This data collection presents snow depth, ice thickness and RADARSAT-2 (RS2) and TerraSAR-X (TSX) backscattering coefficient data over selected homogenous first-year smooth and undeformed sea ice areas in Salluit, Deception Bay and Kangiqsujuaq. These study sites are fjords of the Hudson Strait located in Nunavik. The data covers three winter seasons: 2016, 2017, 2018. Snow depth and ice thicknesses were measured at roughly 30 locations covering each site, twice per season (in January-February and April-May), by direct measurements. High-resolution SAR images were acquired from December to May every 24 days for RS2 and every 11 days for TSX. Data is presented for HH, HV, VV, co-polarization ratios and Cloude-Pottier decomposition parameters for the Wide-Fine Quad-Pol RS2 data, and for the HH backscattering coefficient for the Stripmap TSX data. These acquisitions were made to explore the relationship between snow depth, ice thickness and SAR. For the "SAR parameter statistics at AOI for RADARSAT-2 and TerraSAR-X" dataset, pixel median value was computed over areas of interest (AOIs) roughly 120 by 100 m and each containing between 600 and 650 pixels were distributed over the homogeneous study areas in a grid-like pattern with 0.7 to 1 km separation, avoiding special features like the shore or a ship's track. The Salluit, Deception Bay, and Kangiqsujuaq study areas counted 35, 43, and 78 AOIs, respectively. For the "SAR parameter values at measurement locations" files, pixel values were averaged over a 3x3 window for RS2 (576 m2) and a 9x9 window for TSX (506 m2). This data collection contains supplementary materials to Dufour-Beauséjour et al (2021).