CLIMATE OF CHINA: PRECIPITATION, REGIONAL AND SEASONAL VARIATIONS

WEATHER IN CHINA

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Summer weather scene Before the Western Han dynasty (206 B.C. to A.D. 8) the climate in northern China was warmer than it is now and better for raising crops. The Chinese began using weather cocks and vanes very early and were probably the pioneers of wind direction devices. At least as early as the first century B.C., the Chinese recorded "wind seasons," and used kites to record the speed and direction of the 24 seasonal winds.

"When the weather is unusual people do unusual things," goes a Chinese proverb. During unusually mild winters in Beijing weather forecasters sometimes say cold weather is on the way to prevent the proverb from becoming true.

In December 2007, the Chinese government declared that weather forecasts were “state secrets” and said it would clamp down on illegal weather acquisition by foreigners. Violators included an illegal weather station set up by a Japanese company near a power station and a weather observation post near the Olympics yachting venue in Qingdao, which also happened to be near a military harbor.

Chinese meteorologists go about their jobs in a very no nonsense way. An Australian weatherman known for his comic, lighthearted broadcasts told the Los Angeles Times that some Chinese weatherman took offense to his style. “The Chinese take their weather seriously,” he said, “They wanted to know how I could joke about a topic that was likely to kill people.”

Climate in China

China is a big country and the climate varies greatly from region to region. There are places with bitterly cold winters as well as ones with scorching summers and everything in between. Wintertime in Inner Mongolia brings temperatures of -40°C (-40°F), while summer temperatures in Turpan, ‘the hottest place in China’, can hit 47°C (117°F). Beijing and Shanghai and most of China are very hot and humid in the summer; climate differences are more variable in the winter. Spring and fall generally have the most pleasant weather.

According to the Columbia Encyclopedia: “To the extent that a general statement about the climate of such a large country can be made, China may be described as wet in the summer and dry in the winter. Regional differences are found in the highlands of Tibet, the desert and steppes of Xinjiang and Inner Mongolia, and in China proper. There the Qingling Mts. are the major dividing range not only between semiarid northern China and the more humid central and southern China but also between the grain-growing economy of the north and the rice economy of the south. [Source: Columbia Encyclopedia, 6th ed., Columbia University Press]

Most of China is in the northern temperate zone. and experiences four seasons. Only the southernmost portions of the Provinces of Yunnan and Guangdong, and the Shuang Autonomous Region of Guangxi lie within the tropics. A monsoon climate is a major influence in the south, but the north and west have a typical continental climate, except that winters are extremely dry and summers quite rainy.

Monsoon winds, caused by differences in the heat-absorbing capacity of the continent and the ocean, dominate the climate. Alternating seasonal air-mass movements and accompanying winds are moist in summer and dry in winter. Tremendous differences in latitude, longitude, and altitude give rise to sharp variations in precipitation and temperature within China. Although most of the country lies in the temperate belt, its climatic patterns are complex. [Source: Library of Congress, 1987]

China's Summer Rainy Season

There is an alternating wet monsoon in the summer and a dry monsoon in winter. North China and southward are affected by the seasonal cold, dry winds from Siberia and the Mongolia Plateau between September/October and March/April. Summer monsoon winds bring warm and wet currents into South China and northward in June and July. There are often vicious storms, heavy rains, floods and landslides in the early summer. Heavy storms over Eastern and Southern China and the Yangtze River Basin are the result of a western Pacific subtropical high, a pressure system that carries warm air from south to north every summer

Plum Rains, or Yellow Plum Rains, is the nickname given to the annual rainy season in South and East China. The name is used mainly in the Yangtze River basin. The Chinese monsoon affect Taiwan and extend into Japan where it is called Bai-u. When its rains first strike the Yangtze River basin in June or July, the plums have turned yellow and ripened, hence the name.

