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 2019-06-19.

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%
18772
10%
53856
6%
18725
33%
18725
16%
40749

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%
1050
8%
3135
4%
1045
25%
1045
9%
2594
January16th to endNight
19%
1120
8%
3192
4%
1120
23%
1120
9%
2685
February1st to 15thNight
27%
1030
12%
2706
5%
1026
31%
1026
15%
2127
February16th to endNight
32%
884
11%
2354
4%
884
37%
884
16%
1790
March1st to 15thNight
30%
770
14%
2450
9%
770
35%
770
16%
1741
March16th to endNight
33%
672
17%
2388
13%
672
42%
672
17%
1604
April1st to 15thNight
35%
629
16%
2097
13%
629
44%
629
21%
1374
April16th to endNight
37%
624
16%
1809
9%
624
43%
624
24%
1216
May1st to 15thNight
27%
630
13%
1680
5%
630
33%
630
20%
1237
May16th to endNight
36%
659
8%
1734
5%
657
37%
657
23%
1226
June1st to 15thNight
38%
630
5%
1470
3%
630
40%
630
29%
1043
June16th to endNight
46%
597
3%
1393
2%
597
47%
597
29%
984
July1st to 15thNight
46%
555
7%
1295
4%
555
48%
555
38%
851
July16th to endNight
52%
612
12%
1463
6%
579
52%
579
35%
944
August1st to 15thNight
48%
575
16%
1542
9%
572
51%
572
31%
1014
August16th to endNight
44%
621
16%
1925
12%
621
49%
621
28%
1195
September1st to 15thNight
41%
585
14%
1950
12%
585
47%
585
23%
1250
September16th to endNight
31%
672
11%
2127
10%
672
34%
672
16%
1548
October1st to 15thNight
25%
780
13%
2340
6%
780
30%
780
15%
1736
October16th to endNight
19%
832
8%
2632
4%
832
24%
832
10%
2092
November1st to 15thNight
16%
1025
6%
2871
2%
1025
19%
1025
9%
2403
November16th to endNight
14%
1050
7%
2940
2%
1050
18%
1050
6%
2565
December1st to 15thNight
16%
1050
5%
3003
2%
1050
19%
1050
7%
2586
December16th to endNight
18%
1120
7%
3360
4%
1120
22%
1120
6%
2944

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%10%47%6%35%5%5%6%29%
54887
Night
14%11%48%6%45%5%45%27%
54010
Cloud CoverDay
16%10%47%6%35%45%6%29%
54897
Night
14%11%48%7%35%5%45%27%
54015
Cloud CoverDay
16%10%47%6%35%45%6%28%
54895
Night
14%11%48%7%35%5%45%27%
54015
TransparencyDay
55%411%19%7%
54559
Night
58%411%18%7%
53856
SeeingDay
23%11%31%21%9%2
8629
Night
21%9%30%26%10%1
18772

