Aupaluk
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Aupaluk 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
37%
15191
6%
47637
5%
15159
39%
15159
12%
37272

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
42%
930
8%
2986
6%
925
44%
925
10%
2389
January16th to endNight
48%
966
14%
3046
11%
966
51%
966
17%
2244
February1st to 15thNight
48%
712
7%
2512
7%
709
51%
709
11%
1912
February16th to endNight
48%
631
6%
2121
7%
631
49%
631
12%
1641
March1st to 15thNight
47%
716
10%
2151
6%
716
50%
716
17%
1606
March16th to endNight
38%
768
12%
2031
7%
768
41%
768
18%
1576
April1st to 15thNight
34%
581
8%
1659
7%
581
36%
581
15%
1279
April16th to endNight
35%
417
7%
1434
7%
417
37%
417
14%
1060
May1st to 15thNight
34%
360
0%
1260
0%
360
34%
360
10%
994
May16th to endNight
31%
374
0%
1000
0%
374
31%
374
12%
819
June1st to 15thNight
37%
360
0%
900
0%
360
37%
360
16%
717
June16th to endNight
40%
360
0%
900
0%
360
40%
360
16%
732
July1st to 15thNight
37%
340
0%
850
0%
340
37%
340
14%
689
July16th to endNight
42%
376
0%
1037
0%
354
43%
354
13%
815
August1st to 15thNight
39%
359
0%
1255
0%
357
39%
357
9%
979
August16th to endNight
44%
469
4%
1615
5%
469
46%
469
12%
1242
September1st to 15thNight
34%
607
8%
1717
5%
607
36%
607
13%
1353
September16th to endNight
22%
717
4%
1980
1%
717
24%
717
9%
1700
October1st to 15thNight
24%
720
6%
2239
3%
720
27%
720
8%
1882
October16th to endNight
23%
790
5%
2592
3%
790
26%
790
7%
2206
November1st to 15thNight
32%
805
7%
2853
5%
805
36%
805
11%
2219
November16th to endNight
27%
906
7%
3162
4%
906
31%
906
10%
2488
December1st to 15thNight
37%
935
5%
3073
3%
935
39%
935
13%
2318
December16th to endNight
44%
992
9%
3264
7%
992
46%
992
14%
2412

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
16%12%5%9%7%45%5%5%6%21%
48848
Night
13%12%5%9%8%46%5%5%6%21%
47749
TransparencyDay
62%6%13%14%3
48478
Night
61%6%13%14%3
47637
SeeingDay
24%418%24%19%8%
7655
Night
19%420%29%20%5%
15196

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
8%10%6%10%11%8%8%6%6%419%
949
16th to endDay
7%11%5%9%9%5%6%6%6%6%26%
1177
February1st to 15thDay
29%6%9%9%6%10%8%5%7%22%
1349
16th to endDay
6%8%411%12%6%9%8%6%6%20%
1351
March1st to 15thDay
5%10%5%9%9%5%7%8%6%7%25%
1799
16th to endDay
7%11%5%9%11%5%9%6%6%6%21%
2190
April1st to 15thDay
8%14%6%10%9%46%5%5%6%22%
2290
16th to endDay
12%11%5%9%10%45%45%7%23%
2536
May1st to 15thDay
14%13%5%11%8%45%5%36%19%
2691
16th to endDay
13%14%8%10%6%34446%21%
3113
June1st to 15thDay
17%14%6%8%6%34446%21%
3060
16th to endDay
24%10%47%6%35%445%22%
3060
July1st to 15thDay
25%10%46%5%3445%6%22%
3060
16th to endDay
19%10%48%7%45%5%45%23%
3058
August1st to 15thDay
23%9%37%5%35%5%5%7%23%
2695
16th to endDay
23%11%47%6%3345%6%23%
2575
September1st to 15thDay
24%11%5%8%6%34445%19%
2241
16th to endDay
24%19%5%9%6%2333317%
1980
October1st to 15thDay
27%16%5%7%7%1335%5%15%
1719
16th to endDay
21%19%5%8%6%2434417%
1632
November1st to 15thDay
15%16%7%9%8%3435%421%
1335
16th to endDay
11%17%6%11%7%45%45%421%
1127
December1st to 15thDay
7%10%6%10%10%6%6%46%6%24%
901
16th to endDay
7%7%5%11%10%5%6%5%6%7%25%
960
January1st to 15thNight
8%11%6%10%10%7%7%6%5%420%
2986
16th to endNight
6%10%5%9%9%5%7%5%6%6%27%
3046
February1st to 15thNight
311%6%10%10%6%8%9%5%6%20%
2510
16th to endNight
7%8%5%11%10%5%9%9%7%7%17%
2121
March1st to 15thNight
6%9%6%9%7%5%7%7%7%7%25%
2138
16th to endNight
7%10%5%10%10%47%6%6%8%21%
2031
April1st to 15thNight
10%13%6%11%8%44346%25%
1659
16th to endNight
10%10%7%10%9%45%45%5%25%
1434
May1st to 15thNight
18%13%6%10%7%4435%5%19%
1260
16th to endNight
16%14%10%9%6%34336%20%
998
June1st to 15thNight
19%12%6%8%6%35%35%7%21%
900
16th to endNight
22%13%47%5%35%5%6%5%22%
900
July1st to 15thNight
25%12%47%5%3445%7%19%
900
16th to endNight
24%10%45%5%27%5%5%7%20%
1108
August1st to 15thNight
23%10%48%6%3445%7%20%
1263
16th to endNight
23%9%37%6%3445%6%25%
1615
September1st to 15thNight
20%11%5%8%6%35%45%6%22%
1717
16th to endNight
24%17%49%6%34435%16%
1980
October1st to 15thNight
24%18%47%7%3443416%
2239
16th to endNight
23%19%7%7%5%3433416%
2592
November1st to 15thNight
15%14%7%10%6%44445%22%
2853
16th to endNight
14%14%6%10%8%45%446%20%
3162
December1st to 15thNight
8%10%5%11%8%5%6%5%6%7%23%
3073
16th to endNight
7%9%5%9%9%5%7%6%5%7%25%
3264