Summer monsoons were abnormally strong in 2020 but was is not clear whether climate change was a a reason. It has been predicted that climate change will bring more severe and frequent droughts and floods. The occurrence of heavy rains has risen by about 3.8 percent per decade since 1931, according to China’s Blue Book on Climate Change (2019). That’s a total increase of more than 20 percent, said Junyan Liu, climate and energy campaigner for Greenpeace East Asia,“Very severe change.” [Source: Alice Su, Los Angeles Times, July 29, 2020]

Rain, Precipitation and Storms in China

20080317-CHN290992190801~Winter-A-Frozen-River-Landscape-with-a-Lady-.jpg
Winter weather scene Annual precipitation varies significantly from region to region, with a high of 1,500 millimeters annually along the southeastern coast and a low of fewer than 50 millimeters in the northwest. Generally, southern China is relatively wet and northern China is largely dry. Rains tend to fall heaviest near the coasts and in the south and where mountains lift clouds pushed in by southeastern winds. South of the Yangtze River rainfall generally varies between 100 and 190 centimeters (40 and 75 inches) a year. North of the Yangtze rains diminish from 63 centimeters (25 inches) to 25 centimeters (10 inches) as one travels north. Rain also diminishes towards the west. In the Gobi Desert in Inner Mongolia and the Tarim Basin in Xinjiang the annual rainfall is less than 10 centimeters (four inches) in many places.

The advance and retreat of the monsoons account in large degree for the timing of the rainy season and the amount of rainfall throughout the country. Differences in latitude, longitude, and altitude give rise to sharp variations in precipitation within China. Precipitation varies regionally even more than temperature. China south of the Qinling experiences abundant rainfall, most of it coming with the summer monsoons. To the north and west of the range, however, rainfall is uncertain. The northwest has the lowest annual rainfall in the country and no precipitation at all in its desert areas. [Source: Library of Congress, 1987]

Precipitation is heaviest in the south and southeast, with Guangzhou receiving more than 200 centimeters (80 inches), and diminishes to about 60 centimeters (25 inches) in north and northeast China. Approximately 31 percent of the total land area is classified as arid, 22 percent as semiarid, 15 percent as sub-humid, and 32 percent as humid. [Source: Worldmark Encyclopedia of Nations, Thomson Gale, 2007]

The country's north is prone to droughts, while the south is often flooded. Much of the country's farming still relies on rainfall as many of its communities have a poor irrigation system. Seasonal monsoon winds do not influence China as much as India and South Asian countries but they do have a strong impact. The early summer is the peak rainy season in much of China. Seasonal rain fall is often unpredictable, resulting in droughts and floods. Cyclonic storms sometimes approach from Europe. Typhoons strike from time to time, particularly along the southeast coast, in late summer and early fall.

Regional Climate Variation in China

The complex climatic patterns range from the cold-temperate north to the tropical south, with subarctic-like temperatures in the Himalaya Mountains, resulting in a temperature difference of some 40 degrees C from north to south. Temperatures range from –30 degrees C in the north in January to 28 degrees C in the south in July. The prevailing winds blow across southern China from the southeast. Further north they blow in from the west. Cold air pours down from Siberia in the winter. Warm air comes up from Southeast Asia and the South China Sea in the summer.

China's northernmost point lies along the Amur River (Heilong Jiang) in Heilongjiang Province, which borders Siberia and the Russian Far East, in the cold-temperate zone; its southernmost point, Hainan Island, has a tropical climate Temperature differences in winter are great, but in summer the diversity is considerably less. For example, the northern portions of Heilongjiang Province experience an average January mean temperature of below 0°C, and the reading may drop to minus 30°C; the average July mean in the same area may exceed 20°C. By contrast, the central and southern parts of Guangdong Province experience an average January temperature of above 10°C, while the July mean is about 28°C. [Source: Library of Congress]

Minimum winter temperatures range from -27°C (-17°F) in northern Manchuria to -1°C (30°F) in the North China Plain and southern Manchuria, 4°C (39°F) along the middle and lower valleys of the Yangtze, and 16°C (61°F) farther south. Although summer temperatures are more nearly uniform in southern and central China, with a July mean of about 27°C (81°F), northern China has a shorter hot period and the nights are much cooler. [Source: Worldmark Encyclopedia of Nations, Thomson Gale, 2007]

