Heat defies tradition, rewrites record books

The Yomiuri Shimbun

According to traditional belief, Aug. 23 is "shosho," the day when summer's heat begins to wane, but conditions across the nation were still scorching on Monday.

At about 2 p.m., the temperature was 36.7 C in Nerima Ward and 35.1 C in Otemachi, both in Tokyo. At the same time, it was 35.4 C in Nagoya and 36.8 C in Osaka.

According to the Meteorological Agency, more "extremely hot" days--those that see temperatures of 35 C or more--are expected this week, especially in western Japan.

This week's peak temperatures are expected to be around 33-34 C in Tokyo, 32-35 C in Nagoya and 33-36 C in Osaka, all of which are about 2 C to 3 C higher than average for this time of year, the agency said.

The heat will continue into September, with higher-than-normal temperatures expected for that month. The agency forecasts that the temperature in early September will be 30 C or more in many regions.

From Aug. 11 to 20 this year, the average temperature in western Japan was 2 C higher than normal for that time of year. It was the region's highest average temperature for the period since records began in 1961.

In eastern Japan, the mid-August average was 1.8 C above normal, and was the second-highest on record for the region. Otemachi has now experienced nine extremely hot days this summer, the second-highest total for the area on record.

Osaka has seen 16 extremely hot days this summer, and 14 have been recorded in Nagoya.

According to the agency, the ongoing heat wave has been generated by a Pacific anticyclone from the continent that has covered the Japanese archipelago since Aug. 15, while another high pressure system from the continent hanging above it has prevented the air from cooling.

Another reason could be El Nino, which for almost a year until spring continued to transmit heat across the ocean and push up temperatures in the northern hemisphere.