The data (EPSG:32627 - WGS 84 / UTM zone 27N; resolution 30x30 m) show the perennial snow patch distribution in six case study areas on Tröllaskagi peninsula, northern Iceland (see Further Details, Map Overview).We use freely available optical satellite images (Landsat-5/-7/-8 and Sentinel-2) for the mapping the snow patches (see Further Details, Table 1). Therefore, the Normalized Difference Snow Index (NDSI) is calculated for end of summer season images. For each case study area five time periods are calculated. The results are compared to aerial photos, orthophotos and photos from field work as well as to available temperature, precipitation and wind data from several weather stations.