In this paper, the temperature dependence of the turn-on characteristics of Schottky barrier diodes fabricated on oriented n-type β-Ga2O3 is reported. The barrier height (qΦbn) and ideality factor (n) for Ni- β-Ga2O3 was found to be 1.08 ± 0.05 eV and 1.19 respectively at room temperature. The effective Richardson constant (A**) is determined to be 42.96 A cm−2 K−2, in close agreement with the theoretical value. At low temperatures (85–273 K), the current–voltage characteristics reveal a strong temperature dependence of Schottky barrier heights and ideality factors and a corresponding deviation from the barrier height extracted from capacitance–voltage measurements. A detailed analysis is presented, which suggest that these effects can be attributed to a large barrier inhomogeneity at metal/β-Ga2O3 interfaces, possibly resulting from interfacial defects, which can be modeled using a potential fluctuation model.