2022 Flagstaff Nighttime Cloudiness Summary Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Yr (nights) Photometric 7 13 7 13 12 8 4 0 8 12 10 6 100 Monthly Average: 8.3 Partial 9 6 6 5 5 3 1 6 5 9 14 3 72 Monthly Average: 6.0 Spectroscopic 0 0 0 2 4 4 0 1 0 0 0 3 14 Monthly Average: 1.2 Cloudy 15 9 18 10 10 15 26 24 17 10 6 19 179 Monthly Average: 14.9 ------------------------------------------------------------------------------- Clear Hours 139 178 106 139 111 71 33 34 107 174 199 93 1384 Monthly Average: 115 Clear+Dark Hours 92 90 49 67 60 33 21 31 71 87 117 45 763 Monthly Average: 64 Mean Consec 1.2 1.9 1.8 2.6 1.5 2.0 2.0 0 2.0 2.0 1.6 1.2 Monthly Average: 1.7 Max Consec 2 3 3 4 2 4 3 0 5 5 3 2 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.