Climate change is causing people around the world to lose an average of about 56 hours of sleep each year due to hotter nights. This conclusion was reached by experts from the American organization Climate Central, who analyzed the impact of nighttime temperatures on sleep quality from 2020 to 2025. Bloomberg reports on the findings.

The researchers calculated that more than six hours of these losses — roughly one sleepless night per year — are directly linked to global warming caused by human activity. This is the first study in which the duration of lost sleep was quantitatively assessed based on data on nighttime temperatures and their effects on the human body.

The authors analyzed the situation in 1,338 cities around the world. It turned out that in 1,335 of them, sleep losses associated with climate change had at least doubled compared with the early 1970s. In 840 cities, this figure had more than tripled.

High nighttime temperatures have the strongest impact on residents of the Middle East. In cities in Saudi Arabia, Oman, and the United Arab Emirates, people lose from 55 to 87 hours of sleep per year, with 12–16 of those hours specifically linked to climate change.

In India and Southeast Asian countries, annual losses reach 78–91 hours, of which 8–9 hours are attributed to global warming. In West African countries, this figure exceeds 65 hours per year, with about 10–11 of those hours also explained by climate change.

In the United States, residents lose an average of about 36 hours of sleep per year because of hot nights. Researchers attribute about four hours of that time to climate change. This effect is most noticeable in the states of Arizona, California, Florida, and Nevada.

According to the study’s authors, rising nighttime temperatures are dangerous because the body recovers less effectively during sleep. While daytime heat can be partially offset with air conditioning or changes in daily activity patterns, warm nights significantly reduce the quality of rest and can negatively affect health.