The temperature hit 40 degrees Celsius in Date, Fukushima Prefecture, on Saturday — marking hottest day this year in Japan — as a heat wave continued to scorch the country.

The Meteorological Agency said the mercury had hit exactly 40 degrees at 2 p.m. in the city. While Tohoku region, where Fukushima is located, has traditionally seen cooler temperatures than some other parts of the country, dangerous heat has hit life-threatening levels across a broad of Japan, according to the agency.

Temperatures in Sakai, Fukui Prefecture, as well as the city of Fukushima, both rose above 39 degrees around 2 p.m., the agency said. As of 2 p.m., 225 locations had experienced an "extremely hot day," meaning that the highest recorded temperature there surpassed 35 degrees.

Heat stroke alerts were in effect Saturday for 41 of Japan's 47 prefectures. Officials have urged people to stay indoors as much as possible and take precautions to prevent heat stroke in the event venturing outside is required.

In Japan, unrelenting heat waves — combined with suffocating humidity — have been weighing particularly heavily on the nation’s 36 million people age 65 and over, who are at much greater risk of severe illness and death.

Meanwhile, Typhoon Khanun was set to again approach Okinawa's main island and parts of Kagoshima Prefecture's Amami islands, after the "very unusual storm" made a sudden, sharp turn to the east on Friday evening after leaving at least two dead.

The storm was expected to bring high waves and storm surges through Sunday, the weather agency said. It was forecast to approach western Japan at the beginning of next week and could remain in the area through Thursday.