Japan's record-setting coldest prefecture now lays claim to the nation's hottest temperature ever recorded in May, with the thermometer reaching 39.5 degrees in Saroma in northern Hokkaido at 2:07 p.m. on May 26.

According to the Japan Meteorological Agency (JMA), it marked the first time in its observation history that the temperature exceeded 35 degrees in Hokkaido in May.

Other parts of Japan's northernmost main island also broiled in the unseasonable heat, with the temperature hitting 38.8 degrees in Obihiro at 1:12 p.m., 38.7 degrees in Ashoro at 1:16 p.m. and 38.6 degrees in Ikeda at 1:20 p.m.

Temperatures higher than 30 degrees are also likely to be recorded in other areas of Japan. On the day, the temperature is expected to rise to 36 degrees in Kitami, Hokkaido, and Fukushima.

The highest temperature will also be around 35 degrees in Iwate, Yamagata, Saitama, Yamanashi, Gifu, Kyoto, Hyogo and Oita prefectures, and 33 degrees in central Tokyo.

The JMA issued a heat warning for wide areas from Hokkaido to Kyushu. The warning is issued when temperatures are expected to exceed 35 degrees.

The agency is urging people to drink water frequently and wear hats or caps to avoid suffering from heat stroke.