs. (2025). Internal User Sleep Metrics Report: 2024-2025 Analysis.
- American Academy of Sleep Medicine. (2023). “Sleep Hygiene Recommendations.” https://aasm.org/resources/factsheets/sleep-hygiene/
- Green, K., et al. (2023). “Effects of Blue Light on Sleep and Circadian Rhythms.” Journal of Sleep Research. https://doi.org/10.1111/jsr.13900
- Smith, L., & Wu, P. (2024). “Caffeine Consumption and Sleep Health in Adults.” Sleep Medicine Reviews. https://doi.org/10.1016/j.smrv.2023.101821
- Tuhin, M., et al. (2025). “Study Finds That Sleep Regularity Can Shield Teens from Negative Mood and Anxiety.” Journal of Adolescent Health. https://www.jahonline.org/article/S1054-139X(25)00098-0/fulltext