Chengdu enjoys a subtropical monsoon climate, having warm and humid weather all year around. There are four discernable seasons, with an average annual temperature of 16 degrees centigrade and an average annual rainfall of 1,000 mm. Chengdu enjoys a frost-free period of over 300 days a year, experiencing sunshine for an average of over 1,200 hours yearly. Because it has long been endowed with a mild climate that is free form blood or drought, it has a vast amount of fertile land, rich in produce and prosperous industries. Therefore, Chengdu has been referred to since ancient times as the "Land of Abundance".