Just browsing the web site of the Cerro Tololo observatory in Chile and felt sorry for the guys up there (NOT). November was a very bad month for them, with just 28 perfectly clear photometric nights, 1 "partly" cloudy night and poor *******s..the night of 14/15 Nov was mostly cloudy.
Can ya believe that?
Although some other months are slightly worse, if you browse the whole years weather stats it will make you even more depressed
http://www.ctio.noao.edu/site/phot/sky_conditions.php
Oh well back to cloudy Newcastle
Mike