Thunderstorms had threatened the closing ceremony of the Beijing Olympics, but planes spreading rain dispersal materials were dispatched and rockets were fired to ensure that no rain fell during the ceremony, said Chinese weather officials.

"Rain clouds from Hebei and Inner Mongolia had started to move towards the capital city at 2 p.m.," said Guo Hu, head of the Beijing Observatory.

"Moisture in the air was at a higher level than at the time before the opening ceremony and would more easily develop into convective clouds," said Zhang Qiang, from the Beijing Weather Modification Office.

"We decided to use planes to cover a larger area, along with firing rain dispersal rockets from the ground."

Eight planes were dispatched from Zhangjiakou City in neighboring Hebei Province and the outskirts of Beijing to disperse chemicals between 2 p.m. and 8:50 p.m.

In addition, 241 rocket shells were fired in nine rounds from Beijing, Tianjin and Hebei to disperse the rain clouds.

The city also set off more than 1,000 rain dispersal rockets on the evening of the opening ceremony of the Games.