Today is China's traditional summer solstice day, marking the day with the most daylight and shortest night.

Following the summer solstice, the days begin to shorten, the temperature rises in north China and there's plenty of sunshine and rain, all of which is good for crops. The middle and lower reaches of the Yangtze River are in the rainy season, during which persistent and heavy rains are common.

The hottest days of summer begin after the summer solstice and come in three stages with each period lasting for about 10 days.

Wang Yumin, assistant research fellow, Beijing Planetarium, said, "In Beijing, the daytime between the sunrise and sunset is about 15 hours on the Summer Solstice Day. And if adding the hours of sunshine, it will totally reach 16 hours around."

(CCTV June 22, 2009)