One of the biggest causes of decreased algae production in open ponds is diurnal and seasonal temperature variation. The ARID (Algae Raceway Integrated Design) system maintains temperature in the optimal range by controlling the surface area of the system. A finite difference temperature model of the ARID raceway was developed in Visual Basic for Applications. The atmospheric boundary layer model uses hourly meteorological data from agricultural weather station networks. The latent heat of vaporization is calculated with the weather station reported values of evapotranspiration, which are calculated with the ASCE standardized Penman equation. The energy balance includes four terms: solar radiation, sensible heat flux, latent heat of vaporization, and long wave radiation. This research focused on calibrating the model for a one month experiment that was run during winter 2011. The results show a very good match between the simulated and the experimental temperature. The model was run in order to simulate the temperature and algae growth in ARID and conventional raceways in Tucson and Yuma, Arizona during the 12 months of 2011.