Understanding the coupled thermal-hydraulic behavior of unsaturated soils under freezing conditions is critical for assessing ground stability and moisture migration in seasonally frozen regions. This study presents a series of column freezing experiments on fully weathered Pisha sandstone, a highly erodible soil from the Loess Plateau, to investigate temperature, unfrozen water content, and matric suction evolution under unidirectional freezing with varying initial saturation. High-resolution sensors monitored changes along depth, enabling detailed analysis of freeze-induced processes. Results revealed a characteristic three-zone temperature structure: a frozen region near the cooling source, a steep transitional zone at the freezing front, and a deeper unfrozen zone. Higher initial saturation facilitated deeper thermal penetration due to enhanced thermal conductivity and latent heat effects. Unfrozen water content showed significant variation near the surface, decreasing with depth, and was strongly influenced by both saturation and temperature gradients. Matric suction exhibited two distinct trends: highsaturation soils displayed sharp increases in suction near the freezing front due to capillary effects during phase transition, while low-saturation soils experienced gradual increases linked to thinning interfacial water films. To predict these behaviors, a Gompertz-type model was developed to describe the equilibrium temperature profile, and a modified logistic model was proposed for suction-temperature relationships. Both models incorporate initial saturation as a key parameter and showed strong agreement with experimental results. The findings offer quantitative insights into freezing-induced water redistribution, with implications for modeling active-layer dynamics, seasonal frost infiltration, and groundwater-surface water exchange in seasonally frozen catchments.