Akulivik
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Akulivik clear sky chart from 2005-11-05 to 2017-12-01.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
32%
15505
4%
47552
4%
15475
33%
15475
7%
40482

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
40%
930
8%
3043
7%
925
41%
925
7%
2519
January16th to endNight
47%
981
10%
3086
9%
981
49%
981
10%
2489
February1st to 15thNight
51%
869
7%
2631
7%
869
52%
869
10%
2131
February16th to endNight
48%
631
7%
2065
7%
631
49%
631
11%
1609
March1st to 15thNight
42%
720
9%
2178
7%
720
44%
720
10%
1739
March16th to endNight
42%
768
9%
2045
6%
768
44%
768
14%
1608
April1st to 15thNight
45%
574
10%
1652
8%
574
48%
574
14%
1257
April16th to endNight
35%
360
2%
1413
1%
360
35%
360
8%
1125
May1st to 15thNight
28%
360
0%
1136
0%
360
28%
360
9%
918
May16th to endNight
30%
375
0%
1016
0%
374
30%
374
12%
837
June1st to 15thNight
33%
360
0%
732
0%
360
33%
360
20%
597
June16th to endNight
42%
360
0%
720
0%
360
42%
360
23%
576
July1st to 15thNight
45%
340
0%
785
0%
340
45%
340
20%
610
July16th to endNight
41%
376
0%
951
0%
354
44%
354
17%
732
August1st to 15thNight
39%
359
0%
1217
0%
357
39%
357
11%
935
August16th to endNight
33%
427
3%
1553
3%
427
34%
427
8%
1222
September1st to 15thNight
22%
653
3%
1733
3%
653
22%
653
7%
1514
September16th to endNight
11%
717
3%
1984
1%
717
13%
717
4%
1833
October1st to 15thNight
17%
720
2%
2182
2%
720
17%
720
5%
1984
October16th to endNight
15%
768
3%
2688
3%
768
16%
768
3%
2418
November1st to 15thNight
17%
910
3%
2931
2%
910
17%
910
3%
2721
November16th to endNight
18%
1020
1%
3125
1%
1020
18%
1020
2%
2984
December1st to 15thNight
26%
935
3%
3242
3%
935
26%
935
3%
3009
December16th to endNight
29%
992
3%
3444
2%
992
30%
992
3%
3115

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
15%13%6%10%8%46%6%5%5%17%
48940
Night
12%14%7%12%10%5%7%6%6%5%10%
47656
TransparencyDay
65%6%11%14%3
48562
Night
70%7%8%10%3
47552
SeeingDay
21%12%12%22%20%11%
7525
Night
17%16%11%21%22%10%
15508

By Month

Percentage Cloud Cover NE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
5%8%5%10%15%9%10%9%11%5%8%
895
16th to endDay
49%5%10%12%8%11%10%14%7%4
1136
February1st to 15thDay
245%13%13%7%11%11%14%9%6%
1232
16th to endDay
27%411%11%6%11%12%14%6%11%
1408
March1st to 15thDay
5%10%5%10%9%6%11%12%14%6%7%
1772
16th to endDay
36%5%8%10%7%10%15%9%5%15%
2179
April1st to 15thDay
6%9%48%10%7%10%8%7%6%20%
2307
16th to endDay
10%10%5%11%13%7%10%6%5%5%14%
2547
May1st to 15thDay
16%13%6%13%8%44335%18%
2815
16th to endDay
12%13%8%13%7%35%45%6%18%
3096
June1st to 15thDay
13%14%6%8%6%35%446%25%
3227
16th to endDay
14%9%47%435%5%5%8%31%
3240
July1st to 15thDay
19%9%47%5%24346%31%
3123
16th to endDay
19%11%46%5%35%5%45%27%
3151
August1st to 15thDay
25%11%35%42346%6%25%
2734
16th to endDay
30%12%47%323345%20%
2648
September1st to 15thDay
29%16%5%9%6%2432415%
2215
16th to endDay
28%27%6%10%6%122228%
1974
October1st to 15thDay
27%26%6%9%7%333228%
1776
16th to endDay
22%23%10%12%6%2322211%
1536
November1st to 15thDay
15%21%13%17%9%343226%
1257
16th to endDay
11%18%9%22%15%5%5%3223
1163
December1st to 15thDay
6%11%10%16%18%6%9%6%45%5%
732
16th to endDay
7%12%7%12%14%8%10%12%5%25%
777
January1st to 15thNight
410%6%11%13%6%10%12%9%6%8%
3043
16th to endNight
37%6%11%10%5%13%13%14%6%5%
3086
February1st to 15thNight
35%5%10%12%8%12%13%13%7%6%
2628
16th to endNight
39%39%12%9%12%11%13%6%8%
2065
March1st to 15thNight
5%10%410%11%7%10%10%15%8%5%
2165
16th to endNight
49%411%10%5%10%11%10%8%14%
2045
April1st to 15thNight
8%9%47%7%6%11%8%7%9%19%
1652
16th to endNight
9%11%7%11%12%6%7%446%17%
1413
May1st to 15thNight
16%16%7%11%8%33335%20%
1136
16th to endNight
14%15%11%14%6%2125%5%19%
1014
June1st to 15thNight
14%14%7%11%333345%26%
732
16th to endNight
13%11%5%8%5%2446%6%30%
720
July1st to 15thNight
20%10%5%6%425%35%5%29%
834
16th to endNight
21%11%5%7%5%2435%427%
1017
August1st to 15thNight
25%10%36%5%23446%25%
1224
16th to endNight
30%14%46%323335%20%
1553
September1st to 15thNight
29%18%49%6%3333314%
1733
16th to endNight
29%27%5%9%6%222218%
1984
October1st to 15thNight
27%27%6%9%5%2323210%
2182
16th to endNight
22%25%10%11%6%233327%
2688
November1st to 15thNight
15%23%12%16%7%443336%
2931
16th to endNight
11%17%12%19%15%6%6%3222
3125
December1st to 15thNight
6%12%7%18%19%8%9%5%335%
3242
16th to endNight
7%13%8%16%14%7%10%9%5%33
3444