At the highest elevations in southwestern China, there are only fifty frost-free days per year. The hottest spot in China is in northwestern China in the Turpan Depression, where summer highs can reach 47°C (116°F). In some places in northern China summer temperatures only reach 12°C (54°F). In the Yangtze River valley, the mean temperature in summer is 29°C (85°F). [Source: Junior Worldmark Encyclopedia of Physical Geography, Gale Group, Inc., 2003]

Precipitation map

Seasonal Climate Variation in China

During summer, warm, moist, maritime airmasses bring heavy rains to eastern China, and hot, humid, summer weather is typical. Winter offers a sharp contrast when cold, dry Siberian air-masses dominate and often penetrate to the southern provinces. Little precipitation falls during the colder months; low humidity and low temperatures are the norm. Clear days also used to be the norm but smog and coal smoke often blot out the blue skies. During late winter and early spring, strong north winds sweep across northern China, and hazy days, caused by dust storms, are common. [Source: Cities of the World, Gale Group Inc., 2002, adapted from a December 1996 U.S. State Department report]

The capital, Beijing, in northeast China, has cold winters and warm summers, with moderate rainfall. Shanghai, in central China has milder winters and more rain. For China as a whole, the average temperature in January is 15.2°C (59.4°F) and the average temperature in July: 28.4°C (83.1°F). [Source: Junior Worldmark Encyclopedia of the Nations, Thomson Gale, 2007]

Climate in Southern China

Southern China is a semitropical region with lots of rain, a mild winter (December, January, February), and a hot and humid summer that extends from May to September. The best times to visit are in the fall (October, November) and to a lesser extent in the spring (March, April). The spring is often hazy and rainy, whereas the fall often features clear blue skies with puffy clouds.

The temperatures are generally cooler in the highlands and along the coast. In the summer, the humidity is high, often 90 percent or more, and high temperatures are usually around 90̊F. The temperatures can sometimes drop into the 40s at night in the winter, spring and autumn. Snow falls on the higher mountains.

Southern China is affected most by the monsoon season, which is known to Chinese as the "plum rain season" and is dominated by the Bai-u front. In most places the monsoon season extends from June to September . In some places it begin in May. The Bai-u front brings seasonally heavy rains in June and July. The typhoon season is from July to October. The typhoons that strike southern China come in from the Pacific and South China Sea and are usually characterized more by their heavy rains than high winds.

Climate in Central and Northern China

Central and Northern China have four seasons, and the climate is comparable to that of the eastern United States, with the lengths and intensity of the winters and summers varying with the latitude and proximity to the sea. Spring is pleasant, sunny and mild. Summer, arriving in June and often accompanied by month-long rainy season, is characterized by hot, humid weather. The winters tend to be cold and dry. There is snow in many places.

The fall is the nicest time of the year in northern China. The days are often clear; the air is brisk and bracing; the temperatures are cool and there are pretty autumn colors. The spring — especially in Inner Mongolia, Gansu and Shanxi and areas upwind from Beijing — is often very windy, with some intense dust storms that fill the air with chocking grit and turn the sky orange.

Climate in Northwest China and Tibet

Northwest China is very dry, with many places receiving less than four inches of rain a year. Many of the towns and cities have grown up around oases. The summers tend to be scorching and dry with chilly nights and daytime high temperatures that often exceed 110̊F. In some ways the summers are more bearable in the northwest China than elsewhere in China because the humidity is low and the early mornings are relatively cool. The winters are bitterly cold with temperatures often dropping below 0̊F. Spring and autumn are relatively short but pleasant except when fierce dust storms blow up in the spring.

Tibet has a harsh climate. The temperatures frequently drop below minus 30̊F in the winter and rise above 100̊F in the summer, with temperature sometimes fluctuating 80 ̊F in a single day. But generally Tibet is cool or cold and people walk around bundled up in many layers of clothes. It is no surprise that many Tibetans believe that hell is a bitterly cold place not an inferno.

There is very little water in Tibet. Snow frequently falls but rarely accumulates, and the climate is so dry that grain can be stored for 50 years. The extremes of hot and cold, coupled with the thin air and high altitude sunshine, are enough to break granite mountains into sand, and generate fierce winds, stinging hailstorms, and blinding dust storms.

