Weather conditions throughout the year in Beijing, Lhasa, Shenzhen, Kunming and Harbin

Beijing’s four-season weather conditions

Beijing belongs to the warm temperate semi-humid monsoon continental climate zone in the national climate division. However, the landform within the territory is complex, and the relative height difference between the mountain peaks and the plains is very different, resulting in obvious vertical climate zonation. It is roughly bounded by an altitude of 700-800 meters. Below this boundary to the plains, it is a warm temperate zone semi-humid monsoon climate; above this boundary, the middle and mountainous areas have a temperate zone semi-humid-semi-arid monsoon climate; above about 1,600 meters above sea level, it is a cold temperate zone semi-humid-humid climate. Monsoon climate.

Climate Characteristics

The main characteristic of Beijing’s climate is the four distinct seasons. The spring is dry, the summer is hot and rainy, the autumn is high and the air is cool, and the winter is cold and dry; the wind direction has obvious seasonal changes, with northwest wind prevailing in winter and southeast wind prevailing in summer. The climate characteristics of the four seasons are as follows:

Spring

The temperature rises quickly, the temperature difference between day and night is large, and it is dry and windy. In spring, as the sun's altitude angle gradually increases, the daytime lengthens, and the heat gained by the ground exceeds the expenditure, so the temperature rises rapidly. The monthly average temperature can rise by 9-6°C, with the average temperature in March being 4.5°C and April being 13.1°C. The temperature is high during the day, while radiation cooling is strong and the temperature is low at night. This is the season with the largest temperature difference between day and night. Generally, the daily temperature range is 12-14℃, with the maximum daily temperature range reaching 16.8℃. In addition, cold air activities are still very frequent in spring. Due to the rapid cooling, "late spring cold" weather appears, which is easy to form late frost. It is not very windy, and the number of windy days above level 8 accounts for 40% of the total number of days in the year. When strong winds occur, they are often accompanied by floating dust, blowing sand, and sandstorms. The sparse precipitation in spring aggravates the spring drought, which is known as "spring drought nine times out of ten years".

Summer

The summer is hot and the precipitation is concentrated, resulting in rain and heat in the same season. In summer, except for mountainous areas, the average monthly temperature in plain areas is above 24°C. Although the hottest month is not June, the extreme highest temperature mostly occurs in June. The extreme highest temperature was 43.5℃ on June 10, 1961. Entering midsummer, July is the hottest month of the year, with an average temperature close to 26°C. The high temperature is long-lasting and stable, and the temperature difference between day and night is small. Summer precipitation accounts for 70% of the annual precipitation, and mostly occurs in the form of heavy rain. The city's largest one-day precipitation reached 479 mm (July 27, 1972). Therefore, mountainous areas are prone to flash floods, plains are prone to floods, and heavy rains are one of the major natural disasters in Beijing in summer. In addition, thermal convection in mountainous areas is strong, causing thundershowers in some areas, accompanied by hail, causing certain losses to agriculture.

Autumn

The sky is high and the air is crisp, the temperature is suitable, and the sunshine is sufficient. After autumn, cold air from the north begins to invade and the temperature drops rapidly. Therefore, the premature arrival of first frost occurs.

Winter

It is cold and long. Winter lasts for 5 months. If the average temperature is below 0℃, it is considered severe winter, and it lasts for 3 months (December-February). In mid-winter, the average temperature in the plain areas is below -4℃, in the mountainous areas it is below -8℃, and the extreme minimum temperature in the plains is -27.4℃. Winter precipitation accounts for 2% of the annual precipitation, and there are often no precipitation (snow) records for more than one month in a row. Although winter is cold and dry, there is plenty of sunshine, with an average of more than 6 hours of sunshine a day, creating favorable conditions for the development and utilization of solar energy.

Lhasa City is located in the southeast of the Tibet Autonomous Region, on the north bank of the Lhasa River, a tributary of the Brahmaputra River. The climate belongs to the plateau temperate semi-arid wind climate zone, with annual rainfall of 200-510 mm, concentrated in June-September, with many nights of rain. The highest temperature is 28℃ and the lowest temperature is minus 14℃. The air is thin, the temperature is low, the daily temperature difference is large, winter and spring are dry and windy, and the annual frost-free period is 100-120 days. Relatively speaking, the climate is warm and humid from March to October, which is the best travel season in Tibet, and the annual May Day holiday is usually the beginning of the travel season.

