Book Description: Despite the rapid development of statistical packages, a lot of climatic data still remain unanalyzed due to lack of specialized routines in most of the packages. One package has a climatic menu though with limitation on complex analysis such as generalized linear models. Others can perform the Generalized Linear Model analysis but do not have a specialized menu for analyzing climatic data. There is no statistical package currently available which has a specialized capability to do climatic analysis easily and includes the use of generalized linear models. This study starts the work of creating a specialized menu in GenStat for analyzing climatic data by implementing Markov modeling of rainfall data. Four procedures have been written and corresponding dialogues were created to ease their use. Incorporating a climatic menu into GenStat package will support researchers in agricultural and many other fields that need an analysis of climatic data as part of their work.