AVAILABLE ALL-SKY DATA IN 1991 observation hours per month STATION JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC films (*) OULU 0 0 0 0 0 0 0 0 0 0 0 0 0 SODANKYLA 347 303 251 63 0 0 0 49 182 279 159 258 35 MUONIO 202 110 165 25 0 0 0 0 26 0 0 111 12 IVALO 0 0 0 0 0 0 0 0 0 0 0 0 0 KEVO 0 0 0 0 0 0 0 4 122 146 135 233 10 HANKASALMI 0 0 0 0 0 0 0 0 0 0 0 0 0 KILPISJARVI 224 265 180 83 0 0 0 42 178 218 193 162 28 KIRUNA 0 0 0 0 0 0 0 0 0 0 0 0 0 TROMSO 0 0 0 0 0 0 0 0 0 0 0 0 0 HORNSUND 0 0 0 0 0 0 0 0 0 0 0 0 0 ANDOYA 0 0 0 0 0 0 0 0 0 0 0 0 0 GEORG FORSTER 0 0 0 0 0 0 0 0 0 0 0 0 0 (*) analyzed films per year