Abstract Snow crystals have a rich diversity of forms with striking hexagonal symmetry. The two-dimensional types include dendrite, stellar, sector and plate forms. Physical studies have shown that the particular form of a snow crystal is dependent upon the temperature and saturation in the growth environment. We investigate a simple, local, two-dimensional model that has just two parameters exhibiting the desired diversity. The dendrite growth is especially realistic. We use the model to investigate the impact of varying conditions of growth