This paper describes a methodology to correct satellite-derived irradiances over complex terrain for models that use the visible satellite channel as main input for cloud index determination. Complex terrain is characterized by high reflectance surface and or the juxtaposition of high and low reflectance surfaces (e.g., desert plains and forested ridges). The correction consists of (1) climate dependent post-model clear sky calibration and (2) singularity identification and removal. (C) 2004 Elsevier Ltd. All rights reserved.