This study aims to determine areas with potential for growing common bean, excluding mainly the areas not recommended for the crop due to low temperatures. The agricultural zoning of the Rio Grande do Sul and Santa Catarina states, Brazil, and the reanalysis of that zoning, elaborated in the Macrozoneamento Agroecológico e Econômico do Rio Grande do Su, was used..

The determination of the favorable sowing periods was based on calculations of daily water balance, considering the interaction among locations (climate) x cycle of the varieties x sowing period x soil type. The Sarrazon software was used to calculate the daily water balance using a database from 15 to 20 years of daily rainfall measurements of 251 weather stations. Simulations were run for sowing dates on days 5, 15 and 25 of every month, from August to February. For the simulations of the water balance three cycles of the common bean cultivars were considered (90, 100, and 110 days) and three types of soils, with soil water availability of 35 mm, 50 mm, and 70 mm. The crop water requirement index (ISNA) was used as main zoning index. The values of ISNA, calculated for a minimum frequency of 80%, were plotted with the SPRING Geographic Information System being defined three categories: favorable (ISNA > 0.60), intermediate (ISNA between 0.60 and 0.50), and unfavorable (ISNA < 0.50). The sowing periods were established based on the areas defined by favorable ISNA values.