Trouble Sleeping in Warmer Weather? You're Not Alone

Sleep is something that eludes me at times. These last few nights, with the sunny days and warm nights, rest has been particularly tricky for me to find. Looking through a journal, I noticed that around this time last year, I had also danced with a bout of insomnia. And the year before. I couldn't quite mark where the pattern began. I wondered, do other people have this pattern?

The answer is yes.

A study utilizing an actigraph—a sort of watch that measures activity and sleep patterns—with 97 participants living with episodic migraines found that warmer weather was associated with lower sleep efficacy (Li et al., 2020). Another study of 216 participants found a correlation between shorter sleep duration and longer days in spring and summer (Mattingly et al., 2021). Finally, a new systemic review of five studies noted a correlation between warmer weather and poorer sleep quality (Chevance et al., 2024), and found that individuals with a tendency toward insomnia are particularly susceptible.

As we fall asleep, our temperature naturally drops. Warm temperatures can interfere with this process, making it harder to fall asleep and interfering with sleep quality. Lack of sleep can be a powerful trigger for mental health symptoms; as well, these sleep changes may underlie some of the links between spring and summer months and mania in bipolar disorder.

Outside of planning a trip to Antarctica, what can you do to deal with these changes? Here are three ideas:

1. Cool down with a shower before sleep. A shower can help you to cool down your body temperature. When we habitually do something shortly before sleep, we can build an association between that activity and sleep. A routine of showering before bed could be a part of that routine.
2. Exercise early in the day. While research shows that exercise correlates with improved sleep regardless of the time of the day (Goldberg et al., 2024), exercise does lift our body temperature. If you can exercise early in the day during the heat, you are more likely to get the maximum benefit.
3. Keep a consistent sleep window. With longer days as we reach summer, it can be tempting to stay up later sometimes. Still, going to sleep and waking close to the same times each morning and night sets a rhythm that can make it easier to fall asleep.

Warmer weather can decrease sleep quality. Still, by taking steps to stay cool, being active during the day, and keeping consistent with sleep timing, it is possible to stack the odds in favor of a good night's sleep.