The Summer Solstice occurs exactly when the Earth's axial tilt is closest to the sun, at its maximum angle of 23°26'. On that day, daytime lasts its longest for the whole year in the northern hemisphere. After the day of Summer Solstice, daytime begins to become shorter and shorter in the northern hemisphere. That's why there is a folk saying which goes, "After eating the Summer Solstice noodles, daytime becomes shorter and shorter".

How long is the day on Summer Solstice exactly? According to an expert, the whole day, including the morning twilight and the afterglow, is 16 hours long.

The days become shorter and shorter, and temperatures higher and higher after the Summer Solstice. When the three periods of hot season come, it is the hottest time of the year.