Kendall Island
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kendall Island clear sky chart from 2005-11-05 to 2017-09-22.

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
29%
16311
10%
46758
6%
16264
33%
16264
16%
35315

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
21%
900
6%
2685
4%
895
24%
895
8%
2239
January16th to endNight
19%
960
8%
2736
4%
960
22%
960
9%
2326
February1st to 15thNight
28%
880
12%
2312
5%
876
33%
876
16%
1783
February16th to endNight
33%
759
11%
2021
5%
759
37%
759
17%
1539
March1st to 15thNight
30%
660
14%
2100
9%
660
35%
660
17%
1488
March16th to endNight
31%
576
16%
2046
12%
576
40%
576
16%
1400
April1st to 15thNight
35%
539
15%
1797
12%
539
42%
539
20%
1186
April16th to endNight
36%
540
17%
1566
8%
540
43%
540
24%
1048
May1st to 15thNight
26%
540
12%
1440
4%
540
30%
540
18%
1081
May16th to endNight
36%
563
7%
1480
4%
561
38%
561
22%
1068
June1st to 15thNight
39%
540
4%
1260
3%
540
40%
540
28%
905
June16th to endNight
45%
540
3%
1260
2%
540
46%
540
29%
889
July1st to 15thNight
47%
510
5%
1190
4%
510
48%
510
37%
796
July16th to endNight
50%
564
12%
1342
6%
531
51%
531
35%
875
August1st to 15thNight
48%
539
16%
1446
9%
536
50%
536
31%
951
August16th to endNight
45%
573
16%
1776
13%
573
50%
573
29%
1097
September1st to 15thNight
43%
540
13%
1800
12%
540
48%
540
23%
1150
September16th to endNight
33%
589
12%
1869
11%
589
37%
589
18%
1318
October1st to 15thNight
27%
660
14%
1980
7%
660
32%
660
16%
1456
October16th to endNight
21%
704
8%
2227
4%
704
25%
704
10%
1768
November1st to 15thNight
17%
875
7%
2451
3%
875
20%
875
10%
2014
November16th to endNight
16%
900
7%
2520
3%
900
19%
900
7%
2186
December1st to 15thNight
17%
900
5%
2574
2%
900
20%
900
7%
2218
December16th to endNight
17%
960
7%
2880
4%
960
20%
960
6%
2534

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%10%47%6%35%5%5%6%28%
48149
Night
14%11%5%8%6%35%5%45%27%
46912
Cloud CoverDay
16%10%47%6%35%5%5%6%29%
48159
Night
15%11%5%8%6%35%5%45%28%
46917
Cloud CoverDay
16%10%47%6%35%45%6%28%
48157
Night
15%11%5%8%6%35%5%45%27%
46917
TransparencyDay
56%411%19%7%
47821
Night
58%411%18%7%
46758
SeeingDay
23%10%30%21%10%3
6296
Night
22%9%29%26%10%1
16311

