This dataset presents ERA5 daily downscaled surface air temperature and snowfall from two sites next to the first ice core drilled from Cordillera Darwin, Chile. These records were presented in Tetzner et al. (2025) to study regional-to-local environmental conditions at the firn core site. These local surface air temperature and snowfall estimations suggest the icefield has been progressively exposed to surface melt conditions, but not enough to produce significant melt at the firn core site. This dataset was created with the support of the Dieter R Tetzner''s National Geographic Early Career Grant 2019.

These datasets show how lake water-pressure fluctuated through time over several months in seasonally-frozen catchments in winter. These catchments were in three settings: the lowland Finnish Arctic, an alpine valley and a high cirque in Switzerland. The water-pressure data are accompanied by water temperature and (except for Orajarvi), ground temperature for the same periods. Together, they were used to detect and quantify the water content of snow falling on the lake surfaces. The locations, method of data collection and analysis and the results are described in detail in Pritchard, H. D., Farinotti, D., & Colwell, S. (2021). This work was funded by Natural Environment Research Council (UK) core funding to the British Antarctic Survey, and a fellowship from the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, CH-8903 Birmensdorf, Switzerland.