Pumpkin-flavored everything everything is back, the air finally feels crisp, and yet somehow you're dragging yourself out of bed like it's February. If you've been wondering why you're so tired in the fall, you're not imagining it!
As the days get shorter, your body is responding to a real change in its environment. Your internal clock runs on light, and in autumn the light is changing fast. Add in the end of daylight saving time and a busier back-to-routine calendar, and it's no wonder your energy feels off.
The good news: your body clock is flexible. With a few seasonal tweaks, you can help it catch up and feel more like yourself again.
Your circadian rhythm is your body's roughly 24-hour internal clock. It tells you when to feel alert, when to feel sleepy, when to release hormones like cortisol and melatonin, and even when your digestion is most efficient. The strongest signal that keeps this clock on time is light, especially morning light.
After the autumn equinox, many of us lose a couple of minutes of daylight every day. Sunrise creeps later, so you're more likely to wake up in the dark, and your brain gets a weaker "it's morning!" signal. Meanwhile, we spend our evenings under bright indoor lights and screens, which sends the opposite message right when your body should be winding down.
The result is a clock that drifts later. Melatonin, the hormone that helps you feel sleepy, starts releasing later at night and lingers into the morning. That's a big part of why your alarm feels so brutal right now.
How much does light matter? In one well-known study, researchers sent adults camping for a week with only natural light (no flashlights or phones). Their internal clocks shifted about two hours earlier and lined up with sunrise and sunset, and the "night owls" in the group shifted the most (Wright et al., 2013).
You don't have to go camping to get that benefit, though. Small, consistent changes add up.
If you're looking for the basics, like a consistent bedtime, cutting back on afternoon caffeine, or using a light therapy box, we cover those in How to Optimize Your Circadian Rhythm This Winter. The tips below are all about the seasonal shift happening right now.
Even on a cloudy fall morning, outdoor light is much brighter than typical indoor lighting. Getting outside soon after you wake up is one of the clearest signals you can give your body clock that the day has started.
Try it:
Morning light helps set your clock, and evening light pushes it later. In one study, reading on a light-emitting tablet before bed delayed melatonin, made it harder to fall asleep, and left people less alert the next morning compared to reading a printed book (Chang et al., 2015).
Fall is the perfect season to make evenings cozier on purpose. Switch to lamps instead of overhead lights, light a candle, turn on night mode on your devices, and give yourself a screen-free buffer before bed. Your body will read those cues as "time to wind down."
Light isn't the only thing your body uses to tell time. Food timing sends signals too, especially to the clocks in your liver and gut. Researchers found that shifting meals five hours later also shifted the timing of blood sugar rhythms, even when sleep and light stayed the same (Wehrens et al., 2017).
You don't need a strict eating window to use this. Just aim to eat your first meal around the same time each day, ideally within a couple of hours of waking. A warm, protein-rich breakfast is a great fit for chilly mornings.
Daylight saving time ended on November 1, bringing earlier sunsets and brighter mornings. While gaining an hour might sound like a bonus, the shift can temporarily disrupt your sleep-wake schedule. Your body may need several days to adjust to the new timing of light and darkness. The American Academy of Sleep Medicine has even called for ending seasonal time changes because of their effects on sleep and health (Rishi et al., 2020).
A few ways to help your body settle into the new schedule:
Get outside in the morning to reinforce your body's natural wake-up signals.
Keep your bedtime and wake-up time consistent, including on weekends.
Try to eat meals around your usual times to maintain consistent daily rhythms.
Avoid making big shifts to your sleep schedule, even if you're feeling tired.
Keeping your weekend wake-up time close to your weekday one can also help prevent what's known as "social jet lag," which is associated with poorer sleep and metabolic health (Roenneberg et al., 2012).
When energy dips, it's tempting to reach for quick sugar and extra coffee, which can lead to more crashes later in the day. Fall produce makes it easier to build meals that keep your energy steady: fiber-rich squash, sweet potatoes, apples, pears, beets, and hearty greens.
Looking for inspiration? Read 17 Ways to Make the Most of Seasonal Fall Produce, or try a few of our Functional Fall Recipes. And for cozy afternoons, swap the sugary latte for one of these lower-sugar fall drinks.
Feeling a little sluggish as the seasons change is common. But if your low energy comes with a persistently low mood, losing interest in things you usually enjoy, oversleeping, or changes in appetite, it may be worth talking with your healthcare provider. Seasonal affective disorder (SAD) is a type of depression that follows a seasonal pattern, usually starting in late fall and lifting in spring (National Institute of Mental Health, n.d.).
Your provider can also check for other common causes of fatigue, like low iron, thyroid changes, or low vitamin D, which tends to dip as sun exposure drops.
And remember that energy isn't only about sleep and food. Stress, relationships, and how you feel about your work all play a role. If you've been running on empty for a while, these natural ways to boost your energy and our guide to nervous system self-care are great next reads.
If you're tired in the fall, your body is doing exactly what it's designed to do: respond to less light. Morning light outdoors, dimmer evenings, consistent meal times, a steady sleep schedule, and seasonal, energizing foods can help your internal clock find its rhythm again.
Want to understand how your hormones, sleep, and energy all work together? Our Hormone Health Course dives into the systems that shape how you feel every day, so you can support your body through every season.
Help Yourself & Others Feel More Energized Through Every Season
Want to take your passion for wellness even further? The Health Coach Training Program™ explores how nutrition, lifestyle, and daily habits shape well-being—and helps you develop the coaching skills to support others as they make changes of their own. Start with your own health, and discover where that knowledge could take you.
Chang, A.-M., Aeschbach, D., Duffy, J. F., & Czeisler, C. A. (2015). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proceedings of the National Academy of Sciences, 112(4), 1232–1237. https://doi.org/10.1073/pnas.1418490112
National Institute of Mental Health. (n.d.). Seasonal affective disorder. U.S. Department of Health and Human Services. Retrieved September 30, 2026, from https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder
Rishi, M. A., Ahmed, O., Barrantes Perez, J. H., Berneking, M., Dombrowsky, J., Flynn-Evans, E. E., Santiago, V., Sullivan, S. S., Upender, R., Yuen, K., Abbasi-Feinberg, F., Aurora, R. N., Carden, K. A., Kirsch, D. B., Kristo, D. A., Malhotra, R. K., Martin, J. L., Olson, E. J., Ramar, K., . . . Gurubhagavatula, I. (2020). Daylight saving time: An American Academy of Sleep Medicine position statement. Journal of Clinical Sleep Medicine, 16(10), 1781–1784. https://doi.org/10.5664/jcsm.8780
Roenneberg, T., Allebrandt, K. V., Merrow, M., & Vetter, C. (2012). Social jetlag and obesity. Current Biology, 22(10), 939–943. https://doi.org/10.1016/j.cub.2012.03.038
Wehrens, S. M. T., Christou, S., Isherwood, C., Middleton, B., Gibbs, M. A., Archer, S. N., Skene, D. J., & Johnston, J. D. (2017). Meal timing regulates the human circadian system. Current Biology, 27(12), 1768–1775. https://doi.org/10.1016/j.cub.2017.04.059
Wright, K. P., Jr., McHill, A. W., Birks, B. R., Griffin, B. R., Rusterholz, T., & Chinoy, E. D. (2013). Entrainment of the human circadian clock to the natural light-dark cycle. Current Biology, 23(16), 1554–1558. https://doi.org/10.1016/j.cub.2013.06.039