The main objective of this article was to study the physical and mechanical properties of watermelon fruits as influenced by storage temperatures. Watermelon fruits with different sizes were stored at two temperatures (15 and 30°C). The results indicated that, the length, major diameter and minor diameter of watermelon fruit value ranged from 22.18 to 28.77 cm, 21.34 to 27.07 cm and 18.92 to 23.01cm, respectively. The spherical coefficient and the geometric mean diameter of the watermelon fruits decreased from 0.933 to 0.907 and 20.70 to 26.08 cm, respectively. The surface area and volume of watermelon fruit values ranged from 1487.10 to 2447.61cm2 and 5393.90 to 11389.44 cm3, respectively. The density of the watermelon fruits ranged from 927.84 to 973.57 kg m-3. The thickness of rind of the watermelon fruits ranged from 12.11 to 20.28 mm. The mass of flesh, seeds and rind of watermelon fruit values ranged from 2.929 to 6.277 kg, 0.096 to 0.208 kg and 1.992 to 4.603 kg, respectively. The repose angle and the crushing load of the watermelon fruits increased from 49.67 to 71.00º and 2.333 to 4.600 kN. The change of watermelon fruits dimensions and weight decreased with increasing storage temperature and time. The crushing load of the watermelon fruits decreases with decreasing storage temperature and decreasing watermelon fruit sizes. The marketable watermelon fruits percentage ranged from 75.67 to 90.00% at 15 ºC and from 25.00 to 48.00% at 30ºC.