19th Century View of the Weather in China

Arthur Henderson Smith wrote in “Chinese Characteristics”, published in 1894: “The geographical situation and extent of the eighteen provinces of China bear a marked resemblance to that part of the United States of America east of the Rocky Mountains. Contrast the weather in Boston, New York or Chicago, with that of places in the same latitude in China. It is not that China is not, as the geographies used to affirm of the United States, "subject to extremes of heat and cold," for in the latitude of Peking the thermometer ranges through about one hundred degrees Fahrenheit, which ought to afford sufficient variety of temperature to any mortal. But in China these alternations of heat and cold do not follow one another with that reckless and incalculable lawlessness witnessed in the” U.S., “but with an even and unruffled sequence suited to an ancient and a patriarchal system, [Source:“Chinese Characteristics” by Arthur Henderson Smith,1894]

“The Imperial almanac is the authorized exponent of the threefold harmony subsisting in China between heaven, earth and man. Whether the Imperial almanac is equally trustworthy in all parts of the Emperor's broad domain, we do not know, but in those regions with which we happen to be familiar, the almanac is itself a signal-service. At the point marked for the establishment of spring, spring appears. In several different years we have remarked that the day on which the "establishment of autumn" fell was distinguished by a marked change in the weather, after which the blistering heats of "summer," returned no more. Instead of allowing the frost to make irregular and devastating irruptions in every month of the year — as is too often the case in lands where " democracy " rules — the Chinese calendar fixes one of its fourand-twenty "terms" as "frost-fall." A few years ago, this "term" fell on the 23rd of October. Up to that day no lightest frost had fallen. On the morning of that day the ground was covered with white frost, and continued to be so covered every morning thereafter. We have noted these correspondences for some years, and have seldom observed a variation of more than the usual three days of grace, with the exception of the year 1888 in the northern part of Honan, where frost fell eleven days in advance of schedule time. But further enquiry showed that this was a purely local irregularity, undoubtedly due to the depraving influence of the great breach in the Yellow River only a few miles distant. With the resumption of Imperial control over this errant stream, these breaches of climatic uniformity may be expected to disappear.

“It is not inanimate nature only which in China is amenable to reason and to law, but animated nature as well. For some years we have noticed that on a particular day in early spring the window frames were adorned with several flies, where for many months no flies had been seen, and on each occasion we have turned to the Imperial almanac with a confidence justified by the event, and ascertained that this particular day was the one assigned for the " stirring of insects "!

19th Century Chinese Way of Dealing with Rain

Arthur Henderson Smith wrote in “Chinese Characteristics” (1894): ““One of the most common characters in the Chinese language, used to denote imperative necessity, is composed of two parts which signify, "stopped by the rain." With the possible exception of official service, the idea that any human being has functions the discharge of which can be harmonized with the rapid precipitation of moisture in the outer atmosphere, is one that can only be introduced to most Chinese skulls, by a process of trepanning. [Source:“Chinese Characteristics” by Arthur Henderson Smith, 1894]

“Not even public business is necessarily urgent, the proverb to the contrary notwithstanding. We have heard of a Chinese fort, of undoubted strength, in a most important position, armed with the most elaborate monuments of war such as Krupp guns, and provided with foreign drilled troops, where on occasion of a rain, everyone of the sentries judiciously retired to the guard-houses, leaving not a single man anywhere in sight. They were “stopped by the rain!" The Tianjin massacre of 1870 might have been quadrupled in atrocity, but for a timely rain, which deterred the desperadoes already on their way to the Settlement.

A portable shower would be one of the most perfect defences which a foreign traveller in the hostile parts of China could desire. We are confident that a steady stream of cold water delivered from a two inch nozzle, within five minutes of solar time, would disperse the most violent mob ever seen by a foreigner in China. Grape shot would be far less effectual, for many would stop to gather up the spent shot, while cold water is something for which every Chinese from the Han dynasty downwards, entertains the same aversion as does a cat. Externally or internally administered, he regards it as equally fatal. The Chinese has learned to accommodate himself to his environment. To such inconveniences as he encounters he submits with exemplary patience, because he well knows them to be inevitable.

