Survey in Japan Finds Majority of People Sleep with AC on in Summer

In Japan’s hot summers, more than half of people leave the air conditioner on through the night.

Keeping Cool

A survey in Japan found that 92.5% of the respondents have an air conditioner in their home, and that 38.1% of them always turn it off when going out during the summer. The survey was conducted by market research firm Cross Marketing, targeting people nationwide aged 20 to 69, with a total of 1,100 valid responses received.

Among those surveyed, 56.4% said that they leave their air conditioner on throughout the night. All age groups were above 50%, with especially high rates among those in their twenties and thirties, at 59.0% and 58.2%, respectively. With Japan continuing to face severe heatwaves every summer, the habit of cooling down a room even when outside the home or asleep is becoming the norm among more and more people.

According to the survey results, the most common temperature setting is between 26.0 ° and 27.5 ° Celsius during the day, and between 27.0 ° and 28.5 ° at night.

Data Sources

Report on summer use of air conditioning (Japanese) from Cross Marketing, 2025.