Americans that live in colder states are more likely to sleep longer

As we slouch toward the end of a sticky summer, Americans will be looking forward to finally turning off their AC and getting out their comforters with the approach of autumn (though by Starbucks’ seasonal standards, we’re already a week in).

Pumpkin spice notwithstanding, one of the best things that colder temperatures signal for many is a better night’s sleep.

The cool side of the pillow

Last month, updates were published from an ongoing research project, funded by Apple in collaboration with the American Heart Association and Brigham and Women’s Hospital, that uses Apple Watch data from over 61,000 adults to provide insights on factors that affect heart health, including sleep.

Overall, the study showed that most Americans aren’t getting enough shut-eye: the average sleep duration for US adults worked out to be 6 hours and 40 minutes, per Axios, short of the recommended seven to nine hours. It also found that the average bedtime for Americans (or at least when they get off their devices) was about 11:37 p.m.

However, overlaying the results with the average annual temperatures in each US state last year presented a clear correlation: residents in colder states tended to sleep more.

Plotting average sleep duration with each state’s deviation from the national mean temperature showed that warmer states — such as Louisiana, Texas, and Florida — trended with having shorter sleep lengths. Hawaii, known for its tropical climate, saw participants get the least sleep of any state at 6 hours and 31 minutes, despite having the earliest bedtime (11:06 p.m.).

Generally, states with below-average temperatures, like Colorado and Wyoming, reported the longest slumbers — bar notable exceptions like extremely cold Alaska and unusually sleepy D.C. In fact, while D.C. residents had the third-longest average sleep duration in the country, at 6 hours and 47 minutes, they also went to bed the latest (11:56 p.m.).