Snowfall in Greece's mountains plays a critical role in the country's hydrological cycle, helping replenish the water reserves that sustain agriculture, ecosystems and household consumption. But scientists warn that snow cover across several of the country's highest peaks has declined sharply in recent decades, reflecting the growing influence of climate change on winter weather patterns.
New observations from the Hellenic Mountain Observatory highlight the scale of the shift. A scientific expedition to Mount Grammos in northern Greece this February recorded unusually limited seasonal snow cover on the mountain's slopes. Researchers say the reduced snowpack could affect water availability in the headwaters of the Aliakmonas River, Greece's longest river, which originates in the Grammos range.
"The trends of recent years show that the role of snow is changing," said Konstantis Alexopoulos, director of the Hellenic Mountain Observatory. "Although conditions vary from year to year, with some winters bringing more snow and others significantly less, the overall trend is downward and is clearly due to rising temperatures."
Recent analyses from the observatory indicate that this winter demonstrates how rising temperatures are altering precipitation patterns across Greece's mountains. Over the past 30 years, many mountainous areas have experienced rainfall significantly above average between November and February, in some cases up to 100% more, including in the Northern Pindus range in January and on Mount Chelmos in February.
However, unusually warm conditions meant that much of this precipitation fell as rain rather than snow. Temperatures during recent months were between +1°C and +2.5°C above seasonal averages, pushing the snowline higher and limiting snowfall largely to elevations above 2,000 metres.
At the same time, warmer conditions and frequent rainfall have accelerated the melting of existing snowpack. Across mountain regions nationwide, the average extent of snow cover has dropped well below the 30-year average - about 58% lower at the start of winter and 31% lower by February.
Another factor worsening the situation is the deposition of Saharan dust on snow-covered slopes. According to Alexopoulos, this layer darkens the surface, reduces snow reflectivity, increases solar absorption, and speeds up melting. "The recent coverage of snow-covered areas by African dust has reduced the reflectivity of the snow and therefore increased the absorption of solar radiation," he explained.
Researchers now expect that the combination of reduced snow cover and dust deposition will likely lead to earlier snowmelt this spring, even if additional snowfall occurs in March or April. The Hellenic Mountain Observatory continues to monitor changes in mountain snowfall in cooperation with METEO, the National Observatory of Athens, and the University of Cambridge, as scientists seek to understand how warming winters may reshape Greece's water resources in the decades ahead.
By Nikos Avoukatos - adapted from Greek by Vassia Barba
