A procedure was used to calibrate the DSSATv3 CERES–Maize (Zea mays) model and to evaluate its performance in simulating growth and development of maize using input data collected from campesino farmers instead of using data obtained from on-station experiments or from the literature. The problems encountered in the calibration process are illustrated, particularly the failure of the model to simulate the growth and development of local highland maize cultivars (HMC). It is argued that the low ambient temperatures to which HMCs are exposed in the Toluca Valley are responsible for this failure, because HMCs respond differently to temperature and have a different optimum temperature range from temperate and tropical maize cultivars. It was concluded that the model needs to be adjusted to allow for consideration of the effects of constant low temperatures on the prediction of plant phenology and production, and partition of biomass in HMCs, since grain yield is not the main criterion used by smallholders when selecting maize cultivars.