Geographical monsoon climate in Zhuhai

Zhuhai is located in the south of the Tropic of Cancer, with obvious alternating monsoon in winter and summer. The temperature is high all year round, with occasional cold showers, but there is no severe cold in winter and no heat in summer. The annual and daily temperature difference is small, and it belongs to the south subtropical maritime monsoon climate.

Characteristics of the four seasons

There is a big difference between the astronomical season time and the natural climate season time in Zhuhai. In a year, the time of each season is different, even in the same season over the years, the starting time is different. The difference between early season and late season is more than two months.

Spring is a season with changeable weather all the year round. The season is mainly easterly, with changeable wind direction and great temperature change. The highest temperature is 32.5℃ (1April 23, 987) and the lowest temperature is 2.9℃ (1March 60, 986). In most years, the climate gradually warms up in spring, and by mid-April, it is close to the annual average temperature. In some years, there is still strong cold air influence from March to early April, and even the "late spring cold" weather with daily average temperature lower than 12℃ lasts for several days.

In summer, May to June is the first flood season of the rainy season. Zhuhai is located in the northwest of the subtropical ridge in the western Pacific Ocean, and is often affected by the trough of low pressure at high altitude. There are many strong convective weather such as thunderstorms and showers, and the rainfall increases. 1962- 1990, the maximum rainstorm occurred on June 1966, with a daily rainfall of 393.7mm ... in midsummer, from July to1mid-October, which is the typhoon prevailing period. Affected by the tropical weather system, tropical cyclones (tropical depression and typhoon) formed in the South China Sea and the western Pacific Ocean sometimes attack and affect Zhuhai, often caused by typhoons and heavy rains. July-September is a hot period in a year, and the upper air is often controlled by subtropical high. The weather is sunny, the temperature is high, the sunshine is abundant, and the evaporation is large. The average temperature in July is 28.6℃ and the highest temperature is 38,5℃ (1July 980 10).

In autumn, the dry winter wind gradually replaces the warm and humid summer monsoon (southeast wind), and the autumn is crisp. In early autumn, it will also be affected by tropical depression and typhoon in the South China Sea and the western Pacific Ocean, which will bring heavy rain. After the end of June 5438+ 10, the impact of the typhoon has come to an end, and the rainy season in the later flood season has ended. 165438+1After early October, cold air activities began to increase, the temperature gradually decreased, and the dry season began.

Winter lasts about one month, and the northeast monsoon prevails. Cold air goes south once every seven days on average. Between the two cold air streams, the weather was unusually warm at first, and then a strong cold air came and became cold again. At the same time, the sea surface is often accompanied by strong winds of magnitude 6 or above. The coldest month is 65438+ 10, with the monthly average temperature of 14.5℃ and the extreme minimum temperature of 2.5℃ (19765438+February 29th). Winter is mostly sunny, especially the previous winter, when the rainfall is scarce. In some years, it never rains in February and October During the transition period from winter to spring (February), cold and warm air is frequently exchanged, and there is often low-temperature weather with continuous low temperature and rainy days.

rain

Zhuhai is abundant in rainfall, with the annual average rainfall of1962-19901985.8mm, the maximum rainfall of 1973 2873.9mm, and the minimum rainfall of 1963 of1200.9mm. There are two obvious rainy seasons throughout the year: April-June is the rainy season in the first flood season, and the rainfall is mainly due to the low trough of the front, low-level jet, vortex or high-altitude shear line.

Due to the influence of weather system, the average total rainfall is 840 mm, accounting for 42% of the annual rainfall; From July to June, 5438+ 10 is the rainy season in the late flood season, and the rainfall is mainly caused by tropical weather systems such as tropical cyclones, with an average total rainfall of 946 mm, accounting for 47% of the annual rainfall. Due to the intensity of typhoon rainstorm and heavy rainfall in the late flood season, a rainfall process can reach 200-300 mm, which is easy to cause local floods.

wind

Due to the influence of different weather systems and topography, the wind direction in Zhuhai has the basic characteristics of changing with the monsoon. There are many southeast winds and easterly winds in spring; In summer, the south wind and southwest wind are dominant; Autumn is dominated by northeast wind and northeast wind; The north wind and northeast wind are the most in winter. Southeast wind and northeast wind prevail all year round.