The diurnal variation characteristics of microwave radiometer measurement deviation and the time series are analyzed by using the high temporal spatial resolution radiosonde data (3 h, 30 m in vertical) and the corresponding MP 3000A microwave radiometer data of Wuhan. The results show that the measurements of atmospheric elements have higher accuracy, but there are still some deviations. The large values of temperature deviation are found in afternoon, and those of relative humidity and water vapor density are in the early morning. The detection deviations of temperature and relative humidity time series exhibit noticeable variations, and water vapor density is relatively stable. The precipitation, especially heavy rain, has significant impact on the accuracy of microwave radiometer detection.