The Real Reason Your Teen Can’t Wake Up on Fall Mornings

Fall is here and you may have noticed your teen pushing their bedtime later or struggling to wake in the morning. It may be frustrating but it’s not unusual during this time of year.

Experts say there are biological and seasonal reasons behind the fall-time sleep disruption, and understanding them can help teens get better rest. Let’s break it down.

The Science Behind Teen Sleep

As puberty hits, sleep patterns change.

“The hormonal shifts during puberty lead to a natural delay in adolescents’ circadian rhythm,” says Michelle Jean Brock Caraballo, MD, pediatric pulmonologist and sleep medicine physician at Children’s Health and associate professor at UT Southwestern Medical Center. “Their bodies prefer to go to sleep later and wake up later.”

So, if you’re having a hard time waking your teen for school, this is likely not “due to laziness, school avoidance, or anything that is the teenager’s fault; it is a biological process,” reassures Dr. Caraballo. 

Many teens crave a later bedtime, around 10 or 11 p.m., and prefer to sleep in until 8 a.m. or later. This works well during the summer months or over break, but school schedules rarely align with that desire. Although the American Academy of Pediatrics (AAP) recommends an 8:30 a.m. or later start time for adolescents, many schools start around 8 a.m.

This results in teens often running up a sleep debt, leaving them tired and cranky—or “tranky,” as Roger Washington, MD, the medical director of the Sleep To Live Well Foundation, coins it.

Daylight Saving Time and Seasonal Shifts Also Affect Teen Sleep

When Daylight Saving Time ends on November, 2, 2025, much of the United States “falls back” an hour. This may seem like an opportunity for teens to gain extra sleep.

But this abrupt change can actually disrupt their already sensitive sleep patterns, says Rupali Drewek, MD, co-medical director of the Sleep Medicine Program at Phoenix Children’s.

Dr. Caraballo also points out, “The ‘fall backward’ means it gets darker earlier, which results in earlier melatonin release and promotes earlier sleep onset.” Likewise, earlier morning light should help wake the body up, but only if teens are exposed to it. 

This is why Dr. Washington encourages teens to get even 10 minutes of outdoor light first thing after waking up. “Morning light, even on overcast days, helps reset the internal clock and steady mood through shorter fall days,” he says.

Keep in mind, artificial light is a cause of concern. Light is the number one thing that tells our body when to be awake or asleep, Dr. Caraballo says. When we have bright lights or use electronics late in the evening, it makes our brain think it’s still daytime and delays melatonin release, the hormone signaling to the body that it’s time to prepare for sleep.

Why Sleep Matters So Much for Teens 

Chronic sleep deprivation can impact anyone, including teens, in various ways. 

“When teens don’t get enough sleep, their bodies produce fewer infection-fighting cells and antibodies, making them vulnerable to viruses,” says Dr. Drewek, especially during cold and flu season.

Too little sleep has other side effects. According to a 2023 review published by Cambridge University Press, sleep deprivation puts teens at higher risk for obesity and impaired cognitive performance, including alertness, memory, mood, emotion, and behavioral regulation.

Chronic sleep deprivation can also affect cardiovascular health, blood pressure, and inflammation, cautions Pranav Patel, MD, a board-certified clinical cardiologist at Inspira Health.

Tips for Better Teen Sleep

The experts we spoke with share tips to help your teen get the rest they need this season:

• Keep a consistent sleep routine, even on weekends, and encourage them to aim for at least eight to 10 hours.
• Limit screens at least 30-60 minutes before bedtime. 
• Create a wind-down routine, such as reading, journaling, or listening to calming music.
• Leading up to bedtime, turn off bright overhead lights and start using dimmer lamps to promote melatonin release. 
• Keep the bedroom cool, dark, and quiet. 
• Train teens to listen to their body’s cues and encourage an earlier bedtime as a health standard, not punishment. 
• As the adult, model a consistent bedtime.

Dr. Washington reminds parents, “Sleep is the hidden foundation of every need your teen has—from learning and growth to emotional stability. Treat it as non-negotiable, like meals or safety.”

When To Seek Professional Help for a Teen’s Sleep Struggles

Occasional late nights are normal, but persistent sleep disruptions should not be ignored, especially if you notice your teen struggling with mood changes, fatigue, or poor concentration, Dr. Patel says. This can signal mental health challenges or other conditions.

Another cause for concern is sleep apnea, a common but potentially serious sleep disorder. Dr. Patel says if you notice these signs: inconsistent sleep patterns, chronic tiredness despite healthy sleep routines, as well as choking, loud snoring, or gasping during sleep, it’s time to consult with your health care provider or consider a sleep study.