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
11%14%5%12%8%5%9%7%5%5%14%
1253
16th to endDay
11%13%7%11%8%6%8%7%6%5%12%
1488
February1st to 15thDay
8%12%48%7%6%8%10%5%5%22%
1551
16th to endDay
7%12%410%9%5%6%6%5%5%24%
1452
March1st to 15thDay
9%14%6%7%7%34445%31%
1862
16th to endDay
15%9%48%7%34445%31%
2177
April1st to 15thDay
11%11%46%5%24437%37%
2151
16th to endDay
17%10%35%424435%37%
2390
May1st to 15thDay
19%11%46%6%3445%5%27%
2511
16th to endDay
21%6%35%5%245%5%6%32%
2632
June1st to 15thDay
20%6%35%6%35%5%5%7%31%
2700
16th to endDay
18%6%36%5%46%6%5%7%29%
2700
July1st to 15thDay
16%6%26%435%5%5%7%37%
2700
16th to endDay
15%6%24435%46%8%38%
2731
August1st to 15thDay
12%5%25%5%35%5%7%8%37%
2504
16th to endDay
15%6%26%6%2446%6%38%
2426
September1st to 15thDay
19%7%36%423446%35%
2160
16th to endDay
24%10%25%433335%32%
1890
October1st to 15thDay
19%17%5%7%5%34345%22%
1650
16th to endDay
22%23%5%6%5%24225%18%
1644
November1st to 15thDay
21%18%6%9%6%3333318%
1407
16th to endDay
16%18%7%14%9%3444311%
1440
December1st to 15thDay
11%16%8%14%9%6%7%7%5%38%
1386
16th to endDay
15%18%10%10%9%46%5%46%8%
1344
January1st to 15thNight
10%14%6%13%8%5%9%7%6%313%
2685
16th to endNight
10%13%7%13%9%5%8%8%5%412%
2736
February1st to 15thNight
8%11%5%7%6%6%10%8%5%6%24%
2309
16th to endNight
7%13%5%9%8%46%7%46%25%
2021
March1st to 15thNight
11%12%5%7%6%34445%34%
2087
16th to endNight
15%11%5%6%5%34345%33%
2046
April1st to 15thNight
12%11%46%5%23445%39%
1797
16th to endNight
15%8%35%5%34346%39%
1566
May1st to 15thNight
20%10%46%435%445%31%
1440
16th to endNight
20%8%245%35%5%5%7%32%
1478
June1st to 15thNight
19%6%34423447%38%
1260
16th to endNight
15%5%245%346%6%8%38%
1260
July1st to 15thNight
11%5%35%32446%9%43%
1260
16th to endNight
13%5%24324448%46%
1435
August1st to 15thNight
10%5%35%4345%5%7%44%
1455
16th to endNight
15%6%2432335%7%46%
1776
September1st to 15thNight
15%7%25%42445%7%40%
1800
16th to endNight
20%8%35%5%23345%35%
1869
October1st to 15thNight
20%12%45%5%33336%29%
1980
16th to endNight
21%18%47%6%34345%21%
2227
November1st to 15thNight
19%20%5%8%6%25%33320%
2451
16th to endNight
18%15%7%14%9%5%5%33314%
2520
December1st to 15thNight
11%12%7%13%12%5%8%7%4412%
2574
16th to endNight
15%18%7%14%11%5%5%44310%
2880

Percentage Cloud Cover SW (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
11%14%5%12%8%49%7%5%414%
1253
16th to endDay
11%14%6%11%9%6%8%8%7%412%
1488
February1st to 15thDay
7%12%5%8%6%6%8%10%5%5%22%
1551
16th to endDay
7%12%5%10%9%47%5%5%5%25%
1452
March1st to 15thDay
10%14%6%7%7%3445%5%31%
1872
16th to endDay
15%10%48%6%44445%31%
2177
April1st to 15thDay
11%11%46%5%24347%37%
2151
16th to endDay
17%9%35%5%24435%37%
2390
May1st to 15thDay
19%11%47%6%3445%5%27%
2511
16th to endDay
22%6%35%5%245%5%6%33%
2632
June1st to 15thDay
21%6%245%35%5%5%8%30%
2700
16th to endDay
19%6%35%6%35%6%6%7%29%
2700
July1st to 15thDay
17%5%35%435%45%7%37%
2700
16th to endDay
16%6%25%43446%8%39%
2731
August1st to 15thDay
12%5%25%5%445%6%8%38%
2504
16th to endDay
15%5%26%5%3445%6%39%
2426
September1st to 15thDay
19%7%35%5%2445%6%35%
2160
16th to endDay
24%10%25%43333432%
1890
October1st to 15thDay
20%18%47%5%24345%22%
1650
16th to endDay
23%23%6%5%5%23325%18%
1644
November1st to 15thDay
21%18%7%8%6%2433418%
1407
16th to endDay
16%19%7%15%9%3443410%
1440
December1st to 15thDay
11%15%9%14%9%6%8%6%5%38%
1386
16th to endDay
17%16%10%10%9%46%5%46%8%
1344
January1st to 15thNight
10%14%6%12%8%5%9%7%6%413%
2685
16th to endNight
10%14%7%12%9%5%8%9%5%412%
2736
February1st to 15thNight
8%11%5%6%6%6%10%8%5%5%23%
2302
16th to endNight
7%13%5%9%8%47%7%45%25%
2021
March1st to 15thNight
12%11%5%7%6%345%35%34%
2100
16th to endNight
16%10%5%6%5%33445%34%
2046
April1st to 15thNight
12%11%36%5%2335%5%39%
1797
16th to endNight
15%8%36%5%25%346%39%
1566
May1st to 15thNight
20%10%47%5%24345%31%
1439
16th to endNight
20%7%245%25%45%7%32%
1478
June1st to 15thNight
20%6%245%23347%38%
1260
16th to endNight
15%4245%345%6%8%39%
1260
July1st to 15thNight
11%5%2432446%9%43%
1260
16th to endNight
14%5%13414348%47%
1435
August1st to 15thNight
10%5%25%4345%6%6%44%
1455
16th to endNight
15%6%2332335%6%46%
1776
September1st to 15thNight
16%7%2443345%7%40%
1800
16th to endNight
21%8%35%424345%35%
1869
October1st to 15thNight
20%13%45%5%23346%30%
1980
16th to endNight
22%19%37%5%34345%21%
2227
November1st to 15thNight
19%20%6%8%6%2433320%
2451
16th to endNight
18%15%8%13%9%4433314%
2520
December1st to 15thNight
11%12%7%13%12%5%8%6%4412%
2574
16th to endNight
15%17%8%13%11%5%5%44310%
2880

