五月中,夏,假也,至,极也,万物于此皆假大而至极也。——《月令七十二候集解》夏至是北半球一年中白昼最长、黑夜最短的一天。夏至日那天,整个地球上除北极点和南极圈内的极夜地区外,所有地点的日出方向都是从东北方开始的,在西北方落下。夏至是一年“四时”之一,标志盛夏的来临。与冬至开始数九一样夏至起也数“夏九九”。夏至来临之时,长江中下游地区一般已进入梅雨季 May, summer, fake also, to, very, everything in this fake big but also extremely. - “Monuments seventy-two solution” The summer solstice is the longest day in the northern hemisphere one year, the shortest day of the night. On the summer solstice day, the sunrise on all locations, except the North Pole and the polar night in the Antarctic Circle, all started on the northeast and fell northwest. The summer solstice is one of the year “four o’clock ”, marking the advent of summer. And the beginning of the winter solstice nine summer solstice from the same number of “summer nine nine”. When the summer solstice is approaching, the middle and lower reaches of the Yangtze River have generally entered the rainy season