This dataset includes observational data from Nigardsbreen that were collected from 10 September to 20 October 2023 with a focus on 12-14 September. The measurements are based on automatic weather stations, a LiDAR wind scanner, radiosondes, uncrewed automatic vehicles (UAVs), and temperature and humidity loggers. The observations are supported by numerical simulations of 333 m horizontal resolution from the Weather Research and Forecasting (WRF) model, including model sensitivity experiments using different glacial lake surface temperatures and glacier extent.