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
10%14%6%13%7%5%8%6%5%5%15%
1463
16th to endDay
10%12%7%11%8%6%8%7%6%6%13%
1736
February1st to 15thDay
8%12%48%8%6%8%9%5%5%21%
1817
16th to endDay
7%12%5%11%9%46%6%5%5%25%
1690
March1st to 15thDay
9%13%6%8%8%35%445%30%
2174
16th to endDay
14%10%48%7%34445%32%
2539
April1st to 15thDay
10%10%47%5%24437%37%
2511
16th to endDay
15%9%35%5%245%46%37%
2751
May1st to 15thDay
17%11%46%6%3435%6%28%
2931
16th to endDay
21%6%345%245%5%6%34%
3082
June1st to 15thDay
20%5%35%6%345%5%8%32%
3150
16th to endDay
19%6%35%5%46%6%5%7%29%
2975
July1st to 15thDay
15%5%25%4345%5%7%38%
2925
16th to endDay
14%6%245%35%45%8%38%
2961
August1st to 15thDay
12%5%25%5%35%5%6%8%38%
2661
16th to endDay
14%6%26%6%2445%7%38%
2629
September1st to 15thDay
18%8%35%423446%36%
2340
16th to endDay
26%10%36%42433429%
2148
October1st to 15thDay
21%17%5%7%5%24335%22%
1950
16th to endDay
22%23%6%6%423235%18%
1943
November1st to 15thDay
20%19%7%9%7%3333316%
1647
16th to endDay
16%18%7%16%10%3344310%
1680
December1st to 15thDay
10%15%8%14%10%6%6%6%5%410%
1616
16th to endDay
14%17%9%11%10%46%5%5%5%9%
1568
January1st to 15thNight
10%14%6%12%7%5%9%7%6%413%
3135
16th to endNight
9%13%7%13%9%5%8%8%5%5%12%
3192
February1st to 15thNight
9%11%47%7%6%10%8%5%5%22%
2703
16th to endNight
6%12%5%9%8%47%7%46%26%
2354
March1st to 15thNight
11%11%5%7%6%45%5%45%33%
2437
16th to endNight
14%11%5%6%5%34445%35%
2388
April1st to 15thNight
12%10%37%5%23445%39%
2097
16th to endNight
14%8%36%5%34345%39%
1809
May1st to 15thNight
18%9%5%7%334445%33%
1680
16th to endNight
20%7%2443445%7%35%
1732
June1st to 15thNight
18%6%34423447%39%
1470
16th to endNight
14%5%245%345%6%8%38%
1393
July1st to 15thNight
11%43432446%10%45%
1365
16th to endNight
13%5%23324448%48%
1556
August1st to 15thNight
9%5%25%4345%5%7%44%
1551
16th to endNight
14%7%1432335%7%45%
1925
September1st to 15thNight
15%7%26%334447%40%
1950
16th to endNight
23%9%35%5%24345%32%
2127
October1st to 15thNight
21%13%35%5%33336%29%
2340
16th to endNight
22%18%46%5%33345%21%
2632
November1st to 15thNight
18%20%6%9%7%3433318%
2871
16th to endNight
17%15%7%14%9%5%5%33313%
2940
December1st to 15thNight
10%12%7%14%13%6%8%6%4412%
3003
16th to endNight
13%17%7%13%11%6%6%44310%
3360

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%6%12%8%48%6%5%5%15%
1463
16th to endDay
10%13%6%11%9%6%8%7%7%5%13%
1736
February1st to 15thDay
8%12%48%7%6%8%10%5%422%
1817
16th to endDay
7%12%5%11%9%47%5%5%5%25%
1690
March1st to 15thDay
9%13%6%8%8%35%45%5%30%
2184
16th to endDay
14%11%48%6%44445%32%
2539
April1st to 15thDay
10%10%47%6%24446%37%
2511
16th to endDay
16%8%35%5%245%46%38%
2751
May1st to 15thDay
17%11%47%6%3445%6%28%
2931
16th to endDay
21%6%345%245%5%6%34%
3082
June1st to 15thDay
20%6%25%5%345%5%8%32%
3150
16th to endDay
19%6%25%6%35%6%6%6%30%
2975
July1st to 15thDay
16%5%25%435%45%7%38%
2925
16th to endDay
15%5%25%43446%8%39%
2961
August1st to 15thDay
12%5%25%5%445%6%8%39%
2661
16th to endDay
15%6%26%5%3445%7%39%
2629
September1st to 15thDay
18%7%35%5%2445%6%36%
2340
16th to endDay
26%10%36%42333430%
2148
October1st to 15thDay
22%18%47%5%24345%22%
1950
16th to endDay
23%23%6%5%5%23325%19%
1943
November1st to 15thDay
20%19%7%9%7%3433316%
1647
16th to endDay
16%19%7%16%10%344349%
1680
December1st to 15thDay
10%14%8%14%9%6%7%6%5%410%
1616
16th to endDay
15%15%9%11%10%46%5%5%5%9%
1568
January1st to 15thNight
10%14%6%12%8%5%9%7%6%413%
3135
16th to endNight
9%13%7%12%9%5%8%9%6%412%
3192
February1st to 15thNight
9%11%5%7%6%6%11%8%5%5%22%
2696
16th to endNight
6%12%5%9%8%47%7%45%26%
2354
March1st to 15thNight
11%10%5%7%6%35%5%46%32%
2450
16th to endNight
14%10%5%6%5%33445%35%
2388
April1st to 15thNight
12%11%37%5%2335%5%40%
2097
16th to endNight
14%8%36%5%25%346%39%
1809
May1st to 15thNight
19%9%37%5%24345%34%
1679
16th to endNight
20%7%245%25%45%7%35%
1732
June1st to 15thNight
19%6%24423447%39%
1470
16th to endNight
14%4345%246%6%8%39%
1393
July1st to 15thNight
11%5%2432446%9%45%
1365
16th to endNight
14%5%13413348%48%
1556
August1st to 15thNight
10%5%26%4345%6%6%44%
1551
16th to endNight
15%6%2442335%7%45%
1925
September1st to 15thNight
15%7%2443445%7%40%
1950
16th to endNight
24%9%35%424345%32%
2127
October1st to 15thNight
21%13%35%6%23345%29%
2340
16th to endNight
22%19%37%5%33345%21%
2632
November1st to 15thNight
18%20%6%9%7%3433318%
2871
16th to endNight
18%15%7%13%10%5%423313%
2940
December1st to 15thNight
10%12%7%14%13%6%8%6%4412%
3003
16th to endNight
14%17%7%12%12%6%6%5%4310%
3360

