Spatially and temporally complete snow cover percent is interpolated (Rittger et al, 2019) from Moderate Resolution Imaging Spectroradiometer (MODIS) snow covered area and grain size (MODSCAG) model (Painter et al, 2009). Satellite observations that look straight down are weighted more heavily in the interpolation than satellite views from an angle. Interpolation also adjusts the snow cover percent when tree canopies block the snow surface.