The tables below list fractions. The numerators of the fractions tell the number of stations which (according to keograms) were operating in Svalbard and the denominators tell the number of operating mainland stations (c.f. a map). In order to see which stations were operating, check keograms. Note that the fraction of e.g. Sep 08 tells the availability during the night between Sep 08 and Sep 09.
Cloudiness index is defined at MUO and KEV at every three hours: 0000 UT, 0300 UT, ..., and 2100UT. At KIL clouds are observed only during day time (at 0300 UT ..., 1800 UT). Cloudiness is characterized with an index which varies from 0 (clear) to 8 (cloudy, when clouds cannot be observed e.g. due to fog the index is 9). The values listed below are mean values of the dark time indices (observed at 0000 UT, 1500 UT, 1800 UT, 2100 UT at MUO and KEV, and at 1800 UT at KIL).
Guide lines for interpretation: The tables below may serve an explanation why the keogram of your interest is black or fuzzy (interpreting keograms). On the other hand, do not loose your hope if the index is 8, it is still possible that the sky has been clear and our cameras have seen activity during short periods between the cloud observing hours.