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
11%14%6%12%8%48%7%6%414%
1463
16th to endDay
10%13%6%10%9%6%8%7%7%5%13%
1736
February1st to 15thDay
8%11%5%8%7%5%9%10%5%5%21%
1817
16th to endDay
7%12%5%11%9%46%5%6%5%24%
1690
March1st to 15thDay
10%13%5%9%7%35%45%5%29%
2184
16th to endDay
14%10%48%6%34446%31%
2537
April1st to 15thDay
10%11%47%6%23447%37%
2511
16th to endDay
16%9%35%43345%5%37%
2751
May1st to 15thDay
18%12%48%5%34446%28%
2931
16th to endDay
21%6%344245%5%6%34%
3082
June1st to 15thDay
20%6%25%5%35%45%8%31%
3150
16th to endDay
19%6%35%6%35%5%6%7%30%
2975
July1st to 15thDay
16%5%25%5%35%45%6%38%
2925
16th to endDay
16%5%25%43446%8%38%
2961
August1st to 15thDay
12%5%25%5%45%46%8%38%
2661
16th to endDay
15%6%25%5%3445%7%38%
2629
September1st to 15thDay
19%7%35%5%2445%6%36%
2340
16th to endDay
27%10%35%42334429%
2148
October1st to 15thDay
21%18%5%6%5%33345%22%
1950
16th to endDay
23%24%5%6%42323419%
1943
November1st to 15thDay
21%19%7%9%8%2433416%
1647
16th to endDay
16%18%8%16%10%3443310%
1680
December1st to 15thDay
11%14%8%14%10%6%7%6%5%410%
1616
16th to endDay
15%16%9%11%9%5%6%5%5%5%9%
1568
January1st to 15thNight
11%14%6%11%8%6%8%7%7%413%
3135
16th to endNight
9%14%7%12%8%5%8%8%6%412%
3192
February1st to 15thNight
9%11%5%7%7%6%11%8%5%6%21%
2696
16th to endNight
6%13%5%9%8%47%6%45%26%
2354
March1st to 15thNight
11%10%48%6%35%5%46%32%
2450
16th to endNight
13%11%5%6%5%3335%5%35%
2388
April1st to 15thNight
12%10%37%5%23345%40%
2097
16th to endNight
14%8%26%6%24445%39%
1809
May1st to 15thNight
19%9%47%5%24445%33%
1679
16th to endNight
20%7%2443445%6%35%
1732
June1st to 15thNight
19%6%23423446%39%
1470
16th to endNight
14%5%25%4246%6%8%39%
1393
July1st to 15thNight
11%5%2443445%9%45%
1365
16th to endNight
14%413424239%48%
1556
August1st to 15thNight
10%5%26%5%3445%7%43%
1551
16th to endNight
15%6%2342335%7%45%
1925
September1st to 15thNight
16%6%34434448%40%
1950
16th to endNight
24%9%35%424335%32%
2127
October1st to 15thNight
21%12%46%5%23346%29%
2340
16th to endNight
23%19%36%6%34245%21%
2632
November1st to 15thNight
18%20%6%9%7%3333418%
2871
16th to endNight
18%16%7%12%10%5%433313%
2940
December1st to 15thNight
10%11%7%13%13%5%7%6%4412%
3003
16th to endNight
14%17%7%13%11%5%6%5%4310%
3360

