Mean monthly frequency (%) of clear and overcast sky conditions (midnight to midnight observations).
71° 17'N / 156° 46' W
30.8 ft. above sea level
midnight - midnight
sunrise - sunset
Analyses are based on hourly observations for the years 1971 - 1998.
Clear skies are defined as 0 to 0.30 coverage, partly cloudy 0.40 to 0.70, and cloudy skies 0.80 to 1.00.
Mean monthly frequency (%) of clear, partly cloudy, and cloudy sky condition and mean cloudiness (fraction of sky coverage).
| Sky Condition |
Jan
|
Feb
|
Mar
|
Apr
|
May
|
Jun
|
Jul
|
Aug
|
Sep
|
Oct
|
Nov
|
Dec
|
| Clear |
48
|
47
|
51
|
43
|
17
|
15
|
18
|
7
|
5
|
12
|
37
|
46
|
| Partly Cloudy |
13
|
12
|
12
|
10
|
7
|
10
|
12
|
7
|
5
|
8
|
13
|
11
|
| Cloudy |
39
|
41
|
37
|
47
|
76
|
75
|
70
|
86
|
90
|
80
|
50
|
43
|
|
Mean Cloudiness
|
0.48
|
0.49
|
0.45
|
0.54
|
0.80
|
0.80
|
0.77
|
0.89
|
0.93
|
0.84
|
0.59
|
0.50
|