The Mogao Grottoes, a world heritage site in northwest China's Gansu Province, reopened to visitors Friday after temporarily closing for two days due to torrential rains, according to local sources.

Humidity in the air has decreased to normal levels, said Ji Xinming, Party secretary of the Dunhuang Academy, which is responsible for the research, protection and management of the heritage site.

"Due to consecutive torrential rains, humidity in the caves has exceeded the set limit. The temporary closure was imposed to protect the grottoes' interior murals," said Ji.

The torrential rains did not adversely impact the caves in any other way, apart from damaging roads near the site, said Ji.

The Mogao Grottoes, or the Ancient Caves of 1,000 Buddhas, were listed in 1987 by the United Nations' Educational, Scientific, and Cultural Organization as China's first world heritage site.