A heat wave that has already killed dozens and sickened thousands in Japan reached another torrid milestone Friday as the nation’s capital, Tokyo, suffered an unprecedented eighth consecutive day of extreme heat.
Tokyo reached 37.7 degrees Celsius (99.9 degrees Fahrenheit) Friday, marking its eighth straight day of highs at or above Japan’s “extreme heat” threshold of 35 C (95 F). An analysis of Japan Meteorological Agency data, conducted by The Weather Channel, confirmed that the previous record was just four consecutive days sent on five different occasions between 1978 and 2013. Records began in central Tokyo in June 1875.
The torrid late-morning reading also marked central Tokyo’s highest reported temperature since August 2013. The city’s all-time record high remains 39.5 C (103.1 F) set July 20, 2004.
The toll from Japan’s ongoing heat wave accelerated last week, boosting the year’s official tally to 55 heat-related deaths and sending more than 11,000 to the hospital according to new government figures released Tuesday.
According to Japan’s Fire and Disaster Management Agency, 25 people died from heat stroke and other heat-related illnesses nationwide during the week of July 27 through Aug. 2. It was by far the deadliest week so far this year in Japan, nearly equaling the death toll of 30 in the preceding three months combined.
Public broadcaster NHK said another 5 heat deaths were confirmed Wednesday in Japan, in addition to 7 unconfirmed heat deaths.
The toll seems likely to rise even further as more deaths are officially attributed to the heat. NHK, citing local authorities, said heat-related illnesses are suspected of causing 68 deaths in Tokyo alone between July 11 and Aug. 4. The official national count of 55 only includes two deaths in Tokyo through Aug. 2.
The number of people sent to hospitals for heat-related illnesses also skyrocketed, reaching 11,637 when excluding the 25 deaths. This was more than double the figure for the same period in 2014. Since April 27, more than 35,000 people have been hospitalized due to hot weather in Japan. Of those, 855 have required at least three weeks of hospitalization due to the severity of their illness.
The heat has spared no region of the country. Heat-related deaths have been reported in 29 of Japan’s 47 prefectures, and each of the 47 prefectures has reported at least 100 heat-related illnesses.
The greatest concentration, however, has been in the nation’s urbanized areas – in part due to weather and in part simply due to larger populations. The Greater Tokyo area accounts for 19 of the 55 heat deaths this year, with Saitama prefecture suffering the highest death toll (nine) of any single prefecture. Tokyo proper leads the casualty count with 3,037 people affected by the heat, including two deaths.
Japan’s aging population is particularly vulnerable to the heat. Just over 49 percent of this year’s illnesses have involved people at least 65 years old. Children account for about 15 percent of the total, with adults ages 18 to 65 constituting the rest of the total.
The heat has expanded in recent days. According to data from the Japan Meteorological Agency, 223 of the nation’s 928 temperature observation sites recorded a high of at least 35 degrees Celsius (95 degrees Fahrenheit) on Saturday (Aug. 1), and more than two-thirds of the observation network hit at least 30 C (86 F).
Aided by abundant sunshine and a dearth of thunderstorm activity, more than 81 percent of JMA’s observation network hit the 30 C mark Tuesday, the highest figure since Aug. 22, 2012. The heat spread even further Wednesday, when 822 out of 928 sites reached 30 C, a level not matched since Aug. 6, 2010.
The heat even spread to the normally cool shores of Hokkaido, the northernmost of Japan’s four main Islands. The city of Nemuro reached an all-time record high of 33.6 C (92.5 F) Wednesday, topping the previous record of 33.0 C (91.4 F) set Aug. 6, 1960. Records in Nemuro date all the way back to 1879, making this an especially significant record climatologically.
Arguably the epicenter of the heat has been in the northern suburbs of Tokyo, which are among the hottest regions of the country owing to their low elevation, long distance from the coast and southerly latitude – a rare combination in Japan.
The city of Tatebayashi in Gunma prefecture recorded its 13th consecutive day of temperatures 35 C or higher on Wednesday, reaching 39.8 C (103.6 F). That’s the highest temperature recorded anywhere in Japan this year, according to JMA, and ties for the 25th-highest daily high temperature ever recorded in Japanese history.
In Japan, a day with temperatures reaching or exceeding 35 C (95 F) is known as a mōshobi, written as 猛暑日 and meaning “extremely hot day.” It’s likely no coincidence that the first character of that term is also the first character of Japan’s highest category of typhoon – mōretsu, written as 猛烈 and meaning “violent.”
The latter term was applied to Super Typhoon Soudelor when it peaked in intensity Monday. The typhoon impacted Japan’s southernmost islands on Friday, but was too far south to bring any heat relief to the mainland.