http://neo.sci.gsfc.nasa.gov/view.ph...ate=2015-04-01 is a 1 snapshot per day example of historical cloud cover data available.
an archive of all daily snapshots since 2000 is available in bulk here:
http://neo.sci.gsfc.nasa.gov/about/ftp.php
the folder to get is MODAL2_D_CLD_FR
I used Filezilla as ftp-client to download the big folder because the web-download did not complete as is common with such big packages.
Unfortunately, neither my slideshow-making approach (Aperture 3.5 and iPhoto) nor my movie editing approach (FinalCut Pro 7) would yield a usable and sharable file.
But that is due to the limitations of those programs and my not willing to spend even more time working around those issues.
But the visual data IS there and could be converted into something usable by someone else, I'm sure.
There are also .csv files available of the same time period. I haven't had a look at those, though, because I assumed it would take more time for me to figure out how to use that numeric data and find out how to combine it to make it answer our question.