The Japanese government warned of possible power shortages Monday in the Tokyo region, asking people to conserve energy as the country endures an unusually intense heat wave.
Weather officials have announced the earliest end to the annual summer rainy season since the Japan Meteorological Agency began keeping records in 1951. The rains usually temper summer heat, often well into July.
The economy and industry ministry urged people living in the region serviced by the Tokyo Electric Power Co. to conserve power in the afternoon, especially when demand peaks at 4-5 p.m.
Over the weekend, the temperature in central Tokyo rose above 35C, while the city of Isesaki, northwest of the capital, saw a record 40.2C. That was the highest temperature ever recorded in June for Japan.
June marks the start of summer in Japan, with temperatures typically staying below 30C during the month.
In a statement on Sunday, the ministry said that excess generating capacity for electricity was expected to drop to 3.7% on Monday afternoon in Tokyo and eight surrounding prefectures. It views a buffer of 3% as necessary for stable power supply.
The government asked people to turn off unnecessary lights for three hours from 15:00 Tokyo time while "properly using air conditioning and hydrating during hot hours".
As of mid-afternoon on Sunday, 46 people in Tokyo had been taken to hospital with suspected heat stroke, public broadcaster NHK said.
A 94-year-old man in Kawagoe city, 20 kilometres (12 miles) northwest of Tokyo, died of suspected heat stroke after he was discovered unconscious in his non-air conditioned room on Saturday, NHK said.
Isezaki city, 85 kilometres (53 miles) northwest of Tokyo, logged Japan's highest temperature ever for June on Saturday, breaking above 40 degrees Celsius (104 degrees Farenheit), according to the Japan Meteorological Agency.
Power supply is relatively tight after Japan idled most of its nuclear reactors after 2011 meltdowns in Fukushima. It also has been closing down old coal plants to meet promises for reducing carbon emissions.
Japan also faces a potential shortage of fossil fuel imports amid sanctions against Russia over its invasion of Ukraine.
