The winter that doesn’t come and the thirst of Sardinia

December 2025 is testing the calendar. In many parts of Italy, temperatures have remained stably above the seasonal average, with mild days, clear skies and weather more reminiscent of March than the heart of winter. In the South and on the islands there was no shortage of highs near 20 degrees, whilst even in the Centre the cold remained confined to a few hours at night.

Dominating the scene is a persistent anticyclone, blocking the arrival of Atlantic disturbances and keeping cold currents away. The result is a “suspended” winter: little snow in the mountains, scanty rainfall and a widespread feeling of climatic anomaly that is no longer surprising, but continues to worry.

Abnormally hot, absent rainfall

The problem is not only the thermometer. The most critical aspect is the lack of precipitation, especially in some already water fragile regions. Without rainfall and snow, water reserves do not recharge , and rivers enter the winter season with reduced flows.

In the plains, the stagnant situation also worsens air quality, whilst in the mountains, the scarcity of snow compromises the water storage that should feed rivers and reservoirs in the following months. It is a domino effect that is slowly but increasingly evident.

Sardinia case: Lake Omodeo recedes

In Sardinia, the emergency is already a reality. Lake Omodeo, the island’s largest man-made reservoir and one of Italy’s main water reservoirs, is experiencing a phase of severe reduction in levels. The banks are receding, vast portions of the seabed remain uncovered, and the amount of available water continues to decrease.

The basin is a strategic hub for water supply, agriculture and energy production. Its gradual emptying is the most visible sign of a long-lasting crisis, aggravated by increasingly hot summers and winters unable to recharge reserves.

Not just emergency, but a structural signal

What is happening at Lake Omodeo is a reflection of a Mediterranean that is warming up faster than the global average, with less and less recognisable seasons and an increasing alternation between prolonged droughts and extreme events.December’s warmth, in this sense, is just the latest tile in a larger mosaic: less rain when it is needed, more stress on ecosystems, and water management that is becoming more complex every year.

Italy experiencing an almost spring-like December may well appreciate the momentary warmth, but the price is paid elsewhere: in thirsty fields, in reservoirs that empty, in water reserves that do not replenish. The Lake Omodeo crisis is a concrete reminder: climate change is a reality affecting taps, crops and everyday choices.