The BACSAM II aircraft campaign, conducted with the polar research aircraft Polar 6 and the towed body T-Bird, took place from 3 April to 2 May 2024. It was based in Longyearbyen, Svalbard. In total, 11 low-level research flights and two transit flights were conducted, covering the region around Svalbard and north of Greenland.The datasets present upward and downward shortwave and longwave irradiance measurements, together with the corresponding sensor temperatures and GPS position. One pyranometer and one pyrgeometer were installed on the top of Polar 6, with an additional pyranometer and pyrgeometer installed on the underside of the aircraft. For convenience, the dataset also provides pitch and roll angles.