AVAILABLE ALL-SKY DATA IN 1990 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 410 172 187 78 0 0 0 7 208 327 327 467 40 MUONIO 87 129 137 60 0 0 0 11 171 64 0 148 15 IVALO 0 0 0 0 0 0 0 0 0 0 0 0 0 KEVO 120 93 154 61 0 0 0 0 133 117 162 163 19 HANKASALMI 0 0 0 0 0 0 0 0 0 0 0 0 0 KILPISJARVI 235 144 143 71 0 0 0 9 172 180 250 210 32 KIRUNA 0 0 21 0 0 0 0 0 0 0 0 0 1 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 0 323 187 372 383 253 92 0 0 31 (*) analyzed films per year