Spatial and temporal averaging of observational data is widely used in many problems of meteorology, hydrology and related sciences. Several averaging methods have been proposed by various scientists and are used on a regular basis to obtain data averaged in space orfand in time, to yield data which are less influenced by random factors than initial point data are. The significance of averaging meteorological fields has substantially increased nowadays in connection with the problem of global climate change. However important as such change may be, it is very small as compared with the...