Data from experiments conducted in Hawaii, measuring soil surface temperatures in plots cropped with potato, cassava, and maize, were used to estimate soil surface temperatures using a model from the temperate zone. According to this model maximum soil surface temperature under a given vegetative cover can be estimated from maximum air temperature and a factor, Et, that represents the elevation of maximum soil surface temperature over maximum air temperature under that crop cover. Inputs for the model are: maximum air temperatures and plant biomass measurements. A generally good agreement between estimated and observed maximum soil surface temperatures was obtained when Et was arbitrarily set to 0.1 × Et. For potato during summer of 1985, maximum soil surface temperature estimates were within an average of less than 2C of observed surface temperatures and with a deviation of no more than 3.8C. For cassava during summer of 1986, estimates were within 2.3±5.1C; for maize during summer of 1988, estimates were within 2.7±4.4C.