Dust weather records in Beijing during 1860–1898 AD based on the Diary of Tonghe Weng

The Diary of Tonghe Weng, a famous Chinese historical diary, is found to be an enormously valuable historical resource for historical dust weather researches. It contains a body of daily observations of the dust weather in Beijing during 1860–1898 AD. The continuity and reliability of the dust weather records are evaluated. The data absences amount to a little more than 9%. A total of 349 dusty days are identified, thus the annual average is about 9 days. However, the true average of the annual total of dusty days in Beijing during 1860–1898 AD would be a little more than 9 days due to data absences.