Empirical equations have been developed to predict the mechanical properties of greenhouse films when exposed to natural weather conditions for long durations. Tensile strength and percent elongation data obtained for the Dhahran site was used to develop empirical equations. Prediction models were developed with exposure time as independent parameter for both tensile strength and percent elongation, which were taken as dependent parameter. The mean deviations for tensile strength and percent elongation were found to be 2.5 and 1.2%, respectively. Weather data of Dhahran for the period of natural exposure is also presented.