What is the shortest day?

The shortest day is the solstice in winter.

The shortest day is the winter solstice, which is the shortest day and the longest night in a year. The winter solstice is one of the 24 solar terms, usually between 65438+February 2 1-23 every year. At this time, the northern hemisphere of the earth is the farthest from the sun and receives the least direct angle from the sun, so the day time is the shortest and the night time is the longest.

On the solstice of winter, the sun is almost above the tropic of Capricorn, and the elevation angle of the sun in the northern hemisphere is the smallest and the oblique angle of the sun is the largest, which makes the daytime very short. In addition, during the winter solstice, the sunshine time on the earth is also the shortest, which is one of the reasons why the daytime time is shortened. Although the winter solstice is the shortest day in a year, it doesn't mean that it is the only day with shorter days.

Climatic characteristics of winter solstice

1. Shortest day: The winter solstice is the shortest day in a year. Because the direct angle of the sun is the smallest and the oblique angle of the sun is the largest, the day time is shorter and the night time is longer.

2. Temperature drop: The solstice in winter is the beginning of winter. With the decrease of solar radiation, the heat gained on the ground decreases correspondingly, and the temperature drops gradually. At the same time, cold air activities are frequent, and weather phenomena such as low temperature, frost and freezing are prone to occur.

3. Sparse precipitation: During the winter solstice, due to the low temperature, the water vapor in the air is easy to condense into frost, fog, snow and other weather phenomena, but the precipitation is relatively small.

4. Increased wind power: In winter, due to the change of pressure gradient, the wind power gradually increases, which is prone to windy weather. In northern China, cold waves, strong winds, sandstorms and other weather phenomena are prone to occur during the winter solstice.