Geographical climate of Hong Kong

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14 52

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14 7 1

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17 189

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2 1 330

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24 388

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26 374

3 1

27 445

3 1

26 288

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26 152

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23 35

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19 35

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16 The temperature is expressed in degrees Celsius (C) and the unit of rainfall is expressed in millimeters (mm). Source: Hong Kong Observatory English unit conversion display ▼ Main items: Hong Kong climate.

The geographical location of Hong Kong leads to a maritime subtropical monsoon climate. Controlled by the monsoon, the four seasons are distinct, but the climate is generally mild. In winter in the northern hemisphere, the cold air gathered in the northern Asian continent makes the air pressure rise, forming a dry winter monsoon blowing to the ocean. Hong Kong is located on the southern coast of the mainland, so the wind is northerly. The monsoon blows across the mainland, so the rainfall is also low. As for summer, it is winter in the southern hemisphere, and the rising local air pressure will make air blow across the Pacific Ocean. Therefore, the summer monsoon in Hong Kong is generally southerly, bringing a lot of rain.

As far as the four seasons are concerned, spring is roughly from March to April. Humidity, fog and light rain are common weather phenomena. May to August is summer, and the high temperature is caused by the high angle of the sun. As mentioned earlier, the Pacific monsoon in the southeast will bring abundant rainfall and tropical cyclone activities. When the tropical cyclone center moves closer to Hong Kong, the winds in Hong Kong will increase, and there may be heavy rain lasting for several days in a large area, resulting in landslides and flooding. Autumn is from September to 10, and it is sunny and crisp most of the time, which is a season suitable for outing. From June in winter 1 1 to February of the following year, the cold source in Eurasia leads to high air pressure, and occasionally a cold front passes by, blowing dry northerly winds.

The rainfall in various parts of Hong Kong is often consistent with the topographic distribution, which is called topographic rainfall. Although there is seasonal wind direction in Hong Kong due to the influence of monsoon, easterly wind is still the main wind direction. The mountains in Hong Kong are arranged in the northeast-southwest direction, and the mountains intersect with the prevailing wind direction at right angles, especially in the east. So overall, the terrain and rainfall will be directly proportional; There will be more rainfall in the east than in the west. In this case, the west is called the rain shadow area of Hong Kong.

In addition, the high-density population and buildings in the urban area of Hong Kong also have an impact on the urban climate. The land covered with concrete has lost its natural heat dissipation function, and the dense high-rise buildings in urban areas also make it difficult for streets to dissipate heat, leading to the phenomenon of heat island in urban areas of Hong Kong. Take 65438+20061October 30th as an example. It was the Double Ninth Festival on the ninth day of the ninth lunar month, which was supposed to be a crisp autumn day. However, the highest temperature reached 29.4℃ that day, and the monthly average temperature of 10 was also 26.4℃. According to the Observatory, this is related to the heat island phenomenon. The weak East Asian monsoon in autumn 2006 may make 20061October 65438+ the hottest month in Hong Kong's history. A study by the Department of Geography of Hong Kong University shows that greening the roofs of buildings helps to reduce the temperature of cities. The difference between a roof covered with plants and concrete is as high as 26℃. HKU scholars criticized the government for not being active enough in roof greening.

Intensive urban construction will block the sun and reduce air flow, and pollutants such as automobile exhaust will easily accumulate, which will aggravate air pollution. In addition to commercial buildings in urban areas, residential buildings facing the sea may also be the "culprit" of the heat island phenomenon. For example, the property development projects above Yuen Long Station, Tai Wai Station, Tai Wai Garage and Nanchang Station in New Territories have also been criticized by environmental protection organizations as being too high and dense, reducing air circulation, hindering heat dissipation and forming a "screen effect".