Weather Preparations for the 2008 Olympics in Beijing

The Chinese were obsessed with the weather before and during the 2008 Olympics in Beijing. There was an entire newspaper devoted to the topic. Four satellites were positioned to transmit weather data during the Games. Radar systems were upgraded so that storms and rainfall could be predicted for specific venues. The Beijing Weather-Engineering Office hired 32,000 people and set up 26 controls stations to create a “defensive web” around the Bird’s Nest stadium to prevent rain that might dare to fall on the Opening Ceremonies. Weather forecasters ran hourly forecasting meetings; used advance radar to monitor things like approaching typhoons, weather fronts and evening thunderstorms; and employed a super computer recently bought from IBM for “several million dollars” to help to predict the weather and pollution levels.

The IBM supercomputer was 1,000 times more powerful than any other weather forecasting system used at previous Olympics. With this technology forecasters hoped to make detailed forecasts for specific sites and sports and help athletes by giving them accurate predications of wind speeds and direction and temperatures at specific times of the day. The computer provided every venue with three-hourly forecasts and half-hourly satellite pictures. The information was distributed on text messages, TV screens, scoreboards and the Internet.

Meteorologist from seven countries — China, Japan, the United States, France, Australia, Canada and Austria — competed to see who could predict the weather most accurately. Weather forecasts were made every three hours for up to 36 hours in advance and the champion was determined based on how well the forecasts matched up with the real weather.

The weather turned out to be very cooperative, extraordinarily so. Before the Olympics the weather went according to script. June was the wettest June in 15 years and the heavy rains that fell then helped cool temperatures and clean up the air when the full scale anti-pollution measures kicked in at the end of July. Smog accumulated though despite the measures but it was washed away thank to winds and rains associated with Typhoon Fung-Wong which made landfall south of Beijing.

Milwaukee Reporter Finds 2022 Beijing Winter Olympics Excruciatingly Cold

Reporting from Zhangjiakou, the site of several 2022 Beijing Olympics events, and located about 200 kilometers northwest of Beijing, Lori Nickel wrote in in the Milwaukee Journal Sentinel: “Born and raised on Milwaukee’s south side, I have endured 40 Wisconsin winters (and more in Chicago and Indiana) and you know what that means. Polar vortexes that make it so cold we cancel school. Blizzards that turn our store parking lots into seasonal mountain ranges. I ski and hike in the cold. We live where the air hurts our face. I did not fear China’s cold.Until Thursday night. [Source: Lori Nickel, Milwaukee Journal Sentinel, February 4, 2022]

“My first actual event assignment at the Beijing Winter Games was to monitor the men’s moguls qualifiers. That means I didn’t have to write anything unless something disastrous happened, and I probably could have even kept an eye on it in the media press building about a block away, on TV. It was a kind first assignment for this rookie Olympics reporter.

“Anyway, I wore my B game: a long-sleeved shirt, a turtleneck, a cotton hoodie and a long down coat; pants underneath another pair of fleece-lined pants; cotton socks and wool socks; Columbia boots; Nike running gloves underneath wool knit mittens made in Finland with two Hot Hands warmers stuffed in each; the required N95 mask; a knit hat under a hood.

“Ninety some minutes later, and China’s Jack Frost was kicking my butt....It was 10 degrees and quickly dropping, but the wind, y’all. Up on that mountain, it hits you from any side it wants. I did jumping jacks, shuffles. We all did. Thank goodness the DJ played fun music to bounce to. But then I pulled out my tape recorder. I saw it was acting weird. It was freezing up. My burner phone was too. I stuffed them in my mittens trying to keep them warm. Raced through a few interviews trying to smile through my frost-covered eyelashes and eyebrows. I’ve got a few more things I can try to stay warm. I hope it works.

Image Sources: Dartmouth College; All Posters com, NASA; UNCCD; Xinhua; AFP; BBC; The Hindu; Gary Braasch

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, National Geographic, The New Yorker, Time, Newsweek, Reuters, AP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.

Last updated June 2022