Poor Sleep in Summer: Why and What Really Helps

Does this sound familiar? It's 11 PM, still warm outside, the window is open, and mosquitoes are buzzing. Falling asleep is out of the question. In summer, many people sleep demonstrably worse, and this has specific biological reasons that one should understand before looking for solutions.

In this article, we'll look at why summer heat affects sleep so much, what this has to do with hormones and light, and which methods and supplements truly help instead of just making promises.

Why do we sleep worse in summer?

Poor sleep in summer has three main causes that act simultaneously: excessively high ambient temperature, too much light in the evening and, especially for women over 40, hormonal shifts that further destabilize sleep.

In summer, most people sleep on average 20–30 minutes less per night than in winter anyway. Over weeks, this accumulates into a significant sleep deficit that affects concentration, mood, immune system, and metabolism.

The role of body temperature in falling asleep

Sleep begins with a drop in core body temperature of about 1°C. The temperature drop signals to the brain that it's time to sleep and triggers melatonin secretion.

At high outdoor temperatures, the body cannot cool down efficiently. You lie in bed, you're tired, but you can't fall asleep. Or you fall asleep, but wake up after a few hours because your body is overheating.

Light and melatonin: The underestimated problem

In summer, it gets light early and dark late. This sounds pleasant but is problematic for sleep. Melatonin, our sleep hormone, is only produced in darkness. Longer periods of light in the evening delay melatonin secretion by 1–2 hours.

Added to this is the blue light problem: smartphones, tablets, and laptops emit blue light that stimulates the same receptors in the brain as daylight. Those who look at screens in the evening significantly intensify this effect.

The result: The body is not yet biologically ready for sleep, even though the clock says it's time, and the subjective feeling of "I just can't fall asleep even though I'm tired" arises.

Menopause and sleep: A double problem

For women in peri- and postmenopause, summer sleep is particularly challenging because two problems overlap: external heat and internal hot flashes.

Nocturnal hot flashes, also known as night sweats, usually interrupt sleep in the second half of the night, precisely during the important REM sleep phase. This leads to a sleep architecture that does not feel restorative, even with sufficient hours of bedtime.

If you want to learn more about hot flashes and natural methods to combat them, you will find a comprehensive overview in our article on Hot flashes in menopause.

What really helps: 7 methods for better sleep in summer

1. Keep the bedroom cool during the day

Keep blinds or blackout curtains closed during the day and only ventilate in the evening when the outside temperature drops below the indoor temperature. This is more effective than ventilating all day.

2. Cool your body before bed

A lukewarm (not cold) shower or bath before bed supports the natural drop in body temperature. Cold water has the opposite effect, it activates circulation instead of calming it.

3. Reduce light in the evening

Blackout curtains, blue light filters in the evening (on devices or as glasses), and dim, warm light in the hour before sleep. This signals to the body that it's getting dark and it's time for melatonin.

4. Maintain consistent sleep times even in summer

The circadian rhythm doesn't like exceptions. If you sleep 2 hours later on weekends, you shift your internal clock, and the so-called "social jetlag" makes it harder to fall asleep during the week.

5. Light evening meals

Heavy, fatty meals in the evening increase body temperature during digestion. Especially relevant in summer is light food, at least 2–3 hours before sleep.

6. Breathable bedding

Linen or cotton instead of synthetic fibers. Linen has the best moisture-wicking properties and stays cool even with body heat, which makes a measurable difference.

7. Establish an evening routine

The nervous system needs a signal that the day is ending. The same routine every evening, whether reading, stretching, or short meditation, trains the brain to fall asleep. This is not a matter of willpower but of conditioning.

Supplements for better sleep: What research shows

5-HTP: the serotonin precursor

5-HTP (5-hydroxytryptophan) is a naturally occurring amino acid and a precursor to serotonin, from which the body can then produce melatonin. Therefore, 5-HTP is often used to support mood and sleep. Some studies suggest it could improve sleep quality, but the evidence is still limited.¹

Important: 5-HTP should not be taken with antidepressants (especially SSRIs). If in doubt, always consult a doctor first.

Magnesium, the relaxation mineral

Magnesium plays an important role in regulating the nervous system and sleep-wake cycles. Among other things, it influences GABA- and melatonin-dependent processes that are relevant for relaxation and sleep. Studies show that magnesium supplementation can improve sleep quality, especially in older people with sleep problems. Low magnesium intake is also frequently associated with poor sleep.²

Melatonin

Melatonin is the best-known sleep supplement – but it is often misunderstood. It does not act like a classic sleeping pill, but primarily serves as a biological time signal for the body: "It's night." Especially with shifted sleep rhythms, jet lag, or difficulty falling asleep, a low dose (about 0.5–1 mg) 30–60 minutes before bedtime can be helpful. Higher dosages are often not more effective and can lead to side effects such as morning fatigue or a shift in the sleep rhythm.³

Ashwagandha: Stress and sleep

Ashwagandha is classified as an adaptogen and could help modulate the body's stress responses, a factor often associated with sleep problems. In a randomized, placebo-controlled study, a standardized ashwagandha extract showed improvements in sleep onset latency, sleep quality, and sleep efficiency, as well as a reduction in anxiety symptoms, over 10 weeks. Previous studies indicate potential positive effects, but the evidence base is still limited, and further larger studies are needed.⁴

Advertisement

Support for your sleep!

My personal routine

To be honest, I sleep significantly worse in summer than in winter, even though I know what helps. What makes the biggest difference for me: keeping the roller blinds closed all day, consistently keeping the bedroom cool, and taking 5-HTP when I notice my thoughts won't settle.

What I don't underestimate: fixed sleep times, even on weekends. It sounds uncool, but it makes a real difference to my sleep quality during the week.

And for all those in menopause who are also struggling with hot flashes: The combination of Siberian Rhubarb and consistent sleep hygiene has received a lot of positive feedback in our community.

Conclusion

Poor sleep in summer is no coincidence and no weakness; it has clear biological causes: too warm, too bright, too much stress. The good news: most of these causes can be influenced.

A cool bedroom, reduced light in the evening, fixed times, and targeted supplements like 5-HTP or magnesium can collectively make a real difference. As always, the key is not to do everything at once, but to implement one change at a time and observe what works.

Sources

1. Byerley WF, Judd LL, Reimherr FW, Grosser BI. 5-Hydroxytryptophan: a review of its antidepressant efficacy and adverse effects. J Clin Psychopharmacol. 1987;7(3):127-37. PMID: 3298325.
2. Abbasi B, Kimiagar M, Sadeghniiat K, Shirazi MM, Hedayati M, Rashidkhani B. The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial. J Res Med Sci. 2012;17(12):1161-9. PMID: 23853635.
3. Zisapel N. New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation. Br J Pharmacol. 2018;175(16):3190-3199. doi: 10.1111/bph.14116. PMID: 29318587.
4. Langade D, Kanchi S, Salve J, Debnath K, Ambegaokar D. Efficacy and Safety of Ashwagandha (Withania somnifera) Root Extract in Insomnia and Anxiety: A Double-blind, Randomized, Placebo-controlled Study. Cureus. 2019;11(9):e5797. doi: 10.7759/cureus.5797. PMID: 31728244.