This month is likely be the hottest August that Japan has experienced since 1946 when regional temperature data become available after the end of World War II, weather agency officials said, while linking this phenomenon with global warming.
Under the Japan Meteorological Agency's zoning of the nation into four regions, all but one covering the southwestern island chains of Amami and Okinawa are expected to register record-high average monthly temperatures, according to a preliminary report.
Also, 84 of the 154 nationwide meteorological observatories are likely to see their highest monthly averages, including figures that tie past records, according to the agency's data.
The agency said the record heat might be attributable to a long-term trend of global warming, as well as high atmospheric pressures from the Pacific Ocean and continental Asia.
The temperatures exceeded the average year by 2.6 degrees celcius in northern Japan, a zone covering Hokkaido and Tohoku, 2.2 degrees celcius in eastern Japan that ranges from Kanto-Koshin to Tokai, and 2.1 degrees celcius in western Japan stretching to Kyushu.
Some of the nation's major cities saw monthly averages rising to their highest on record, Kyoto saw 30.0 degrees celcius, Osaka 30.4 degrees celcius, Hiroshima 30.3 degrees celcius and Fukuoka 30.4 degrees celcius. In Tokyo, the average temperature was 2.4 degrees celcius higher than the typical year at 29.5 degrees celcius, according to the agency.