The spectral induced polarization dataset contains four separate files, each corresponding to one of the four pore water conductivity levels: 0.05 S/m, 0.1 S/m, 0.35 S/m, and 0.7 S/m. Each file contains four sheets, corresponding to the used sand-clay samples with clay contents of 2%, 4%, 6%, and 8%. Within each sheet, the in-phase conductivity (σ′) and the quadrature conductivity (σ′′) are reported as functions of measurement frequency for each saturation level. These results are published in Iván et al. (2026): Distinguishing water salinity, water saturation and clay content using Spectral Induced Polarization: a tool for monitoring arid soil conditions