The shift of the equilibrium-line altitude by climatic perturbations of air temperature δT
a, absolute humidity δρv, cloudiness δw and annual accumulation 6c in West Greenland (EGIG profile) is analyzed by heat-balance modelling. The perturbations δT
a = +1 K, δρv = +0.25 g m−3, δc = +50 kg m−2 result in a shift of the equilibrium-line altitude of 87.5, 9.8, and −24.3 m, respectively, while perturbations in cloudiness are negligible. The most important influence originates from changing air temperature, as air temperature affects daily heat-flux density of melt and duration of the ablation period. In regimes with negative values of the gradient of annual accumulation, the shift of the equilibrium line is enhanced.