This technical extension guide developed by ICRAF and partner institutions explains simple methods for measuring actual rainfall in farming areas, especially in rainfed agriculture and mountainous regions. The document highlights the importance of real rainfall data for farmers and extension workers to make better decisions on planting time, crop management, fertilization, and climate adaptation. According to FAO recommendations, sowing should begin only when rainfall reaches at least 30 mm to ensure sufficient soil moisture for seed germination. The guide introduces a low-cost manual rain gauge using common materials such as a funnel, bottle, measuring cup, and bamboo pole. It also explains how to calculate rainfall using collected water volume and funnel area. In addition, the document recommends using smartphone applications such as Vrain to monitor rainfall from nearby weather stations. The guide supports sustainable agroforestry, climate resilience, and improved agricultural planning in sloping lands of Southeast Asia.
