The characteristics of automatic weather stations (AWS) operation efficiency are discussed, by means of the data from 81 AWS stations over Anhui Province monitored by the Atmospheric Observing System Operations and Monitoring (ASOM), and the arrival rate and availability of AWS operation data in 2010 are statistically estimated. The statistical characteristics of operation efficiency of standard stations, basic stations, and general stations are studied month by month, and the influencing factors on operation availability are also analyzed, in allusion to the characteristics of the format error cases of data. The quantificational relation between data format errors and human computer interaction is studied emphatically, and it is determined that the quantificational threshold of data transmitting time is less that 45 seconds. In order to improve the performance and data quality of AWSs, some feasible measures are presented for eliminating format errors.