Shenzhen has a south subtropical monsoon climate, with pleasant wind and abundant precipitation. The annual average temperature is 22.5°C, with the highest extreme temperature being 38.7°C and the lowest -2°C. The frost-free period is 355 days, the average annual rainfall is 1924.3 mm, and the sunshine is 2120.5 hours, making it suitable for year-round tourism.

Kunming belongs to the northern latitude subtropical zone. However, most areas in the territory have neither scorching heat in summer nor severe cold in winter. The climate is pleasant and has typical temperate climate characteristics. The urban temperature ranges from 0 to 29°C, and the annual temperature difference is the smallest in the country. , such climate characteristics are rare in the world. Therefore, Kunming is known as the "Spring City" at home and abroad.

Harbin is located in the middle and high latitudes of the eastern part of the Eurasian continent, between 44°04′ and 46°40′ north latitude and 125°41′ and 130°13′ east longitude. The west and southwest are surrounded by pine trees. Nen Plain, the north and northeast are the Lesser Khingan Mountains, and the east and southeast are the Zhangguangcai Mountains of the Changbai Mountains.

According to my country's climate zones, Harbin's climate belongs to the mid-temperate continental monsoon climate. Affected by the monsoon circulation system in the polar front convergence zone, it has obvious monsoon characteristics. The winter monsoon is stronger than the summer monsoon and comes earlier, while the summer monsoon comes later. The winter monsoon comes from the high latitude inland and is controlled by the polar continental air mass. It is cold and dry, with frequent cold waves and long winters. The summer is affected by the tropical marine air mass and is warm and rainy. When the winter and summer monsoons alternate, the summer monsoon gradually develops from south to north. The summer monsoon reaches its peak from late July to early August, which is the period when rainfall is most concentrated in Harbin. From mid-August to early September, the summer monsoon gradually retreats, ending from north to south.

Monsoon climate produces obvious seasonal winds and the prevailing wind direction changes alternately. Westerly or northerly winds prevail in winter, and southerly or southeasterly winds prevail in summer. Spring and autumn are shorter, with southerly and northerly winds alternating.

Climate Characteristics Harbin's climate is characterized by four distinct seasons, long and cold winter, short and hot summer, and rapid temperature rise and fall in spring and autumn, which are transitional seasons with short duration. Affected by the alternation of geographical environment, sea and land air masses and monsoons, the city's climate varies significantly among seasons and changes greatly. In winter, under the control of polar continental air masses, the climate is cold and dry; in summer, under the influence of subtropical ocean air masses, precipitation is abundant and the climate is warm; in spring and autumn, due to the alternating influence of winter and summer monsoons, the climate is changeable, with strong winds and little precipitation in spring. It is prone to drought; the temperature drops sharply in autumn, and frost damage is common.

Spring climate Spring (March-May) is the transition season between winter and summer, with rapid temperature rise, less precipitation, more winds, dry air, changeable weather, and large temperature fluctuations. Temperature changes strongly from month to month, generally around 8 to 10°C. The city's annual average spring temperature is 5.1°C. The low temperature centers are in Shangzhi, Yanshou and Tonghe, with the average spring temperature over the years being below 4.4℃; the high temperature centers are in Shuangcheng, Acheng and Bin County, with the average spring temperature over the years being above 5.6℃. The city's spring precipitation averages 80.2 mm over the years, with 39.0 mm in wet years (1989) and 127.9 mm in wet years (1976). Spring precipitation is more in the south and east, prone to spring floods; less in the west, prone to spring drought. The wind speed is the highest in spring, with the maximum wind speed between April and May ranging from 22 to 37 meters/second, and the maximum wind speed in the past years is 37 meters/second (Acheng on May 3, 1974); the average number of windy days is 25, and the maximum number of windy days in Yilan is 63 days. The last frost varies greatly among counties in the city, with the average last frost over the years being May 10th; Shuangcheng, Acheng and Binxian on May 5th; Wuchang, Fangzheng and Yilan in early and late May; Bayan, Mulan, Tonghe and Yanshou is in mid-May; only Shangzhi is in late May or early May. The final frost varies greatly from year to year, and can sometimes be about 10 days earlier or later than normal. The delayed final frost will cause late frost, which is also a major disaster for agricultural production.

