A non-price determinant of demand is a force outside of supply that affects the demand for a product. For example, ice cream is in lower demand in winter than it is in summer because customers want it less when it is cold. Therefore, a change in weather is a non-price determinant that affects the price of ice cream. Other non-price determinants of demand include price of substitute products and complementary goods, income, expectations, and tastes and choices or preferences.