While the eastern U.S. and Canada have recently seen below-normal temperatures, a major summer heat wave has been the story in eastern China since early July.
Shanghai saw its hottest July in 140 years as temperatures soared to 100ºF or higher for 10 straight days between July 23 and August 1. The coastal city reached 95ºF (35ºC) or higher on 25 days last month, 14 of which exceeded 100ºF (37.8ºC).
This week, Shanghai eclipsed its all-time record high temperature set barely two weeks ago. The Shanghai Daily reports that the city’s meteorological bureau recorded a temperature of 105.4ºF (40.8ºC) on August 7, which breaks the previous record of 105.1º (40.6ºC) from both July 26 and August 6, 2013. Prior to this year, the all-time high at Shanghai’s Xujiahui weather observatory was 104.4ºF set in 1934.
High humidity and trapped urban heat have also kept overnight temperatures several degrees above normal. On July 29, Shanghai only dropped to 88ºF (31ºC). Normal high and low temperatures in the metropolis are about 91 and 78 degrees, respectively, this time of year.
Other major cities in eastern and southern China have been as hot, if not hotter, than Shanghai. The Global Times reports that China’s National Meteorological Center issued a red temperature alert – its highest-level heat warning – for the 14th straight day.
High temperatures on August 7 broke records at 130 weather stations across the country, and 30 stations measured their all-time highest temperatures on record this year.
Last week, Weather Underground’s Christopher Burt wrote that Ningbo City, south of Shanghai, reached 108.9ºF (42.7ºC) on July 26 – the warmest temperature ever measured along China’s eastern or southeastern coast. Asian news outlets are reporting the temperature on Wednesday reached an even higher 110.3ºF (43.5ºC) in nearby Fenghua, which would also be a record for the surrounding Zheijiang Province.
The prolonged spell of scorching temperatures is a result of stationary high pressure off the eastern coast, which has prevented tropical moisture from delivering normal summer rainfall. Drought conditions have developed in southern China, and low soil moisture has helped boost air temperatures to record levels.
The longer-term effects of rapid urbanization, decreased vegetation, and global warming are also at play, as experts at China’s Meteorological Center have explained to the local press.
As eastern and southern China wilt under the heat, the normally arid northwestern provinces have faced major flooding and above-average rainfall. The Xinhua news agency writes that July precipitation measured 12.9 inches (328.1 mm) in China’s northern Shandong province, a 50-year high.
The inverted weather pattern this summer is due to the jet stream stream staying parked to the north, which has kept rain from reaching China’s southern and coastal regions.
For the millions of heat-weary residents in China’s major coastal cities, the extended hot spell will continue for at least another week. A silver lining is that temperatures will slowly moderate into the mid-90s after the weekend. Yet rainfall remains absent, as tropical storm systems, typical for this time of year, steer clear of the East China Sea.