The volume of world climatological data for 19611990 is now available from WMO*. The publication contains monthly and annual statistical data on a number of climatological elements for more than 4 000 stations in some 140 countries. The 30-year standards are defined by WMO Technical Regulations as "averages of climatological data computed for the following consecutive periods of 30 years: 1 January 1901 to 31 December 1930, 1 January 1931 to 31 December 1960, etc.".
