Japan Data

It’s Hot Out There! Japan Meteorological Agency Warns of “Disaster-Level” Heat

Society Lifestyle

Japanese summers have been sweltering in recent years. The 10 hottest temperatures reached in Japan were almost all recorded since 2000—and several new records were set in 2018 alone.

The Japanese archipelago has been blanketed by a heat wave in July. The Japan Meteorological Agency reported that on July 23 Kumagaya in Saitama Prefecture recorded a temperature of 41.1 degrees, setting a new record high for all of Japan—the first in five years. That same day the city of Ōme in western Tokyo set its own record high of 40.8 degrees, marking the first time in recorded history for a location within Tokyo to reach a temperature of over 40 degrees. Tajimi in Gifu Prefecture also reached a temperature of 40.7 degrees twice this month, on July 18 and 23.


According to the JMA the Pacific high-pressure system over Japan has led to extended high temperatures. The temperatures for July are among the hottest since statistics began to be kept in 1961. Average mid-July temperatures this year exceeded the annual average by 4.1 degrees in the Kantō-Kōshin area, 3.6 degrees in the Tōkai area, 3.4 degrees in the Kansai area, and 3.1 degrees in the Chūgoku area.

Most of Japan’s highest temperatures were recorded since 2000, including five set in 2018 alone.

Highest Temperatures on Record in Japan

1 Kumagaya, Saitama 41.1 July 23, 2018
2 Shimanto, Kōchi 41.0 August 12, 2013
3 Tajimi, Gifu 40.9 August 16, 2007
3 Kumagaya, Saitama 40.9 August 16, 2007
5 Ōme, Tokyo 40.8 July 23, 2018
5 Yamagata, Yamagata 40.8 July 25, 1933
7 Tajimi, Gifu 40.7 July 23, 2018
7 Tajimi, Gifu 40.7 July 18, 2018
7 Kōfu, Yamanashi 40.7 August 10, 2013
10 Mino, Gifu 40.6 July 18, 2018
10 Kōfu, Yamanashi 40.6 August 11, 2013
10 Katsuragi, Wakayama 40.6 August 8, 1994
10 Hamamatsu, Shizuoka 40.6 August 4, 1994

Created by Nippon.com based on materials published by Japan Meteorological Agency (shaded areas are for 2018).

In a July 23 press conference, JMA meteorologist Takekawa Motoaki, called on the public to take due caution to safeguard their health, particularly to prevent heatstroke: “This level of heat is unprecedented for almost all regions of Japan and poses a danger to life. We look on this heat wave as being a type of natural disaster.”

According to the Ministry of Internal Affairs and Communications’ Fire and Disaster Management Agency, during the one-week period from July 16 to 22, a total of 22,647 heatstroke victims in Japan were provided emergency transportation. This is the highest number of persons to be transported by ambulance in one week since such data was first kept in 2008. The number of fatalities among those transported was also the highest on record, at 65 persons.

(Translated from Japanese. Banner photo: © Pixta.)

weather heat wave temperature heatstroke