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
67%8%11%11%1
896
16th to endDay
63%8%7%12%8%
1136
February1st to 15thDay
58%9%12%15%3
1233
16th to endDay
57%8%11%15%7%
1408
March1st to 15thDay
61%7%10%14%5%
1782
16th to endDay
56%9%8%17%8%
2179
April1st to 15thDay
59%5%8%18%6%
2307
16th to endDay
72%5%7%12%2
2547
May1st to 15thDay
70%29%14%3
2815
16th to endDay
68%311%13%3
3100
June1st to 15thDay
60%413%18%2
3227
16th to endDay
49%6%16%25%2
3240
July1st to 15thDay
51%5%16%23%3
2943
16th to endDay
57%6%16%16%2
2954
August1st to 15thDay
57%9%19%11%1
2717
16th to endDay
66%5%14%11%1
2648
September1st to 15thDay
74%5%9%10%
2215
16th to endDay
84%36%4
1974
October1st to 15thDay
82%46%41
1776
16th to endDay
79%46%8%
1536
November1st to 15thDay
83%7%34
1257
16th to endDay
85%6%34
1163
December1st to 15thDay
76%8%8%41
732
16th to endDay
75%8%8%7%
777
January1st to 15thNight
64%11%10%13%1
3043
16th to endNight
61%9%10%11%6%
3086
February1st to 15thNight
61%9%8%15%3
2631
16th to endNight
60%7%11%13%6%
2065
March1st to 15thNight
63%5%8%16%5%
2178
16th to endNight
57%8%10%15%8%
2045
April1st to 15thNight
56%6%9%21%6%
1652
16th to endNight
67%48%15%4
1413
May1st to 15thNight
68%38%15%4
1136
16th to endNight
68%29%14%4
1016
June1st to 15thNight
59%310%21%4
732
16th to endNight
55%412%24%3
720
July1st to 15thNight
54%5%14%21%3
785
16th to endNight
58%419%14%3
951
August1st to 15thNight
60%6%16%14%2
1217
16th to endNight
65%5%15%11%1
1553
September1st to 15thNight
74%5%8%9%1
1733
16th to endNight
83%45%5%
1984
October1st to 15thNight
81%45%6%2
2182
16th to endNight
80%5%6%6%
2688
November1st to 15thNight
81%7%45%1
2931
16th to endNight
86%7%33
3125
December1st to 15thNight
82%7%431
3242
16th to endNight
78%7%6%6%
3444

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
11%113%40%26%6%
60
16th to endDay
10%110%32%28%15%
64
February1st to 15thDay
311%46%38%
60
16th to endDay
312%26%37%19%
78
March1st to 15thDay
11%11%18%22%21%16%
198
16th to endDay
5%13%13%19%26%21%
288
April1st to 15thDay
10%11%8%26%21%22%
270
16th to endDay
10%13%18%22%19%16%
297
May1st to 15thDay
20%15%15%22%15%10%
592
16th to endDay
15%15%12%21%23%10%
705
June1st to 15thDay
18%15%10%23%19%12%
675
16th to endDay
17%15%11%25%21%8%
675
July1st to 15thDay
23%10%11%24%18%11%
645
16th to endDay
25%14%7%22%22%6%
703
August1st to 15thDay
27%9%8%19%24%11%
527
16th to endDay
41%7%8%13%19%9%
352
September1st to 15thDay
36%9%13%22%12%6%
315
16th to endDay
41%12%15%18%10%2
314
October1st to 15thDay
36%11%18%21%9%1
307
16th to endDay
22%6%18%27%19%5%
96
November1st to 15thDay
8%421%31%22%12%
90
16th to endDay
22%415%15%25%16%
90
December1st to 15thDay
36%30%33%26%
60
16th to endDay
3321%21%28%21%
64
January1st to 15thNight
7%18%10%23%23%15%
930
16th to endNight
6%17%7%21%30%16%
981
February1st to 15thNight
317%5%20%33%20%
872
16th to endNight
5%15%8%21%29%19%
631
March1st to 15thNight
8%18%13%23%22%13%
720
16th to endNight
6%19%12%20%28%13%
768
April1st to 15thNight
10%18%11%24%21%14%
574
16th to endNight
12%20%12%23%21%9%
360
May1st to 15thNight
20%18%13%27%13%7%
360
16th to endNight
16%17%9%25%25%5%
375
June1st to 15thNight
18%18%12%23%20%5%
360
16th to endNight
16%16%11%26%22%5%
360
July1st to 15thNight
25%12%5%26%22%6%
340
16th to endNight
23%18%8%24%21%3
376
August1st to 15thNight
31%11%6%17%27%6%
359
16th to endNight
35%11%9%19%19%4
427
September1st to 15thNight
39%13%12%18%12%3
653
16th to endNight
40%15%17%13%9%2
717
October1st to 15thNight
40%13%13%21%10%
720
16th to endNight
29%14%15%20%14%5%
768
November1st to 15thNight
20%16%16%23%16%5%
910
16th to endNight
14%18%14%21%23%8%
1020
December1st to 15thNight
8%17%12%21%26%13%
935
16th to endNight
10%18%10%23%23%12%
992
Page generated at 2017-12-02 09:14:23. Version ac04

Copyright 2017 A. Danko


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