Climatological normals of monthly and seasonnal are calculated using observation data from SADC Members. We calculated the climatological normals for observatories that have monthly data of more than 25 years for a given month. 

Climate Change Indices are based on daily temperature values or daily precipitation amount. Extremes such as the annual maximum daily precipitation amount or the daily maximum temperature of the month have traditionally been modelled with one of three different Extreme Value Distributions in engineering applications. The extremes used as climate change indicators have a much broader context. While some of the indices would fall within the traditional definition, most do not. It is important to make this distinction when analyzing indices since only a very few can be assumed to follow an extreme value distribution.