Why is the temperature in Kunming so constant all year round?

Kunming is the capital of Yunnan Province with a history of more than 2,400 years. It is the center of politics, economy, culture, science and technology and transportation in Yunnan Province, and it is also a famous historical and cultural city and an excellent tourist city in China.

Kunming is located in the middle of Yunnan-Guizhou Plateau, with an altitude of 1, 89 1 m in the city center. Dianchi Lake is in the south, surrounded by mountains on three sides. It belongs to the monsoon climate of low latitude plateau and mountainous area. Affected by the warm and humid airflow in the southwest of the Indian Ocean, the sunshine is long, the frost period is short, and the annual average temperature is 15. C. The climate is mild, with no heat in summer, no severe cold in winter, spring-like seasons and pleasant climate. It is a prestigious "Spring City". From February of 65438 to March of the following year, flocks of red-billed gulls, fleeing from the cold wind in the northern waters, fly from Wan Li and settle in Kunming.

Climatic characteristics of Kunming:

Climatic conditions:

Kunming is located in the low latitude plateau, with complex and diverse landforms, great topographic differences and obvious vertical and horizontal climate differences. In the mountainous area, there are scenes of "flowers bloom under the mountain and snow falls on the mountain" and "Yongshan is divided into four seasons, and ten miles are different from the sky". According to the statistics of meteorological data since the founding of the People's Republic of China, the annual average temperature in Kunming is 14.5℃, the average temperature in the hottest month (July) is 19.7℃, and the average temperature in Leng Yue (65438+1October) is 7.5℃, and the annual temperature difference is12 ~/kloc. The annual precipitation is about 103l mm, and the relative humidity is 74%, with little humidity. In recent years, the frost-free period has been more than 240 days. There are many sunny days throughout the year, with annual sunshine hours of 2445.6 hours and sunshine rate of 56%. The annual projection angle of the sun is large, and the annual average total radiation is 129.78 kcal/cm2, of which 62.78 kcal/cm2 in rainy season and 67 kcal/cm2 in dry season, with little change in two seasons. Therefore, the poet Yang Shengan praised Kunming for "the weather is often like February and March, and flowers are always in spring".

Climatic characteristics:

Kunming is located in the subtropical north latitude. However, most areas in China have typical temperate climate characteristics and are known as "Spring City" at home and abroad. The main features of the climate in Kunming are as follows.

1. Spring is warm and dry, with little rain, strong wind and strong evaporation, and the daily temperature changes greatly.

In spring, the airflow comes from the tropical continent. The weather is fine, and the average monthly temperature is below 20℃. But the temperature difference between day and night is large, which has the characteristics of "spring in the morning, summer in the afternoon, autumn in the evening and winter in the middle of the night". There is little precipitation in spring, low air humidity, large evaporation and rapid temperature rise, which makes agricultural production vulnerable to drought, which is not conducive to the growth and sowing of crops in spring.

There is no high temperature in summer, and the rainfall is concentrated.

In summer, the airflow comes from the tropical ocean, rainy weather, abundant water, moist soil, less solar radiation absorbed by the ground, and more radiant heat is used for water evaporation. Therefore, in midsummer, except for areas below 1600 meters above sea level, the average temperature can reach the summer standard of 22℃ in about two months, and most other areas belong to the spring climate below 2 1℃, so there is no hot summer period. Summer rainfall is concentrated, with heavy rain and heavy rain, and precipitation accounting for more than 60% of the whole year, which is prone to floods.

3. Autumn is crisp, the weather is crisp, the rain is reduced, and the first frost period begins.

In autumn, the temperature drops rapidly and the weather is dry. In most areas, the temperature is about 2℃ lower than that in spring. Precipitation is reduced by more than half compared with summer, but it is more than winter and spring, and autumn drought is rare. Generally, the rainy season ends in the first half of June 65438+1October, and the first frost period begins in the first half of June165438+1October.

There is no severe cold in winter, with plenty of sunshine, sunny weather and little rain.

In winter, the average monthly sunny day is about 20 days, sunshine is about 230 hours, and rainy day is about 4 days. The annual precipitation only accounts for 3% ~ 5% of the whole year. Except for the valley area below 65,438+0,5500m m, the winter lasts for more than two months in most areas of the city (the five-day average temperature is lower than 65,438+00℃), and sometimes there will be cold weather, frost or snowfall, which may cause crops to suffer in early spring.

5. There is a clear distinction between dry season and rainy season

The annual precipitation is obviously divided into dry season and wet season in time distribution. May ~ 10 is the rainy season, and the precipitation accounts for about 85% of the whole year. The dry season is 1 1 to April of the following year, and the precipitation only accounts for about 15% of the whole year. In April and May, the precipitation 10 and 1 1 changed greatly. The precipitation in May is two or three times more than that in April, and 1 1 monthly precipitation is more than that in June 1 times.