Percentage Cloud Cover SE (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
12%14%5%12%8%39%7%5%414%
1253
16th to endDay
11%14%6%10%9%6%8%7%7%412%
1488
February1st to 15thDay
7%12%5%8%6%5%9%10%5%5%22%
1551
16th to endDay
7%12%5%11%9%46%5%6%5%24%
1452
March1st to 15thDay
10%14%5%8%6%35%45%5%30%
1872
16th to endDay
15%10%48%6%44446%30%
2175
April1st to 15thDay
11%11%46%6%23447%37%
2151
16th to endDay
17%9%35%4335%45%37%
2390
May1st to 15thDay
19%12%48%434446%27%
2511
16th to endDay
22%6%35%5%2445%6%32%
2632
June1st to 15thDay
20%7%25%5%35%448%30%
2700
16th to endDay
19%6%35%6%36%5%6%7%29%
2700
July1st to 15thDay
17%5%35%5%35%45%6%37%
2700
16th to endDay
16%5%25%435%46%8%38%
2731
August1st to 15thDay
12%5%25%5%45%5%6%8%37%
2504
16th to endDay
15%7%25%5%3445%7%38%
2426
September1st to 15thDay
20%7%35%5%2445%6%35%
2160
16th to endDay
26%9%34423345%31%
1890
October1st to 15thDay
19%18%5%6%5%33346%22%
1650
16th to endDay
23%24%46%5%2423418%
1644
November1st to 15thDay
22%17%7%8%7%2423418%
1407
16th to endDay
17%18%7%15%9%3443311%
1440
December1st to 15thDay
12%15%8%14%9%5%8%7%5%38%
1386
16th to endDay
16%17%9%10%8%5%6%45%6%9%
1344
January1st to 15thNight
10%14%6%11%9%6%9%6%6%313%
2685
16th to endNight
10%14%7%12%8%5%8%9%5%412%
2736
February1st to 15thNight
8%11%47%7%6%10%8%5%5%23%
2302
16th to endNight
7%13%5%10%9%37%7%45%25%
2021
March1st to 15thNight
12%10%5%8%6%345%36%33%
2100
16th to endNight
15%11%5%6%5%33345%34%
2046
April1st to 15thNight
12%11%47%424345%39%
1797
16th to endNight
15%8%36%5%24445%40%
1566
May1st to 15thNight
21%9%46%5%24445%31%
1439
16th to endNight
20%7%34435%45%7%32%
1478
June1st to 15thNight
20%6%33423447%37%
1260
16th to endNight
14%5%25%4246%6%7%39%
1260
July1st to 15thNight
11%5%25%43445%9%43%
1260
16th to endNight
14%5%24423239%47%
1435
August1st to 15thNight
10%5%26%5%3445%7%43%
1455
16th to endNight
15%6%2332235%7%45%
1776
September1st to 15thNight
16%7%24423448%40%
1800
16th to endNight
22%8%35%424335%35%
1869
October1st to 15thNight
20%12%46%5%23346%29%
1980
16th to endNight
22%18%36%6%34345%21%
2227
November1st to 15thNight
19%19%6%8%6%3333420%
2451
16th to endNight
18%15%7%12%10%5%433314%
2520
December1st to 15thNight
11%12%7%12%12%5%7%7%4412%
2574
16th to endNight
15%17%7%14%10%46%5%3310%
2880

