At a time when life hinges on weather-dependant harvest, a long drought could be a life-and-death issue for Chinese farmers. As such, praying for rain became a grand sacrificial ritual in former times.

In old China, the Dragon King was believed to be in charge of rain, and good weather for the crops was thought to be solely reliant on him. So the Dragon King was highly respected, and nobody dared to offend him in any way. In the past, on the 18th day of every lunar June, an imaginary birthday of the Dragon King, temple fairs at Dragon King Temples would be held in all parts of the country to pray for rain.

Some farmers thought that the Dragon King was not the only one controlling the rain; other deities like Goddess of Mercy, God of Water and Lord Guan were also in charge. Once there was drought, temples dedicated to Goddess of Mercy and Lord Guan were packed with worshipers burning lots of incense there.

Apart from burning incense at temples, there was a custom of carrying the Dragon King's image around all villages as a rain-praying ritual. People would prepare a water jar with willow branches inside and place it in front of the door. And a yellow paper sheet bearing characters meaning "the memorial tablet of the Dragon King controlling nine streams, eight rivers, five lakes and four seas" was stuck to the jar, in front of which incense was burned and offerings were presented. When the Dragon King's image-carrying procession passed by, people would spray water from the jar onto the procession. When they passed by a well, people in the procession would kneel down and pay homage to the well, crying out loud "please give us rain". All members in the procession must be men and they were supposed to be barefooted and wearing a wicker cap.    

There was another even older rain-praying ritual called "collecting water". In some parts of Shandong, the whole village would begin a fast three days before the ritual. All participants of the ritual must be men and they should wear a wicker cap. On the day of the ritual, the men would respectfully bring the sculpture of the Jade Emperor out of the temple and put it into a sedan chair. Carrying the sedan chair and holding a flag, a big procession would march toward a pond far away. When arrived at the pond, they would put water into a bottle prepared beforehand and would catch a crucian carp and put it into the bottle, symbolizing the coming of a sudden rain, as a cucian carp is "ji yu" in Chinese, which sounds the same as another phrase meaning "sudden rain". After returning to the village, they would chant sutras for three days.

In some areas, people would kind of force the Dragon King or other deities to bring rain. In places like Jixian of Hebei and Fuyang of Zhejiang, people would carry the deity sculpture out the temple and expose it to the blazing sun. They thought that if the deity suffered a little, he wouldn't be able to stand and would then bring down the rain. This custom may have been formed as an irritated reaction to all deities after pious but useless worship.

Praying for rain was a reflection of ancient people's inability to control natural forces. As society progresses, scientific power has been helping people to fight drought. As a result, the Dragon King and other deities have lost their power and prestige.