Future Satellite Imagers are expected to improve current ones on environmental and meteorological applications. In this study, an automatic classification scheme using radiance measurements with a clustering method is applied in an attempt to compare the capability on cloud classification by different sensors: AVHRR/3, the current GOES-12 Imager, SEVIRI, VIIRS, and ABI. The MODIS cloud mask is used as the initial classification. The results are analyzed with the help of true color and RGB composite images as well as other information about surface and cloud types. Results indicate that the future sensors (ABI and VIIRS) provide much better overall cloud classification capabilities than their corresponding current sensors (the current GOES-12 Imager and AVHRR/3) from the two chosen demonstration cases. However, for a specific class, it is not always true that more spectral bands result in better classification. In order to optimally use the spectral information, it is necessary to determine which bands are more sensitive for a specific class. Spatial resolution and the signal-to-noise ratio (SNR) of satellite sensors can significantly affect the classification. The 2.13µm band could be useful for thin low cloud detection and the 3.7µm band is useful for fresh snow detection.