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
66%5%11%13%3
950
16th to endDay
56%311%17%10%
1177
February1st to 15thDay
57%6%13%16%5%
1351
16th to endDay
59%7%12%12%7%
1351
March1st to 15thDay
53%8%12%18%7%
1809
16th to endDay
59%5%10%16%7%
2190
April1st to 15thDay
61%6%7%18%6%
2290
16th to endDay
59%5%11%17%4
2536
May1st to 15thDay
65%5%11%14%3
2691
16th to endDay
63%6%12%13%4
3117
June1st to 15thDay
62%5%13%15%2
3060
16th to endDay
61%6%14%15%1
3060
July1st to 15thDay
62%6%15%13%2
2881
16th to endDay
59%8%16%14%
2866
August1st to 15thDay
58%8%17%14%1
2679
16th to endDay
60%7%17%11%2
2575
September1st to 15thDay
66%7%12%12%1
2241
16th to endDay
73%49%11%1
1980
October1st to 15thDay
70%5%10%10%2
1719
16th to endDay
70%6%11%10%1
1632
November1st to 15thDay
65%5%14%11%3
1335
16th to endDay
63%7%13%14%
1127
December1st to 15thDay
58%8%19%10%2
901
16th to endDay
56%7%15%18%2
960
January1st to 15thNight
64%6%12%14%2
2986
16th to endNight
54%6%12%16%9%
3046
February1st to 15thNight
60%6%14%11%5%
2512
16th to endNight
60%7%15%11%5%
2121
March1st to 15thNight
54%7%14%17%6%
2151
16th to endNight
58%411%18%6%
2031
April1st to 15thNight
60%47%16%10%
1659
16th to endNight
58%410%18%7%
1434
May1st to 15thNight
65%49%16%4
1260
16th to endNight
65%5%12%13%3
1000
June1st to 15thNight
61%5%15%15%3
900
16th to endNight
63%412%16%2
900
July1st to 15thNight
63%5%14%14%2
850
16th to endNight
59%7%15%15%1
1037
August1st to 15thNight
62%8%14%13%1
1255
16th to endNight
58%8%15%15%2
1615
September1st to 15thNight
61%6%12%17%2
1717
16th to endNight
72%5%10%10%1
1980
October1st to 15thNight
71%410%10%2
2239
16th to endNight
72%5%11%9%1
2592
November1st to 15thNight
62%5%15%13%2
2853
16th to endNight
64%5%14%13%1
3162
December1st to 15thNight
58%6%22%10%2
3073
16th to endNight
56%6%17%16%2
3264

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
8%335%11%31%10%
60
16th to endDay
18%15%29%29%6%
64
February1st to 15thDay
3315%25%25%28%
60
16th to endDay
8%112%34%32%10%
137
March1st to 15thDay
10%6%22%33%19%7%
270
16th to endDay
14%221%24%21%14%
288
April1st to 15thDay
12%5%16%29%23%11%
270
16th to endDay
22%424%25%15%7%
333
May1st to 15thDay
20%316%26%21%11%
468
16th to endDay
19%5%21%22%22%7%
697
June1st to 15thDay
27%215%23%21%8%
675
16th to endDay
31%417%23%14%8%
675
July1st to 15thDay
33%213%23%18%7%
645
16th to endDay
23%5%15%24%25%5%
703
August1st to 15thDay
30%113%18%22%13%
488
16th to endDay
28%313%24%19%11%
332
September1st to 15thDay
30%5%16%22%18%6%
315
16th to endDay
34%6%27%19%10%3
314
October1st to 15thDay
33%10%21%24%6%3
278
16th to endDay
32%6%21%19%16%3
279
November1st to 15thDay
14%417%30%27%5%
90
16th to endDay
14%8%26%26%18%4
90
December1st to 15thDay
16%110%41%18%11%
60
16th to endDay
6%7%23%32%23%6%
64
January1st to 15thNight
12%419%29%25%8%
930
16th to endNight
10%319%36%22%8%
966
February1st to 15thNight
7%417%29%30%10%
712
16th to endNight
10%314%30%30%10%
631
March1st to 15thNight
10%421%33%23%6%
720
16th to endNight
12%426%30%20%6%
768
April1st to 15thNight
16%423%29%22%5%
581
16th to endNight
15%227%35%15%3
417
May1st to 15thNight
25%320%26%20%3
360
16th to endNight
22%419%23%27%3
375
June1st to 15thNight
26%414%25%26%2
360
16th to endNight
28%316%29%19%3
360
July1st to 15thNight
33%215%23%22%3
340
16th to endNight
28%213%25%27%2
376
August1st to 15thNight
28%210%25%27%5%
359
16th to endNight
29%112%28%23%4
469
September1st to 15thNight
25%421%29%15%3
607
16th to endNight
33%8%24%20%11%2
717
October1st to 15thNight
33%7%20%24%10%2
720
16th to endNight
33%6%19%21%13%5%
790
November1st to 15thNight
23%422%29%16%4
805
16th to endNight
20%6%26%26%14%5%
906
December1st to 15thNight
13%424%32%20%4
935
16th to endNight
11%221%37%20%7%
992
Page generated at 2017-12-02 09:14:19. Version ac04

Copyright 2017 A. Danko


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