The weather in Beijing will change within a year.

Spring: the temperature rises quickly, the temperature difference between day and night is large, and it is dry and windy. In spring, with the gradual increase of the sun's altitude angle, the daylight time is prolonged, and the heat obtained on the ground exceeds the expenditure, so the temperature rises rapidly. The monthly average temperature can be increased by 9-6℃, the average temperature is 4.5℃ in March and 13. 1℃ in April. The daytime temperature is high, the nighttime radiation cooling is strong, and the temperature is low, which is the season with the largest temperature difference between day and night. The average daily temperature difference is 12- 14℃, and the maximum daily temperature difference is 16.8℃. In addition, the cold air activity is still very frequent in spring, and due to the severe cooling, there is "late spring cold" weather, which is easy to form late frost. There are many windy days, and the windy days of magnitude 8 or above account for 40% of the total days of the year. When strong winds appear, they are often accompanied by floating dust, sand blowing and sandstorm weather. The scarcity of precipitation in spring aggravated the spring drought, which is called "ten years and nine spring droughts".

Summer: Summer is hot and hot, and precipitation is concentrated, forming the same season of rain and heat. In summer, except in mountainous areas, the average monthly temperature in plain areas is above 24℃. Although the hottest month is not June, the extreme maximum temperature mostly occurs in June, and the extreme maximum temperature in June 196 1 day is 43.5℃. July is the hottest month in a year, with an average temperature close to 26℃, a continuous and stable high temperature and a small temperature difference between day and night. Summer precipitation accounts for 70% of the annual precipitation, mostly in the form of heavy rain. The maximum daily precipitation in this city reaches 479 mm (1July 27, 972). So it is prone to flash floods, and the plains cause floods. Rainstorm is one of the main natural disasters in Beijing in summer. In addition, the strong thermal convection in mountainous areas has caused local thunderstorms accompanied by hail, which has caused certain losses to agriculture.

Autumn: the weather is crisp, the temperature is suitable and the light is sufficient. After autumn, the cold air in the north began to invade and the temperature dropped rapidly. Therefore, the early arrival of the first frost often happens.

Winter: the cold is long. Winter lasts for five months, and if the average temperature is below 0℃, it lasts for three months (1February-February). In the winter of 65438+ 10, the average temperature in the plain is below -4℃, in the mountainous area it is below -8℃, and the extreme minimum temperature in the plain is -27.4℃. Winter precipitation accounts for 2% of the annual precipitation, and there is often no record of precipitation (snow) for more than one month. Although it is cold and dry in winter, there is plenty of sunshine, averaging more than 6 hours a day, which creates favorable conditions for the development and utilization of solar energy.