In tropic, the weather/climate that very effect to crop production variability is rainfall because of it has variability according location and time. Therefore, rainfall and theother climate in it correlation with crop production need minimum data periods, so accuracy analysis and a valid decision can be taken. Methods is minimum periods length analysis. Analysis of climate data in South Kalimantan shows that minimum data must be more than 20 years. Keywords : Climate data, ENSO, Minimum data periods