Sleeping well has become a luxury to be achieved, at least in summer. In fact, when the thermometer does not drop even after sunset, the human body struggles to cool down and the natural rest mechanism short-circuits. The study “Climate Change is Costing People Sleep”, conducted by the independent organization Climate Central, measured the consequences of global warming on health, analyzing 1,338 cities and comparing data from the period 2020-2025 with the findings from the 1970s. The result is a clear picture: pollution from human emissions is gradually eroding our sleep hours.
The global map of heat insomnia
The numbers collected by Climate Central outline a widespread crisis. Between 2020 and 2025, the global average of hours of sleep lost due to high nighttime temperatures reached 56 hours per year per person, corresponding to approximately seven full nights. Of these, approximately six hours (over 10%) are directly attributable to the influence of climate change. The most drastic impacts are recorded in the Middle East: in Saudi Arabia, Oman and the United Arab Emirates, between 55 and 87 hours per year are lost, with peaks of 16 hours due exclusively to anthropogenic warming.
The scenario is also critical in southern India, in south-east Asia (up to 91 hours lost) and in West Africa, where in countries such as Niger, Nigeria and Burkina Faso the drop exceeds 65 hours. In the United States, the average is 36 hours lost, but states such as Arizona, California, Florida and Nevada are close to nine hours lost per year due to altered climate alone.
The impact in Italy and historical comparison
Italy records even worse numbers than the global average. In Milan, out of the 35 hours of sleep lost annually due to the heat, 7 hours (20%) depend on climate change. Similar data characterize Rome and Turin (33 hours in total, 6 attributable to the climate), while Palermo reaches 43 hours lost, of which 8 due to global warming. The historical comparison highlights a clear acceleration: from the 1970s to today, the share of sleep taken away by heating has at least doubled in 1,335 cities out of 1,338 and even tripled in 840 urban centres. Numbers that officially establish how record temperatures are not a simple “seasonal inconvenience” but a true global health emergency.
