A spring wheat growth model (SUCROS-87) was used to identify moisture stress periods during the growing seasons and simulate yield potentials of durum wheat (Triticum turgidum var. durum) in six durum wheat growing regions of Ethiopia. The start of the rainy season and distribution of rainfall were erratic, particularly in the low-altitude regions. As a result, simulated dates of emergence varied from June to August. Moisture stresses of various intensities, at different growth stages of the plant, were limiting to durum wheat production in all the regions except Debre Markos. Terminal moisture stress was simulated in 7 out of 10 years in all locations except Debre Markos, whereas intermittent stress. was simulated in three locations in 2 out of 10 years. In Metahara rain-fed durum wheat production is not feasible without irrigation. Water use efficiency decreased with decreasing rainfall but the transpiration coefficient increased. The average simulated potential grain yields at all the locations were high (6600 kg ha−1) compared with the actual national average. Development of versatile and region-specific improvement strategies are emphasized to improve durum wheat production in the country.