The Po Valley is an area in northern Italy running from the Western Alps to the Adriatic Sea.
One of the characteristic of the region is the presence of fog during the fall and winter period.
Because of climate change fog in the Po Valley has reduced by a half over the last twenty years.

The Po Valley is a large plain in northern Italy that is home to a number of major cities, including Milan, Turin, and Bologna. The valley is also known for its frequent fog, which can be a mysterious and beautiful phenomenon.
The fog in the Po Valley is caused by a combination of factors, including:
The cold air from the Alps: The Alps are a mountain range that runs along the northern border of Italy. The cold air from the Alps can flow down into the Po Valley, creating ideal conditions for fog formation.
The warm air from the Mediterranean Sea: The Mediterranean Sea is a warm body of water that lies to the south of Italy. The warm air from the Mediterranean Sea can flow into the Po Valley, creating a temperature inversion. A temperature inversion occurs when the temperature of the air rises with altitude. This can cause the water vapor in the air to condense, forming fog.
The flat terrain of the Po Valley: The Po Valley is a flat plain, which makes it easy for fog to form and spread.
The fog can have a significant impact on the Po Valley. It can make it difficult to see, which can be a safety hazard for drivers and pedestrians. The fog can also disrupt transportation and other activities.
However, the fog can also be a beautiful sight. It can create a sense of mystery and romance. The fog can also be a good time for photographers to capture stunning images.