Using Moderate Resolution Imaging Spectroradiometer (MODIS) Terra Level 3 data covering complete eights years from July 2000 to June 2008, and Aqua Level 3 data covering complete six years from July 2002 to June 2008 we studied regional and temporal properties of the Aerosol Optical Thickness (AOT) and Cloud Fraction. These include (1) maps of temporal correlations of the monthly AOT derived with various weighting schemes against the science quality pixel counts and cloud fraction, which could provide clues to aerosol-cloud interaction, (2) maps of linear trends and climatology of the monthly AOT, pixel counts and cloud fraction, which characterize temporal and spatial sampling. We investigated sensitivity of our results to possible instrument and platform biases that can lead to a better assessment of diurnal and seasonal cycles of aerosol and cloud interactions.