AVAILABLE ALL-SKY DATA IN 1988 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 278 273 186 64 0 0 0 17 196 271 359 277 35 MUONIO 219 108 3 0 0 0 0 0 0 110 0 98 10 IVALO 0 0 0 0 0 0 0 0 0 0 0 0 0 KEVO 208 103 95 22 0 0 0 11 76 164 209 219 18 HANKASALMI 0 0 0 0 0 0 0 0 0 0 0 0 0 KILPISJARVI 387 226 190 27 0 0 0 49 182 256 270 329 40 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 92 112 39 0 0 0 0 0 0 0 90 106 7 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