What is the shortest day and the longest night in a year?

The shortest day and the longest night in a year are winter solstice. The winter solstice is June 65438+February 2 1 ~ 23 in Gregorian calendar every year. It is worth noting that around the winter solstice, the earth is located near the perihelion, and its running speed is slightly faster, resulting in that the time of direct sunlight in the southern hemisphere is about 8 days shorter than that in the northern hemisphere in a year, so the winter in the northern hemisphere is slightly shorter than that in summer.

On the day of winter solstice, the sun moves to 270 degrees of the yellow meridian (winter solstice), and the position of the sun directly on the ground reaches the southernmost point of the year. The sun is almost direct to the Tropic of Capricorn (also known as the winter solstice daily line), and the sun is most biased towards the northern hemisphere. Therefore, in all parts of the northern hemisphere, the winter solstice is the shortest day in a year, and the farther north, the shorter the day.

Study on climatic characteristics of winter solstice with extended data;

Climatically, during the winter solstice, the average temperature in the northwest plateau is generally below 0℃, and the southern region is only about 6℃ to 8℃. In addition, the winter solstice begins to count to nine, and the winter solstice becomes the first day to count to nine.

As for "Counting Nine", there is a folk song that goes like this: "Don't do it in September, walk on the ice in March and April, watch the willows along the river in May and June, open the river in July and September, geese come in August and September, and cows go everywhere in September and September." However, in the southwest low-altitude valley area, even in the coldest local165438+ in early October, the average temperature is still above 10℃. It can be said that autumn goes and spring comes, and there is no winter all year round.