Summer climate The climate in summer (June-August) is warm and hot, with abundant rainfall and sunlight and hot water in the same season, which is conducive to agricultural production. The city's annual average summer temperature is 20.8°C, varying between 19.4-22.4°C; the lowest value of 19.4°C occurred in 1983, and the highest value of 22.4°C occurred in 1994. Although the change in average summer temperature is very small, with a difference of only 3°C, it has a great impact on agriculture. Summer temperatures are also higher in the west and lower in the east. July is the month with the highest temperature in the whole year. The city's average temperature over the years is 22.3℃; among them, Shangzhi, Yanshou, Tonghe and Yilan are less than 22℃. The monthly difference in temperature is very small, generally only 2-3℃, which is the smallest in each season. The city's annual average summer precipitation is 379 mm; the annual variation ranges from 197.5 to 633.7 mm, with a difference of more than 2 times. The cities with annual average seasonal precipitation greater than 400 mm include Shangzhi, Wuchang and Bayan. The precipitation intensity is not great, with an average of 1 to 2 rainstorm days, and extremely heavy rainstorms are rare. Generally, heavy rains mostly occur in the eastern mountainous and hilly areas, which can easily cause flash floods or waterlogging.

Autumn climate Autumn (September to October) is the transition season from summer to winter. Due to the influence of cold air from the north, the climate changes from warm to cold. Cyclone activity is second only to spring, and the weather is changeable. Whenever a cold front passes, the temperature drops sharply. The temperature range varies from month to month by 8 to 9 degrees Celsius. The city's annual seasonal average temperature is 9.4°C; the inter-annual variation range is between 7.9 and 11.1°C, with little change. The average annual first frost in the city is September 23; the earliest frost occurs on September 7 (Shang Zhi and Yanshou 1976). Since frost is greatly affected by terrain, the date of first frost varies between plains and mountainous areas. After autumn, precipitation decreases significantly, but is more than in spring. The city's average annual precipitation is 94.3 mm; the inter-annual variation ranges from 46.2 to 167.1 mm; the precipitation in Shangzhi, Yanshou, Fangzheng and Tonghe in the eastern mountainous areas is greater than 100 mm. The wind speed is higher in autumn, second only to spring, and the wind direction is mainly southerly.

Winter climate In winter (November to February of the following year), controlled by the dry and cold polar continental air masses, the temperature is very low, precipitation is very little, and the climate is cold and dry. The average temperature in winter is -14.2℃. January is the coldest month, with the city’s annual average temperature being -19.6°C. The city's average annual precipitation (snow) in winter is 23.6 mm; the inter-annual variation ranges from 6.6 to 35.4 mm, a difference of nearly 5 times. In winter, southwesterly wind prevails in the city with very low wind speed. Blizzard weather sometimes occurs.

Climate extremes: The annual average maximum temperature in Harbin is 5.9℃ (Bin County in 1990), and the annual average minimum temperature is 0.7℃ (Yanshou County in 1969). The daily extreme maximum temperature is 37.8℃ (occurred in Yilan County on July 8, 1982), and the daily extreme minimum temperature is -42.6℃ (occurred in Yanshou County on January 4, 1970). The annual extreme maximum precipitation is 1081.3 mm (occurred in Shangzhi City in 1960), and the annual minimum extreme precipitation is 247 mm (occurred in Shuangcheng City in 1989). The annual maximum number of extreme precipitation days reaches 159 days (occurred in Shangzhi City in 1957), and the annual minimum number of extreme precipitation days is only 80 days (occurred in Shuangcheng City in 1962). The maximum daily precipitation is 168.3 mm (occurred in Bayan County on August 1, 1960).

The extreme maximum wind speed was 37.0 meters/second (occurred in Acheng City on May 3, 1974).

(Source: Harbin Meteorological Bureau)