Is Xi Anbi Yinchuan dry?

Xi belongs to warm temperate semi-humid continental monsoon climate. Four distinct seasons, hot and rainy in summer, cold and little rain and snow in winter, and even rainy weather in spring and autumn. The average annual temperature in Xi 'an and its suburbs is13.1~13.4℃. The annual extreme maximum temperature is 35 ~ 465438 0.8℃; Very low-16 ~-20℃. July is the hottest month in the whole year, with the monthly average temperature of 26. 1 ~ 26.3℃ and the monthly average maximum temperature of about 32℃. 65438+ 10 is the coldest month, with the monthly average temperature of -0.3 ~- 1.3℃ and the monthly average minimum temperature of -4℃ or so, with an annual variation of 26 ~ 27℃. Precipitation changes greatly during the year, and there is a great difference between rainy years and less rainy years, which can reach 590 mm at most. The seasonal distribution of precipitation is also extremely uneven. 78% of the rainfall is concentrated in May ~ 10, of which July ~ September accounts for 47% of the annual rainfall, and there are occasional heavy rains. The annual average relative humidity is about 70%. The annual average wind speed is1.8m/s, and the dominant wind direction throughout the year is northeast wind.

Spring (March-May): The temperature rises rapidly, but the temperature rise is unstable, and the weather of "suddenly warm and cold" often appears. The average temperature in Xi is 7.9℃ in March, 14. 1℃ in April and 19.4℃ in May. Spring rainfall accounts for about a quarter of the annual rainfall, and the average rainfall days in each month are 7-9 days. In spring, the temperature is pleasant and the weather is sunny, which is a good time for outdoor activities and travel.

Summer (June-August): It is characterized by hot and rainy weather. Xi is one of the four largest cities in China. July is the hottest month in the whole year, with an average temperature of 26.3℃. The average temperatures in June and August reached 24.8℃ and 15.3℃ respectively. The annual maximum daily temperature is equal to or greater than 35℃, the average hot period is about 22 days, and the maximum is 1997, reaching 6 1 day. In the 38 years from 196 1 to 1998, extreme high temperature weather above 40℃ occurred in 9 years. Summer rainfall accounts for 37% of the annual rainfall. The average rainy days in each month are 8 ~ 1 1 day, and half of the rainstorm days in the whole year appear in summer.

Autumn (September ~165438+1October): In September, due to the influence of the Pacific subtropical high, Xi 'an has more precipitation and often rainy days. The monthly average rainfall is 99.5 mm, accounting for 19% of the annual rainfall, and the average rainy days for many years are 12 days. Autumn is suitable for cold and warm, and the cooling speed is fast. The monthly average temperatures are 65438 09.6℃, 65438 03.8℃ and 6.8℃ respectively. The average wind speed 1.5m/s is the season with the smallest wind speed in the whole year.

Winter (65438+February ~ February): It is cold and rainy in winter, and the average temperature drops to -0.5℃ in 65438+1October. Due to the strong cold wave in winter, the extreme minimum temperature can be reduced to below-10℃. Rainfall is scarce and the climate is dry. The precipitation in three months is only 24 mm, accounting for only 4% of the annual precipitation.

Climatic characteristics of Yinchuan

Yinchuan is a typical mid-temperate continental climate. The main climatic characteristics are: four distinct seasons, short summer in late spring, long winter in early autumn, large temperature difference between day and night, scarce rain and snow, strong evaporation, dry climate, heavy sandstorm and so on. The annual average temperature is about 8.5℃, and the annual average sunshine hours are 2800 ~ 3000 hours, which is one of the regions with the most solar radiation and sunshine hours in China. The annual average precipitation is about 200mm, and the frost-free period is about 185 days.

Temperature In 2007, the average annual temperature in Yinchuan was 9.6℃ ~ 1 1.5℃, which was 0.6℃ ~ 2.4℃ higher than the same period of last year. Except in June, July and September, Helan county 10 and July, and lingwu city 10, the temperature in other months is higher, especially in February, which is 4.0℃ ~ 5.7℃, and in other months, it is 0.0℃ ~ 2.9℃. Among them, the annual average temperature in Yinchuan is 0. 1 ~ 65438+2℃ ~ 4.8℃, and that in Yongning County is 1.2℃ ~ 5.7℃. In June, July, September and 65438+1October, the temperature in Helan County was 0.4℃, 0.6℃, 0.6℃ and 0.9℃ respectively. Lingwu County was 0.4℃ and 0.8℃ lower in July and 65438+1October, respectively.

Precipitation In 2007, the annual precipitation in Yinchuan was 209.8 mm ~ 222.5 mm, 28.2 mm ~ 33.0 mm more than in previous years. The monthly and regional distribution of precipitation in Yinchuan is uneven. Among them, the annual cumulative precipitation in Yinchuan is 2 14.7mm, the precipitation in March and June is 13.0mm and 102.6mm respectively, and the precipitation in other months is 0.5mm ~ 45.0mm less. Especially in July and August, the rainfall was 465, 438+0.0mm and less than 45.0mm, respectively, resulting in extremely uneven precipitation in the main flood season. The annual accumulated precipitation in Yongning County is 209.8 mm, of which 65438+ 10, March, May, June and September are 0.5mm ~ 73.4mm； more. February, April, July, August, 65438+1October,165438+1October and 65438+February are 0.7 mm to 39.8 mm less. The annual cumulative precipitation in Helan County is 212.0mm; In which February, March, May, June and September are greater than1.1mm ~ 94.0mm; 65438+ 10 month, April, July, August, 65438+ 10 month, 165438+ 10 month, 65438+2 month is 0.5 mm ~ 4/kloc-0. The annual accumulated precipitation in lingwu city is 222.5 mm, including March, May, June, 65438+1October and 65438+February 1.0 mm ~ 77.8 mm. 65438+ 10 month, February, April, July, August, September and 165438+ 10 month is 0.4 mm to 39.3 mm less.

The annual sunshine hours in Yinchuan City of Rizhao ranged from 2 520.6 hours to 3 065 438+065 438+0. 1 hour, which was 17 1.9 hours to 380.0 hours less than that in previous years. Among them, the cumulative sunshine hours in Yinchuan are 2520.6 hours, which is 7.6 hours to 74. 1 hour less than that in July. Especially in June, August, 10 and1February, few photos are obvious. The total sunshine hours in Yongning County are 2 753.3 hours, of which the sunshine hours in April, May, July and1October are 5. 1 ~ 26.6 hours more. Other months are 5.7 hours to 69.1hour less. The cumulative sunshine hours in Helan County are 2 735.5 hours; Among them, April, May and July are 7.6 hours, 25.2 hours and 26.7 hours respectively; Other months are 13.4 hours ~ 66.8 hours less. The total sunshine hours in lingwu city are 2805.3 hours, among which the sunshine hours in June, April, May and June are 6.4-28.4 hours. February, March and June ~ 10 and 12 are 0. 1 ~ 73.6 hours less.