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
69%38%12%4
1464
16th to endDay
69%36%14%6%
1736
February1st to 15thDay
62%310%16%6%
1818
16th to endDay
59%310%20%5%
1690
March1st to 15thDay
56%412%17%7%1
2184
16th to endDay
55%310%18%9%2
2539
April1st to 15thDay
47%49%21%14%2
2511
16th to endDay
48%39%23%12%1
2751
May1st to 15thDay
57%49%20%8%
2931
16th to endDay
50%6%11%20%11%
3086
June1st to 15thDay
50%6%10%21%11%
3150
16th to endDay
52%6%14%19%6%
2975
July1st to 15thDay
43%6%12%29%8%
2766
16th to endDay
43%6%15%25%7%
2791
August1st to 15thDay
41%7%16%26%6%
2646
16th to endDay
44%5%16%25%7%
2629
September1st to 15thDay
48%5%14%25%6%
2340
16th to endDay
58%5%14%18%3
2148
October1st to 15thDay
65%311%15%4
1950
16th to endDay
70%311%13%1
1943
November1st to 15thDay
72%311%8%3
1647
16th to endDay
78%47%6%2
1680
December1st to 15thDay
75%48%9%2
1616
16th to endDay
75%27%9%4
1568
January1st to 15thNight
70%38%14%3
3135
16th to endNight
71%46%13%4
3192
February1st to 15thNight
61%410%16%6%
2706
16th to endNight
57%412%20%4
2354
March1st to 15thNight
52%413%16%10%1
2450
16th to endNight
50%311%21%10%3
2388
April1st to 15thNight
46%39%21%17%2
2097
16th to endNight
46%39%22%16%2
1809
May1st to 15thNight
53%48%19%13%
1680
16th to endNight
48%412%19%13%1
1734
June1st to 15thNight
45%410%22%16%
1470
16th to endNight
42%6%14%25%10%
1393
July1st to 15thNight
33%6%16%31%12%
1295
16th to endNight
36%413%32%11%1
1463
August1st to 15thNight
38%6%13%29%10%1
1542
16th to endNight
39%418%27%9%
1925
September1st to 15thNight
43%5%15%27%8%
1950
16th to endNight
54%413%22%4
2127
October1st to 15thNight
57%313%20%5%
2340
16th to endNight
65%411%15%2
2632
November1st to 15thNight
71%310%11%2
2871
16th to endNight
76%38%8%2
2940
December1st to 15thNight
73%5%9%8%2
3003
16th to endNight
78%35%9%2
3360

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
17%16%42%21%2
180
16th to endDay
17%11%36%24%7%1
192
February1st to 15thDay
24%13%38%21%2
180
16th to endDay
21%21%36%13%5%1
159
March1st to 15thDay
13%13%42%20%7%2
180
16th to endDay
19%15%33%18%8%2
267
April1st to 15thDay
17%13%30%27%10%1
390
16th to endDay
22%12%35%21%8%
554
May1st to 15thDay
26%16%30%18%6%1
618
16th to endDay
26%12%30%18%10%1
677
June1st to 15thDay
23%13%33%18%7%2
645
16th to endDay
24%9%27%22%11%4
587
July1st to 15thDay
19%13%30%22%12%2
550
16th to endDay
18%8%25%25%15%6%
595
August1st to 15thDay
15%6%28%26%17%4
549
16th to endDay
21%7%29%26%14%1
541
September1st to 15thDay
22%9%31%24%10%1
375
16th to endDay
40%12%26%15%4
286
October1st to 15thDay
42%15%23%13%22
180
16th to endDay
42%8%38%8%1
192
November1st to 15thDay
34%10%32%15%7%
180
16th to endDay
31%17%34%12%3
180
December1st to 15thDay
17%9%45%21%32
180
16th to endDay
18%10%38%22%6%3
192
January1st to 15thNight
20%13%34%23%7%
1050
16th to endNight
17%11%37%25%7%
1120
February1st to 15thNight
15%10%36%27%9%1
1030
16th to endNight
13%10%32%28%11%3
884
March1st to 15thNight
17%12%31%25%11%1
770
16th to endNight
21%10%28%25%10%4
672
April1st to 15thNight
18%10%29%31%9%
629
16th to endNight
19%8%28%32%9%1
624
May1st to 15thNight
25%9%32%24%7%1
630
16th to endNight
24%6%27%28%12%
659
June1st to 15thNight
23%5%28%29%11%1
630
16th to endNight
17%6%23%36%15%1
597
July1st to 15thNight
12%7%31%31%16%1
555
16th to endNight
17%323%30%21%3
612
August1st to 15thNight
13%5%27%27%23%3
575
16th to endNight
19%427%29%17%1
621
September1st to 15thNight
22%6%26%30%13%1
585
16th to endNight
30%6%27%23%9%1
672
October1st to 15thNight
31%11%27%23%6%
780
16th to endNight
36%8%28%18%7%
832
November1st to 15thNight
31%12%28%19%5%2
1025
16th to endNight
29%12%31%21%41
1050
December1st to 15thNight
17%10%37%25%7%1
1050
16th to endNight
23%10%30%23%9%2
1120
Page generated at 2019-06-20 08:02:27. Version ac04

Copyright 2019 A. Danko


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