by Ever wondered why you struggle to sleep on a sweltering night in summer but sleep like a log in winters? You may think it’s due to your lifestyle, diet, or health changes, but there’s actually science behind it: weather changes.
Research shows that different weather conditions can affect your sleep duration and patterns and may even lead to a number of sleep problems. But why does this happen? The answer lies in changes in temperature, light, and humidity that disrupt your body’s internal clock called circadian rhythms.
This blog will explore the complex relationship between weather changes and sleep, shedding light on how temperature, humidity, and seasonal changes can influence sleep patterns and potentially lead to sleep problems.
The Relationship Between Sleep and Weather
You probably didn’t know this, but your body has a built-in sleep-wake cycle known as the circadian rhythm. This cycle is regulated by an internal biological clock located in the brain’s hypothalamus. This internal clock responds to external cues, primarily light and temperature, to maintain a 24-hour cycle, helping us follow a set sleep pattern every day.
When weather changes, it can influence these external cues. For example, as summer approaches, the days get longer with more daylight, while in winter, days get shorter, with nighttime extending to 14 hours or more. These changes in temperature and light can affect our circadian rhythms and, consequently, our sleep.
Role of Temperature and Light on Our Sleep
Studies have shown that temperature and light exposure signal our bodies when it is time to sleep and wake up. For instance, cooler temperatures and darkness tell the body to produce melatonin, a hormone that promotes sleep. That’s why you sleep early in bundled winters.
Conversely, warmer temperatures and light exposure signal the body to reduce melatonin production, making us feel more awake, which is what you experience during May to October.
The body’s core temperature naturally decreases during sleep, reaching its lowest point in the early morning hours. This drop in temperature helps promote deep sleep and REM sleep, which is where most dreaming occurs and is crucial for cognitive functions such as memory consolidation and learning.
That said, the temperature of your bedroom plays an important role in your sleep pattern. Sleep experts at Sleepwell say the ideal bedroom temperature for sleep is generally between 15-25°C (60-70°F). Temperatures outside this range can disrupt your sleep by making it difficult to fall asleep or stay asleep.
How Hot Temperatures Create Sleep Problems
Just as you remember ‘the Summer of 69,’ most people will, in all likelihood, remember the summer of 2024. Why? Because it has witnessed record-breaking temperature points, reaching up to 52°C (125°F) in New Delhi. These extreme temperatures are not suitable for the human body, causing heatstroke, sunburn, and many other health problems. These problems take a drastic toll on sleep patterns and create many complications.
Hot temperatures can prevent the body from cooling down, leading to difficulty falling asleep and frequent awakenings during the night. Frequent awakenings or difficulty falling asleep can result in reduced REM sleep, making you feel groggy and impacting your cognitive function the next day.
While cooler temperatures (15-25°C or 60-70°F) can promote sleep onset, excessively cold environments can also disrupt sleep. You may shiver or feel too cold in higher altitude regions where temperatures fall below zero degrees. This can cause frequent awakenings and discomfort, preventing restorative sleep.
The Role of Humidity in Sleep Quality
The level of humidity in the air also has a huge role in our sleep patterns. High humidity can snowball the effects of hot temperatures by making it harder for sweat to evaporate, preventing the body from cooling down, and causing restless sleep and frequent awakenings.
Low humidity, on the other hand, causes the air to dry, leading to dehydration of the skin and mucous membranes. This leads to a dry throat, nasal congestion, and an increased risk of respiratory infections, all of which can make falling asleep harder.
Seasonal Changes and Their Impact on Sleep
Since different temperatures and light levels affect our sleep schedule differently, it’s no surprise that different seasons do the same to our sleep patterns. Let’s look at each season:
Spring
Spring brings many changes. As flowers bloom and pollen from the trees showers down, allergies at night roar. Pollen allergies are known to reduce sleep quality by worsening hay fever symptoms, causing coughing and sneezing that disrupt relaxation during wind-down time.
Also, our bodies receive the signal to relax through melatonin, which is released in response to the transition from light to dark. Increased light exposure later in the evening in spring can throw off our natural circadian rhythm, delaying melatonin production. This shift can interfere with our body’s schedule and understanding of when it’s time to rest.
Fall
In the fall, the end of daylight saving time means clocks move back an hour. While gaining an extra hour of sleep may be easier for some, it can still disrupt our circadian rhythm, making us feel sleepy earlier in the evening due to earlier sunset times. Sleepwell experts suggest gradually adjusting your sleep schedule in the weeks leading up to the time change, similar to preparations for the spring transition.
However, shorter days and earlier sunsets can work against us, as decreased light exposure can lead to daytime sleepiness and sluggishness. Experts recommend avoiding oversleeping, as it can cause sleep inertia and lethargy the next day. Fall allergies can also disrupt sleep and cause oversleeping, but taking preventive measures may help.
Despite the challenges of the time change, some people may experience improved sleep in the fall. As temperatures drop to pleasantly cool levels, the weather creates an ideal environment for quality sleep. Keeping your room cool at night—either by opening a window or setting the AC on low—can also enhance sleep quality.
Winter
Out of the four seasons, winter may present the most significant sleep challenges. In winter, days are often shorter than 12 hours, resulting in more darkness than sunlight, especially after the winter solstice in January and February.
Experts at Sleepwell say winter months are perhaps the most disruptive to our sleep and general well-being because the days are at their shortest. They further said that not only does this negatively impact sleep, but it also carries a serious risk of causing seasonal depression.
This mood disorder affects up to 6% of the population in winter, with many experiencing hypersomnia, or excessive sleeping. One study found that out of 293 patients with seasonal depression, 80% reported hypersomnia, while only 10% reported insomnia.
Summer
Excess light exposure in the summer, particularly in northern states with sunsets as late as 8 p.m., extends the time we stay awake. Both light and temperature play significant roles in signaling to our bodies that it’s time to sleep, coinciding with melatonin release. An increase in temperature can make it harder to fall and stay asleep.
Researchers note that humid heat, in particular, can add to the body’s thermal load, causing more frequent awakenings throughout the night. Environmental heat can also increase heart rate, leading to poor sleep. These disruptions can result in decreased slow-wave sleep, a crucial stage of sleep for processing emotions and memories.
Weather-Related Sleep Disorders You Should Know About
Weather changes can also exacerbate certain sleep disorders, making it essential to understand their impacts and how to manage them. Here are some sleep problems that weather changes can worsen:
Insomnia
Insomnia, characterized by difficulty falling or staying asleep, can be worsened by extreme temperatures and humidity levels. If you have insomnia, try maintaining a stable and comfortable sleep environment.
Sleep Apnea
Sleep apnea, a condition where breathing repeatedly stops and starts during sleep, can be affected by weather changes, particularly humidity levels. Low humidity can dry out airways, while high humidity can increase the risk of respiratory infections, both of which can worsen sleep apnea symptoms.
Restless Legs Syndrome (RLS)
RLS, characterized by an uncontrollable urge to move the legs, can be triggered by temperature changes. Cold weather can exacerbate symptoms, making it harder to sleep.
In a Nutshell
Most people have no idea whether weather impacts their sleep or not. However, knowing the link between the two can help you take necessary steps to ensure you sleep comfortably and without interruption every season. Besides taking practical steps to combat the effects of different seasons, ensuring your sleep environment, primarily the mattress, supports with best sleeping mattress is crucial.
