Japan swelters through ‘abnormal’ autumn, with warnings of more heat to come

<span>Photograph: Richard A Brooks/AFP/Getty Images</span>
Photograph: Richard A Brooks/AFP/Getty Images

Matsutake mushrooms and persimmons have appeared on supermarket shelves, along with seasonal beers and sakes. In Tokyo neighbourhoods, residents carry portable shrines through the streets at festivals to mark the end of summer, and children get ready for school sports days.

Autumn, though, has yet to make an appearance in Japan. Instead, experts are warning that the crisp, sunny days that usually offer relief at the end of a sweltering summer are still some way off, with one describing the weather as “abnormal”.

Japan experienced record-breaking heat this summer, with daytime highs exceeding 38C on some days, the public broadcaster NHK said, adding that “disaster-level” heat of 40C had been observed in two cities in early August.

Related: ‘Major disruptor’: El Niño threatens the world’s rice supplies

Based on measurements at 15 locations around the country from June through August, Japan’s summer was its hottest since 1898, when the meteorological agency started collecting data.

Tokyo has experienced 22 days this year when the mercury topped 35C – the agency’s definition of “extremely hot” weather – easily breaking the previous record of 16 days, set last year.

Even Sapporo, the country’s northernmost main city – and venue for a snow festival every February – experiencing three straight days over 35C in late August. Hokkaido Railway Company cancelled trains, fearing the heat could warp tracks, while some students were asked to study remotely rather than attend lessons in classrooms without air conditioners.

The ancient capital of Kyoto, known for its humid summers and bracing winters, saw a record 37 days of extreme heat.

People in Tokyo use umbrellas and parasols to seek relief from the heat while crossing a street outside Shinjuku station.
People in Tokyo use umbrellas and parasols to seek relief from the heat while crossing a street outside Shinjuku station. Photograph: Richard A Brooks/AFP/Getty Images

Conditions have eased since the start of September, but only marginally. Earlier this month, organisers of a marathon in the north-east city of Morioka terminated the race midway through after a large number of runners retired due to the heat, with one pronounced dead after being rushed to hospital.

Weather observation points across Japan have broken annual records for the number of extremely hot days, prompting the Mainichi Shimbun newspaper to ask: how long will this heat continue?

The answer will disappoint those desperate to escape the brutal heat. According to the meteorological agency, the combined effect of El Niño and global heating means that unusually hot weather will continue through to the end of the month and into October.

“Even if it’s not extremely hot, there is a possibility that high temperatures of around 30C will continue in October, so people need to be careful about heatstroke,” Takafumi Umeda, director of the agency’s Tokyo Climate Centre, said recently, according to the Mainichi.

The agency has also predicted a mild winter with less snowfall than usual – a forecast that will dismay businesses in resorts that usually attract large numbers of skiers and snowboarders.

One location is escaping the worst of the heat, however. In Katsuura, in Chiba prefecture east of Tokyo, the temperature did not rise above 35C throughout July and August – the 118th year in a row the coastal town had avoided extremely hot days.

Human-caused climate breakdown is supercharging extreme weather across the world, driving more frequent and more deadly disasters from heatwaves to floods to wildfires. At least a dozen of the most serious events of the last decade would have been all but impossible without human-caused global heating.