In June 1960, the World Meteorological Organization (WMO) passed the resolution that 23 March should be celebrated as “World Meteorological Day”. Every year, a relevant theme is chosen by the WMO and the international meteorological sector for publicity and promotion. The purpose of holding World Meteorological Day is to enhance international awareness of the functions and activities of the WMO and the significant contributions of meteorological units to economy and national defence, as well as to promote application of meteorology in aviation, navigation, irrigation, agriculture and other human activities.