In 2021 everyone in Japan 10 and older slept for an average of 462 minutes (seven hours and 42 minutes) per weekday. This is an increase of 13 minutes compared to the 2016 survey.
The survey is conducted every five years.
One caveat: Before 1996, the survey only tracked those 15 and older, but even this group registered more sleep in the latest survey.
Aomori prefecture residents got the most sleep, an average of 480 minutes (eight hours), followed by those of Kochi, 477 minutes; Akita, 476 minutes; and Kagoshima, 476 minutes.
Residents of Kanagawa prefecture, next to Tokyo, were the most sleep deprived, getting 454 minutes of shut-eye, followed by those of Tokyo, 455 minutes; Shizuoka, 458 minutes; and Hyogo, 458 minutes.
The prefectures with the heaviest sleepers were those where agriculture is the main industry and where sprawling urban jungles have not taken shape. In these prefectures, a large percentage of the population lives close to the workplace and therefore has short commutes, according to a recent survey.
An official from Aomori prefecture – many parts of which are dominated by agriculture – noted that the lifestyles in these areas are distinct from those in big cities, with limited after-work entertainment options and early bedtimes.
People in metropolitan areas, where many residents have to put up with long commutes, averaged fewer minutes of slumber. Residents of the nine prefectures with commuting times under 30 minutes slept for an average of 471 minutes per weeknight, while those of the eight prefectures with times exceeding 40 minutes averaged 459 minutes.
Since the 2016 survey, Saitama prefecture sleepers gained the most winks, an average of 23 minutes worth. Chiba prefecture snoozers gained an average of 20 minutes, and Kanagawa prefecture dozers kept dreaming for an average of 13 more minutes. All three of these prefectures border Tokyo.
In the latest survey, the dwellers of Fukuoka (19 minutes), Aichi (18 minutes), Osaka (12 minutes) and Tokyo (12 minutes) – all of which host major metropolitan areas – gained more than 10 minutes. The increases were highest in prefectures with larger numbers of bedroom communities.
The rapid adoption of teleworking during the Covid-19 pandemic is believed to have led to the increase in sleep time. Another sign of this can be seen when looking at sleep duration by age group, with working-age individuals gaining more sleep than minors and the elderly.
This has led to a reduced difference between Aomori prefecture slumberers, who boast the most minutes in bed, and those of Kanagawa prefecture, who spend the least amount of time on their futons. The spread is now 26 minutes, down from 39 in 2016.
According to a 2021 survey by the Organization for Economic Cooperation and Development (OECD), Japanese sleep an average of seven hours and 22 minutes. This is the shortest duration among the member countries and almost an hour less than the OECD average of 8 hours and 24 minutes.
An increase in sleep duration could potentially lead to improved productivity, but professor Toshihiro Okubo of Keio University warns that “it is highly likely that the decrease in commuting and working hours during the pandemic has temporarily lengthened sleep duration.”
Okubo also notes that “working hours in Japan are traditionally long, with many meetings, administrative tasks and chores. We are even more short-staffed now. Unless this changes, sleep duration will not increase.”
The most recent data, Okubo noted, shows more people returning to the office.