The term climate normal, referred to a climatic element at a place, designates the mean value corresponding to a number of years large enough to be considered as representative of the prevailing value of that element at the place under consideration.
For the purpose, the World Meteorological Organization (WMM) established 30 years, beginning in the first year of each decade (1901-30,..., 1931-60, 1941-70,..., 1961-90, 1971-2000).
The statistical results respecting these time intervals are usually called Climate Normals, the normals for 1931-60 and 1961-90 being considered as the reference normals.
The Climate Form shown for each climatological station selected contains the monthly and annual values of some of the main climate parameters in the form of graphs and table: mean values; maximum and minimum air temperature; precipitation; sunshine; wind; extreme values of maximum and minimum air temperature.