Xiamen has a subtropical climate. It is generally mild and temperate with abundant rainwater. It has an average annual temperature of approximately 21℃. Winter in Xiamen is not harsh while summer is free from extreme heat. The city has an average annual rainfall of about 1200mm, mainly concentrated on the months from May to August. Wind power measures between Grade 3 to 4 in general, with northeast wind representing the dominant wind direction. Because of the air currents resulting from the difference in temperature in the Pacific, Xiamen is affected by typhoon three to four times annually on average, which mainly comes during the months from July to September.