According to a new study from Climate Central, a nonprofit that specializes in climate change research and attribution science, more Americans are losing sleep due to the heat than ever before. Their new study found a correlation between warm summer nights and sleep loss. And ABC13 Meteorologist Elyse Smith has previously reported on how Houston's warming nights have led to longer heat waves, hotter afternoons and an increase in heat-related illness.
The new study from Climate Central details how climate change is impacting people's sleep. Researchers were able to quantify how much sleep is lost when nighttime temperatures are well above normal for a specific country, region, and even city per year. The average was taken from the years 2020 to 2025. Across the United States, Americans are losing an average of 2 to 14 hours a year due to the heat. And for cities along the Gulf Coast, like Houston, it's on the higher side. Houstonians are losing an average of 7 to 9 hours of sleep per year thanks to our warming summer nights.
The time of year when Houstonians could be impacted by these hot nights is typically mid-to-late July through August. This is when morning low temperatures could be well above the norm, potentially reaching as high as 80 degrees or more. The climatological average of a summertime morning low temperature is usually somewhere in the mid-70s. So a morning low temperature of even 79 degrees and up is not normal. But those kinds of steamy mornings are becoming more frequent.
For the same timeframe in which this study took place, Houston experienced 116 mornings with a low temperature of 80 degrees or greater. That's an average of 23 per summer, though that average was heavily influenced by our record-hot summer of 2023. These warmer mornings can lead to even hotter afternoons, prolong heat waves, and impact our health, including our sleep.
Climate Central also applied the same concept to other countries across the globe. People in cities in the Middle East can lose 55 to 87 hours of sleep a year because of how hot it can be at night there. Closer to home, for Mexico and Central America, it averages around 36 hours of sleep loss per person a year. Now another factor to consider with this is access to ways to stay cool, like A/C and overall quality of life. The global average rounds out to be around 56 hours of sleep loss a year due to these hot nights, which Climate Central attributes to the warming global temperatures.