The climate in Changsha has sub-tropical characteristics and is there fore very humid all year round. The city has clearly defined seasons, with an average temperature of 16.8-17.2 degrees Centigrade, reaching 40 degrees in summer and dropping to 1 or 2 degrees below zero in winter. With an average sunshine of 1,726 hours a year, it enjoys a long frost free period as long as 279.3 days per year on average.
Spring arrives March 22, which brings pleasant time back to the city featuring green crop fields, colorful flowers, butterflies during the day and the constant singing of frogs by the ponds at night. The dog days begin in the latter part of May, and the high temperature during this period make Changsha one of the "ovens" in China However, one may easily escape the heat to spend one's holidays in a number of summer resorts situated in the mountains located in the suburbs, where lakes, shade provided by trees and cool air make the dream of mid-summer come true. The date of September 19 usually heralds the arrival of autumn, when the leaves covering the mountains turn red, providing a sharp contrast with the crystal-blue water of the Xiangjiang River running nearby. Winter comes at the latter part of November. Changsha has a great deal of snow during winter. But the snow does not last long, giving way to the green vegetation again as soon as the sun re-appears.