The sub-tropical monsoon climate, clearly defined seasons and sufficient rainfall provide good conditions for vegetation to grow. Summer and winter are longer while spring and autumn are shorter. Here, summer lasts approximately 124 days, winter 110 days, spring 70 days and autumn 61 days. January is usually the coldest time with an average temperature of 4.4-5.1 degrees Centigrade. The annual precipitation on average is 1,358.6mm-1,552.5mm. Changsha has a number of parks occupying a total area of 575 hectares, which include the Martyrs' Park, Juzhou Park, Tianxin Park, Yuelushang Scenic Area, the Changsha Zoo and several forests and botanic gardens.
The people's government of Changsha has adopted a sense of measures to improve the local environment and ecology. Environmental protection departments have been established at each level of the government, with a total staff of 333. environmental inspections have become regular, which include monitoring the water quality in the Xiangjiang River and urban wells as well as the air quality in the city areas. In this way these departments have the environmental quality of the city under constant supervision, which provides a scientific basis for preventing and dealing with pollution. It is a requirement that every industrial construction project is built in conjunction with a sewage disposal project, which is a part of its design plan. Up to now Changsha has two sewage disposal plants, with a daily capacity of sewage totaling 250,000 tons.