Is Winter Throwing Off Your Sleep?

Reduced light may disrupt sleep but it’s fixable

A young black woman lies in bed having trouble falling asleep.  San Diego Health Magazine

Reduced light may disrupt sleep but it’s fixable

Winter in San Diego means fewer tourists, peak whale-watching season and festive light displays. On the flip side, it also means shorter, darker days. And if you’re someone who struggles to get a good night’s sleep during winter months, know that you’re not alone.  


Reduced sunlight could be the reason why some people have a hard time sleeping during winter, says Derek Loewy, PhD, a clinical psychologist and sleep medicine specialist at Scripps Clinic. While humans do have an internal clock — known as circadian rhythm — that plays a role in regulating our sleep schedules, it’s not a 24-hour clock. Instead, explains Dr. Loewy, it’s slightly longer, somewhere between 24 hours and 12 minutes to 24 hours and 18 minutes for each person.  


“In other words, left to our own devices, we’re all prone to falling asleep later every night and waking up later every morning,” he says.  


The sun is one of the major contributors to keeping our circadian rhythm in check. When the sun rises later in the winter, it can throw off our sleep schedule.  


“When it’s time to wake up, we want the sun to be there,” Dr. Loewy says. “The sunlight entering our eyes informs the internal clock that it is definitely time to wake up. It’s a signal that turns off our natural melatonin.”  


At the other end of the spectrum, winter’s earlier sunsets can be just as problematic.  


“If the sun’s going down earlier, there is more of a predisposition for sleepiness and going to bed earlier,” Dr. Loewy says. But falling asleep earlier doesn’t mean you’ll sleep longer — you may just wake up in the middle of the night. Alternatively, Dr. Loewy notes, going to bed earlier doesn’t mean you’ll actually fall asleep.  

Could it be seasonal depression? 

On top of all this sun-driven sleep confusion, winter ushers in a rise in seasonal depression, which can come with many side effects, including disruptions to your sleep schedule.  


The most severe form of winter-related depression is known as Seasonal Affective Disorder (SAD), which is recognized as a clinical condition. 

Overcoming winter sleep woes 

Fortunately, there are ways we can trick our brains into not giving into the effects of winter’s reduced light.  


For starters, don’t let yourself lay down on the couch in the dark in the evenings, Dr. Loewy says. If you’re indoors, keep the lights on and try to do something stimulating.  


In the mornings, resist the urge to sleep in. Stick to your regular sleep schedule and access as much light as you can, even if it’s artificial.  


For those struggling with seasonal depression, Dr. Loewy suggests light boxes that mimic natural sunlight and can be particularly helpful in the evenings and mornings.  


Dr. Loewy recommends practicing good sleep hygiene to better set yourself up for a truly restful night of sleep.  This includes things like: 


  • Avoiding caffeine in the evenings 
  • Setting a nighttime routine 
  • Getting your electronics out of the bedroom  


Make sure to talk to your doctor if you’re regularly having trouble sleeping. 

SD Health Magazine Winter 2024 Cover

This content appeared in San Diego Health, a publication in partnership between Scripps and San Diego Magazine that celebrates the healthy spirit of San Diego.