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
70%39%13%2
1254
16th to endDay
71%47%12%5%
1488
February1st to 15thDay
60%310%17%7%
1552
16th to endDay
59%211%19%5%
1452
March1st to 15thDay
55%411%17%8%1
1872
16th to endDay
55%311%17%8%2
2177
April1st to 15thDay
47%49%22%13%3
2151
16th to endDay
49%38%23%12%1
2390
May1st to 15thDay
57%49%21%7%
2511
16th to endDay
52%5%11%19%10%
2636
June1st to 15thDay
52%5%9%21%10%
2700
16th to endDay
52%6%14%19%6%
2700
July1st to 15thDay
44%6%12%28%7%
2541
16th to endDay
43%6%15%25%8%
2561
August1st to 15thDay
42%8%17%25%6%
2489
16th to endDay
44%5%15%25%7%
2426
September1st to 15thDay
48%5%14%25%6%
2160
16th to endDay
55%5%15%20%3
1890
October1st to 15thDay
63%312%15%4
1650
16th to endDay
70%311%12%1
1644
November1st to 15thDay
70%311%9%3
1407
16th to endDay
76%48%7%3
1440
December1st to 15thDay
77%48%7%1
1386
16th to endDay
76%27%8%4
1344
January1st to 15thNight
71%38%14%2
2685
16th to endNight
72%46%12%3
2736
February1st to 15thNight
59%311%17%7%
2312
16th to endNight
57%412%20%4
2021
March1st to 15thNight
52%413%16%11%1
2100
16th to endNight
53%211%19%8%4
2046
April1st to 15thNight
46%39%22%15%1
1797
16th to endNight
45%39%23%15%2
1566
May1st to 15thNight
55%48%19%11%
1440
16th to endNight
50%412%18%11%2
1480
June1st to 15thNight
46%410%20%16%
1260
16th to endNight
42%5%15%25%9%
1260
July1st to 15thNight
34%6%15%31%11%
1190
16th to endNight
37%413%31%10%1
1342
August1st to 15thNight
39%5%13%29%10%1
1446
16th to endNight
38%418%28%9%
1776
September1st to 15thNight
43%415%27%8%
1800
16th to endNight
51%414%24%4
1869
October1st to 15thNight
56%314%21%4
1980
16th to endNight
65%412%15%2
2227
November1st to 15thNight
68%311%12%2
2451
16th to endNight
75%38%8%2
2520
December1st to 15thNight
73%5%10%8%2
2574
16th to endNight
78%36%9%2
2880

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
13%12%48%23%2
90
16th to endDay
27%9%28%27%6%2
96
February1st to 15thDay
28%12%37%17%21
90
16th to endDay
25%19%34%13%32
81
March1st to 15thDay
15%10%41%25%43
90
16th to endDay
19%14%33%18%11%3
161
April1st to 15thDay
17%10%28%31%11%1
270
16th to endDay
25%9%32%21%9%1
423
May1st to 15thDay
28%15%30%17%6%2
468
16th to endDay
28%11%29%18%9%2
517
June1st to 15thDay
26%11%31%19%8%3
495
16th to endDay
24%9%28%20%11%5%
495
July1st to 15thDay
19%10%29%25%12%3
475
16th to endDay
18%8%26%23%15%6%
515
August1st to 15thDay
15%6%28%26%17%4
493
16th to endDay
22%7%28%24%15%1
466
September1st to 15thDay
23%7%29%25%11%2
315
16th to endDay
36%12%28%16%4
204
October1st to 15thDay
33%10%25%21%5%4
90
16th to endDay
42%6%38%11%1
96
November1st to 15thDay
40%6%34%12%6%
90
16th to endDay
35%13%28%14%7%
90
December1st to 15thDay
20%10%42%24%12
90
16th to endDay
22%12%41%16%33
96
January1st to 15thNight
19%13%34%23%8%1
900
16th to endNight
18%11%37%25%7%
960
February1st to 15thNight
15%10%34%27%9%1
880
16th to endNight
14%10%30%28%11%3
759
March1st to 15thNight
18%13%30%25%11%1
660
16th to endNight
22%9%28%24%9%5%
576
April1st to 15thNight
18%11%27%32%9%
539
16th to endNight
20%8%29%32%8%1
540
May1st to 15thNight
27%9%31%23%6%1
540
16th to endNight
25%6%27%29%11%
563
June1st to 15thNight
24%5%26%27%13%1
540
16th to endNight
18%6%23%35%15%1
540
July1st to 15thNight
13%6%30%31%16%2
510
16th to endNight
17%323%30%21%3
564
August1st to 15thNight
13%5%26%27%24%2
539
16th to endNight
20%426%29%17%1
573
September1st to 15thNight
22%6%24%30%14%1
540
16th to endNight
28%6%27%25%9%1
589
October1st to 15thNight
30%10%26%25%7%
660
16th to endNight
35%8%27%19%8%1
704
November1st to 15thNight
31%13%28%19%5%1
875
16th to endNight
28%12%29%23%41
900
December1st to 15thNight
18%10%36%25%8%1
900
16th to endNight
25%10%30%22%9%2
960
Page generated at 2017-09-23 06:43:45. Version ac04

Copyright 2017 A. Danko


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