What kind of weather is foggy in the Northeast?

Winter. Winter in the Northeast is mainly caused by cold air from high latitudes frequently moving southward, causing water vapor in the atmosphere to condense. As we all know, most of the Northeastern region has a temperate monsoon climate. It is close to the ocean, has large areas of humid and semi-humid areas, and has relatively high water vapor content in the atmosphere. In winter, when cold air encounters, it will condense and form heavy fog.