Greenland is closing in on three decades of continuous annual ice loss, with 1995-96 being the last year in which the giant ice sheet grew in size. With another melt season over, Greenland lost 105bn tonnes of ice in 2024-25. The past year has seen some notable events, including ongoing ice melt into the month of September – well beyond the end of August when Greenland’s short summer typically draws to a close. In a hypothetical world not impacted by human-caused climate change, ice melt in Greenland would rarely occur in September – and, if it did, it would generally be confined to the south. In this article, we explore how Greenland’s ice sheets fared over the 12 months to August 2025, including the evidence that the territory’s summer melting season is lengthening. (For our previous analyses of Greenland’s ice cover, see coverage in 2024, 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016 and 2015.) Surface mass balance The seasons in Greenland are overwhelmingly dominated by winter. The bitterly cold, dark winter lasts up to ten months, depending on where you are. In contrast, the summer period is generally rather short, starting in late May in southern Greenland and in June in the north, before ending in late August. Greenland’s annual ice cycle is typically measured from 1 September through to the end of August. This is because the ice sheet largely gains snow on the surface from September, accumulating ice through autumn, winter and into spring. Then, as temperatures…
