Air temperature measurement errors caused by solar radiation and ambient wind speed are well-know issues. However, realtime air temperature filtering models are essential for generating homogenous climate data by transforming one air temperature measurement system into another, and correcting in-situ air temperature errors especially for non aspirated radiation shield systems. This study was to investigate the air temperature errors caused in the commonly used radiation shields in the United States, including the ASOS, MMTS, Gill, CRS, ASP-ES, and NON-ASP-ES shields along with corresponding temperature sensors. The realtime air temperature filtering models developed for each air temperature system are capable of removing the solar radiation, ambient wind speed, and ground surface albedo effects on air temperature measurements taken at any weather station or experimental site.