1995 Flagstaff Nighttime Cloudiness Summary Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Yr (nights) Photometric 0 6 3 6 2 15 11 8 6 15 5 3 80 Monthly Average: 6.7 Partial 4 3 5 6 6 4 6 5 8 7 4 8 66 Monthly Average: 5.5 Spectroscopic 3 5 6 2 7 5 8 2 7 4 9 8 66 Monthly Average: 5.5 Cloudy 24 14 17 16 16 6 6 16 9 5 12 12 153 Monthly Average: 12.8 -------------------------------------------------------------------------------- Clear Hours 19 81 61 74 38 119 100 65 108 196 83 92 1036 Monthly Average: 86.3 Clear+Dark Hours 5 45 40 36 29 71 68 46 52 88 29 30 539 Monthly Average: 44.9 Mean Consec 0 2.0 1.0 1.5 1.0 3.8 3.7 1.6 2.0 2.5 1.7 1.0 Monthly Average: 1.8 Max Consec 0 3 1 3 1 8 5 3 3 4 2 1 Monthly Average: 2.8 -------------------------------------------------------------------------------- Definitions: Photometric - cloudfree dusk-to-dawn. Partial - at least 3 consecutive cloudfree hours during the night. Spectroscopic - less than about 1 mag. extinction throughout the night. Cloudy - cloudy. Clear+Dark Hours = photometric hours with moon absent. Mean Consec = mean number of consecutive photometric nights during the month. Max Consec = maximum number of consecutive photometric nights during the month.