Celebrated annually on 23 March in commemoration of the entry into force, in 1950, of the Convention of the World Meteorological Organization (WMO), and in celebration of the contribution of national meteorological and hydrological services to society, the 2015 World Meteorological Day will be held under the theme 'Climate Knowledge for Climate Action'. The Twitter hashtag for the day will be #WorldMetDay.  

date: 23 March 2015  
location: worldwide  
contact: WMO Secretariat  
phone: +41-22-730-8111  
fax: +41-22-730-8111  
e-mail: wmo@wmo.int  
www: http://www.wmo.int/worldmetday/