Beijing and its neighboring Hebei Province and Tianjin Municipality were shrouded in dense fog on Wednesday, a day head of the country's much anticipated National Day parade.

Most of the southern part of Beijing and Hebei had visibility lower than 1,000 meters, according to weather offices in Beijing and Hebei.

"The fog on Wednesday is heavier than Tuesday, but it will be dispersed at the evening by rain, which will continue to 4:00-7:00 a.m. Thursday," said Guo Hu, director of the Beijing Meteorological Station.

He said if the wet weather continues Thursday morning, the department would consider taking weather modification measures to disperse the rain, depending on cloud conditions.

The People's Liberation Army air force said last Tuesday that it was taking steps to prevent rainfall and fog from dampening the parade.

A total of 18 carrier aircraft equipped with rain dispersing devices have been deployed in Hebei and Shanxi provinces next to Beijing, said Cui Lianqing, deputy director with the weather bureau of the PLA air forces headquarters.

Hebei has issued fog weather warning for the six days since Friday. Guo Yingchun, senior engineer of the Hebei weather station said that fog is frequent in autumn, when air humidity is high and winds are weak.