Weather officials in Japan say the country's average temperature this summer was the highest since records began 125 years ago.

The Meteorological Agency made the announcement on Friday.

The average temperature from June to August was 1.76 degrees Celsius higher than the 30-year average. In northern Japan, it was three degrees higher.

Niigata Prefecture's Itoigawa City recorded the country's hottest night ever on August 10, when the temperature did not fall below 31.4 degrees.

Nighttime record highs were observed in 248 locations nationwide.

Sea surface temperatures around Japan also rose one degree higher than the average. That's also the warmest since records began in 1982.

Last Monday, a panel of scientists working under the meteorological agency described this summer as "abnormal."

They attributed the hot weather to high-pressure systems that often spread across the country.