Japan's weather authorities call this summer's heat 'abnormal'

Japanese weather authorities have called this summer "abnormal," with days of extremely high temperatures observed across the country since early July.

Japan has had a number of days when daytime highs topped 38 degrees Celsius since late last month. A high of 40 degrees was observed in the city of Date, Fukushima Prefecture, on August 5, and also in the city of Komatsu in Ishikawa Prefecture on August 10.

The average temperature in the north for late July was at the highest since record-keeping began in 1946. Coastal areas along the Sea of Japan in the country's east and west logged record high average temperatures for early August.A group of experts attending a Meteorological Agency meeting on Monday analyzed extreme heat recorded in late July.They attributed the heat to jet streams above Japan that they say were shifting further north this summer than usual.

They said this resulted in a warm high-pressure system covering Japan and surrounding areas, coupled with another high-pressure system in the Pacific that extended below unusually deep.

The experts said two tropical storms in late July and August pushed up temperatures in the Sea of Japan coastal areas to over 38 degrees for several days in August. They said the two storms constantly brought warm, moist air around Japan. They added that the foehn phenomenon was also a factor. The phenomenon caused air with less humidity and higher temperatures when a mass of hot and humid air descends from a mountain.

The experts also looked at extreme heat this year in northern Japan. They said it was due to warmer ocean temperatures in the area.

The researchers expect the average temperature for this summer in Japan to be the highest since officials began collecting statistics in 1898.

University of Tokyo Professor Nakamura Hisashi, chair of the panel, said air temperatures in Japan could hardly cool down due to record high ocean temperatures around the country. He said global warming is another factor in the scorching temperatures.

Nakamura said temperatures have shot up noticeably since the end of this year's rainy season. He said the extreme heat had serious implications for society, in the form of ailments such as heatstroke. He also said this summer in Japan has experienced "abnormal weather."