What day is the Summer Solstice?

The summer solstice is one of the twenty-four solar terms. On June 21 or 22 of the Gregorian calendar, the sun runs to 90 degrees longitude (in Gemini). The position of the sun directly on the ground reaches the northernmost part of the year, almost directly on the Tropic of Cancer. At this time, the sunshine time in the northern hemisphere is the longest. In Beijing, the daytime hours can be as long as 15 hours. On this day, the northern hemisphere gets the most sunlight, nearly twice as much as the southern hemisphere.

What month and day is the summer solstice?

The summer solstice time of 2016 is from 06:34 on June 21, 2016 to 00:03 on July 7, 2016, Tuesday, May 17, 2016 in the lunar calendar.

The origin of summer solstice solar terms

The summer solstice is one of the earliest 24 solar terms to be determined. In the seventh century BC, the ancestors used Tugui to measure the shadow of the sun, which determined the summer solstice. The annual summer solstice begins on June 21 (or 22) and ends on July 7 (or 8). According to the Qur 'an,"the day of the Lord is near, and the day of the Lord is near." The ultimate is extreme." On the summer solstice, the sun reaches the northernmost point of the year, almost directly at the Tropic of Cancer (23°26 N), and the days in the Northern Hemisphere reach their longest, and the longer they go north, the longer they become. For example, the day in Haikou City of Hainan is about a little more than 13 hours, that in Hangzhou City is 14 hours, that in Beijing is about 15 hours, and that in Mohe of Heilongjiang can reach more than 17 hours. After the summer solstice, the position of the sun's direct light on the ground gradually moves southward, and the days in the northern hemisphere begin to shorten day by day. There is a folk saying that "eat summer solstice noodles, a short line a day". It was midwinter in the southern hemisphere.

Climatic characteristics of summer solstice

1. Convective weather: After the summer solstice, the ground is heated strongly, the air convection is strong, and thunderstorms are often formed from afternoon to evening. This kind of hot thunderstorm suddenly comes and goes, the rainfall scope is small, people call "summer rain separates the farmland ridge". Liu Yuxi, a poet of Tang Dynasty, once cleverly borrowed this kind of weather to write a famous poem: "sunrise in the east and rain in the west, the road is sunny but sunny." The heavy precipitation brought by convective weather is not as beautiful as described in the poem, but often brings local disasters. The poet Xu's letter "in the summer rain" in a poem, but also on the summer thunderstorm weather carried out a proper description: "summer smoke and heat sitting platform, frogs noise attack dust. A thunderbolt rings in the clear sky, and cold rain hits us like money."

2. Rainstorm weather: In most cases, during the summer solstice period, it is the middle and lower reaches of the Yangtze River and the Meiyu in the Jianghuai Basin. Heavy rain weather frequently occurs, which is easy to form floods and even poses a threat to people's lives and property. Attention should be paid to strengthening flood control work.

3. Meiyu in Jianghuai: The summer solstice season is the "plum rain" season in Jianghuai area. At this time, it is the yellow ripening period of plum in Jiangnan. The air is very humid. Cold and warm air masses meet here and form a low pressure trough, resulting in continuous rainy weather. In such weather, moldy objects, the human body also feel uncomfortable, some mosquitoes reproduce quickly, some intestinal bacteria are also easy to breed. At this time, we should pay attention to the hygiene of drinking water, try not to eat raw and cold food, and prevent the occurrence and spread of infectious diseases.

4, high temperature sauna: summer solstice and winter solstice are the same, are reflecting the seasons change solar terms. Astronomically, the summer solstice is the beginning of summer in the Northern Hemisphere. After the summer solstice, although the point of direct sunlight begins to move gradually southward from the Tropic of Cancer, the days in the Northern Hemisphere are getting shorter and the nights are getting longer. However, since the sun radiates heat to the ground more than the ground to the air, so in the future for some time, the temperature will continue to rise, so there is a "summer solstice but not hot" argument. According to the data from 1951 to 2006, the historical extremes of many northern cities appeared after the summer solstice.