Surface Climatology of Glaciers in Iceland: Icelandic Glaciers Automatic Weather Station Network (ICE‐GAWS)

Abstract This study shares over 25 years of weather and climate data collected from Iceland's glaciers. Since 1994, scientists have recorded weather observations from stations installed on the glaciers. These records help understand how the local climate is changing and implications for glacier melt. The weather station network covers many parts of the glaciers, especially on Vatnajökull, Iceland's largest ice cap. It captures conditions in the accumulation areas where ice builds up, to the ablation areas where ice melts. For other glaciers, the data give a broader look at regional climate patterns. The results show that winters were coldest from December to February, and summers were warmest in July and August. Winter temperatures ranged from around 0°C near the coast to −10°C at higher elevations. Summer temperatures were above freezing at nearly all sites, which allows melting to occur. One sign of increased melting was a rise in “Positive Degree Days,” days warm enough to melt ice. These were more common at lower elevations and near the coast. Another sign was that glacier surfaces were getting darker in spring, especially in places with thinner winter snow. Darker surfaces absorb more sunlight, leading to faster melting. Volcanic ash and airborne dust have also darkened glacier surfaces in some years. By keeping track of these changes, this study helps to understand how Iceland's glaciers are responding to a warming climate—and why continued long‐term observations are essential.