Huanggang belongs to subtropical continental monsoon climate and Jianghuai microclimate zone. The boundary between light and heat in the four seasons is clear. The annual solar radiation is106.49-113.31kcal/cm2, and the average sunshine hours are1913.5-216/kloc. The sunshine in the northwest is higher than that in the southeast. The annual average temperature is15.7℃-17.1℃. The frost-free period is between 237 days and 278 days. The annual average rainfall is1223-1493mm, the annual total rainfall is 22.237 billion cubic meters, and the number of rainy days (≥0. 1 mm days) is between 1 15- 147 days. Adequate sunshine and rain are favorable conditions for plant growth. However, the climatic factors are unevenly distributed, and there are often floods, droughts, low temperature freezing and high temperature. In 2005, the average temperature in the city was high, and it was cold in winter. Most counties and cities have less precipitation all the year round, and there is a phenomenon of "less plum" during the "plum rain". There are many meteorological disasters in the whole year, such as "late spring cold", low temperature and rainy weather, local rainstorm and drought. The flood Dabie mountain range is a natural barrier, which not only blocks and weakens the invasion of cold air from the south, but also lifts the warm and humid airflow from the south, making Luotian and Yingshan one of the rainstorm areas in the Yangtze River basin. If the heavy precipitation in the middle and upper reaches of the Yangtze River occurs at the same time as the heavy precipitation in this city, it will form a river jacking, and the internal waterlogging will not flow out, which will greatly aggravate the flood disaster. According to the records of the meteorological department since 1959, there have been floods in the whole city for 10 years, of which 7 years (1964, 1969, 1983,19/kloc) Floods mainly occur in summer, and there are 10 floods above the average in the city, that is, there are 8 floods during the Meiyu period (from late June to late July). The north-central part is heavier than the south. Drought There are four kinds of droughts in the city: winter drought, spring drought, summer drought and autumn drought, among which summer drought and autumn drought are the most important. Since 1959, there have been more than moderate summer droughts in the city *** 13 times, with an average of once every 2-3 years. 9 droughts (1959, 19 1, 1964, 1966, 1967, 1972,/kloc-0). There are many droughts in Huanggang and Macheng in summer, with an average of once every four years. Yingshan and Luotian are relatively rare, averaging 10 years. Autumn drought in Yingshan and Luotian is still less, only 1 time, and 2-4 times in other places. The droughts in summer and autumn mainly occurred before 1980s, with *** 18 times. After 1980s, there were only three moderate summer droughts.