This paper reports an experimental investigation of the thermal properties of frozen tap, demineralized, and sea water. The presented research assists in a better understanding of the thermal properties of ice and the processes within it and contributes regarding the generation of novel experimental data. The thermal conductivity was measured in a range from −14 °C to −33 °C using the Transient Plane Source (TPS) method. Ice blocks were placed in an expanded polystyrene box in the freezer, which is where the measurements took place. The thermal conductivity of the tap water ice was observed to vary in a range from 1.915 ± 0.005 Wm−1K−1 at −14 °C to 2.060 ± 0.004 Wm−1K−1 at −33 °C. The values obtained for the ice made of demineralized water differed by less than 10%. The thermal conductivity of the sea ice was shown to be more temperature dependent, with the values ranging from 1.262 ± 0.005 Wm−1K−1 at −14 °C to 1.970 Wm−1K−1 ± 0.004 at −33 °C. A noticeable fall in the thermal conductivity of the sea ice was observed in the temperature range from −26 °C to −19 °C. A possible reason for this could be the increased precipitation of salt in that temperature range. Measurements of thermal diffusivity displayed similar trends as those of thermal conductivity. Specific volumetric heat capacity was indirectly calculated.