Japan experienced its hottest summer this year.

According to the Japan Meteorological Agency, the average nationwide temperature observed from June to August was 2.36 degrees Celsius above the seasonal norm.

This summer's average was the highest since recordkeeping of these statistics began in 1898 and 0.6 degree more than the previous record of 1.76 higher than the mean, set both in 2023 and 2024.

Among 153 weather observation points across Japan, record-high temperatures were marked at 132 locations, or over 80 percent of the total.

Officials said factors that contributed to the high temperatures likely include westerly winds flowing further north than usual, making it easier for warm air to cover the skies over Japan.

Meanwhile, the land ministry is calling on people in the Kanto region in eastern Japan to conserve water.

Officials said the amount of water in reservoirs serving the area has fallen under 50 percent due to scorching heat and little rain.

At Yamba Dam in particular, the water storage rate has declined to about 22 percent.

This is the lowest level recorded at Yamba Dam since it began operating in 2020.

Submerged structures such as old railway bridges and roads became visible.

Low rainfall has continued over rivers serving the Kanto region since June, with the water storage rate at nine dams upstream of the Tone River at 45 percent as of September 1.

The amount is about 60 percent of the average storage rate at these reservoirs.

Weather officials said they expect sunny days to continue, with precipitation likely to be around or below average.