As tropical and hot nights — when the overnight temperature does not fall below 20°C — become more frequent worldwide, people’s sleep is paying the price.
Globally, the average person lost nearly 56 hours of sleep — equivalent to nearly seven nights’ worth of sleep — per year due to high temperatures during the 2020-2025 period, according to a new study by Climate Central.
Across nearly every city out of over 1,300 analysed, the amount of temperature-related sleep loss linked to climate change has at least doubled since the early 1970s. The highest level of sleep loss was in the Middle East and Southeast Asia, where people lost an average of between 55 and 91 hours per year.
In the early 1970s, people living in an average city of 500,000 residents lost about 46 hours of sleep per year due to night-time heat; by the 2020s, that rose to about 50 hours. Between 2020 and 2025, that number rose to 56, and climate change accounts for a larger share of that burden, the analysis found.
Where in Europe are people losing the most sleep?
