Photo/Illutration The status of heat stroke alerts issued on July 17 ( From the JMA website)

A record-high temperature of 39.7 degrees Celsius for Japan this year recorded in Kiryu, Gunma Prefecture, on July 16 was only a preview of more sweltering weather to follow across the nation. 

The Japan Meteorological Agency and other authorities issued a heat stroke alert for 32 prefectures on July 17, a significant increase from the previous day. The advisory includes Fukushima, Tokyo, Aichi, Osaka and Fukuoka prefectures.

This is the largest number of alerts issued this year, with officials calling for caution amid the dangerously hot weather as the nation marks the end of a three-day holiday weekend. 

A Pacific high pressure system to the south of Japan has extended from Kyushu to Hokuriku, and the Tibetan high pressure system on the continental side has strengthened on the Japanese side, resulting in a "double high" near Japan and the continuing heat wave. 

The highest temperatures expected for July 17 include 37 degrees in Tokyo, 38 degrees in Nagoya, 35 degrees in Osaka and 36 degrees in Fukuoka. 

Meanwhile, in Akita Prefecture, where heavy rain has been falling due to a stagnant seasonal rain front, the front has weakened, but the inflow of warm, moist air is expected to continue, resulting in the threat of heavy localized rainfall.

The one-hour precipitation amounts expected for the next two days are 20 millimeters along the Akita coast and up to 20 mm inland. The 24-hour precipitation amounts forecast by 6 a.m. on July 18 are 50 mm along the coast and 50 mm inland.