January snowfall has improved the Snow Water Equivalent (SWE) situation in the Alps, but Italy still faces a -58% deficit, with severe criticalities in the Apennines. High temperatures and irregular precipitation are reshaping the snow balance: the country is experiencing “two winters in one,” with a stark North-South divide and another contrast between high and low altitudes.
We are in the heart of winter, and as Italy’s mountains approach the seasonal peak of snow accumulation, a complex and multifaceted picture emerges. While the Alps show signs of recovery compared to mid-January, the Snow Water Equivalent (SWE) deficit remains severe across the country (-58%), with particularly critical conditions in the Apennines. But what do the data tell us, and what can we expect in the coming months?
The delicate balance between precipitation and temperature
It is essential to remember that snow accumulation results from two key factors: the amount of precipitation and temperature trends. In January, Northern Italy experienced above-average precipitation, partially restoring snow cover in the Alps. However, in Central Italy, a lack of precipitation further worsened the situation, with a significant deficit along the Apennine ridge.
Beyond the lack of precipitation in the Apennines, the main issue remains temperature. Once again, January was warmer than average across the country. This played a decisive role in limiting snow accumulation: heavy precipitation did not translate into snowfall due to high temperatures but rather into rainfall even at unusually high altitudes.
“Temperature is the key factor at this stage, especially at mid-to-low elevations: given the same amount of precipitation, if temperatures are higher, the water that would typically be stored as snow and gradually released in spring and summer through melting enters the hydrological cycle immediately as surface runoff. In other words, the lack of snow accumulation results in a more irregular and less predictable water supply in the following months, potentially impacting ecosystems and human water use,” explains Francesco Avanzi, researcher at CIMA Research Foundation.
What does this mean for river basins?
North vs. South: the situation in major river basins
The Alps are showing signs of improvement compared to mid-January. In the Po River basin, snow cover is now slightly below average (-47%), close to the range of natural interannual variability. A similar scenario is observed in the Adige basin, with a -50% deficit and a slight recovery compared to previous data.
The situation is far more critical in the Apennines. In the Tiber River basin, for example, the deficit reaches -99%, with snow levels comparable to last year—one of the worst since 2011. This scenario is repeated in many other mountainous areas of Central Italy, where high temperatures and low precipitation have severely limited snow accumulation.
Two winters in one: the altitude paradox
While Northern Italy’s snow balance is more stable—placing the 2024-2025 winter season within the average of recent decades—the Apennines present a very different picture: here, the current season is among the worst in the past fourteen years.
We can speak of “two winters” when comparing the contrasting conditions between the North and Central-Southern Italy, but that’s not the only divide. As in recent years, this phenomenon is also evident in the sharp contrast between different elevation bands.
“At mid-to-low elevations, below 2000-2500 meters, the snow deficit is significant, with a considerable reduction in accumulation compared to historical averages. Here, higher temperatures have led to early melting and turned many snowfalls into rain, preventing the formation of a stable snowpack. As a result, the snow available to feed rivers in spring could be drastically reduced at these elevations, directly impacting water availability. At higher altitudes, the situation is different: in some cases, snow accumulation exceeds the average, as temperatures—while higher than normal—remain below freezing, allowing the snow to be preserved. This scenario highlights the crucial role of temperature in shaping not only snow distribution but also the overall water balance of mountain regions, with effects that will impact river flow and water resource management in the coming months,” Avanzi explains.
What to expect in the coming months?
Looking ahead, seasonal forecasts from ECMWF indicate significantly above-average temperatures across Europe from March to May. This does not favor snowpack preservation, which could melt earlier than the historical average. However, these forecasts remain uncertain and require continuous monitoring.
Regarding precipitation, the outlook appears more in line with seasonal averages. However, temperature will again be the decisive factor: will it be snow or rain? The answer to this question will determine the fate of the snow water resource and water availability for the spring and summer.
As March approaches, we enter the transition phase, when winter gives way to spring, and snow begins to melt, feeding rivers and watersheds. Some snowfall is expected in the Apennines over the upcoming weekend!
In the next updates, we will closely monitor this process to understand how the water currently stored as snow will spread through Italy’s hydrological systems.