Grand Island KOA Journey
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Grand Island KOA Journey clear sky chart from 2005-11-06 to 2024-03-06.

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
39%
24843
23%
79694
12%
24740
49%
24740
31%
46799

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 10thNight
33%
939
20%
4372
10%
926
44%
926
17%
2767
January11th to 20thNight
30%
948
25%
4033
10%
930
40%
930
20%
2269
January21st to endNight
30%
1038
16%
4379
9%
1023
40%
1023
18%
2898
February1st to 10thNight
26%
950
17%
2470
6%
950
33%
950
26%
1699
February11th to 20thNight
31%
779
19%
2253
8%
775
39%
775
29%
1402
February21st to endNight
25%
628
25%
1884
5%
628
42%
628
33%
1080
March1st to 10thNight
27%
684
23%
2168
9%
684
40%
684
30%
1245
March11th to 20thNight
30%
540
24%
1980
16%
540
43%
540
27%
1129
March21st to endNight
23%
594
16%
2178
8%
594
34%
594
19%
1384
April1st to 10thNight
26%
540
18%
1914
9%
540
41%
540
25%
1129
April11th to 20thNight
26%
533
21%
1646
11%
533
39%
533
27%
1004
April21st to endNight
37%
540
22%
1620
18%
540
46%
540
28%
989
May1st to 10thNight
36%
540
17%
1620
11%
540
44%
540
26%
1041
May11th to 20thNight
35%
531
16%
1593
11%
531
43%
531
28%
1008
May21st to endNight
40%
583
13%
1746
7%
582
46%
582
27%
1131
June1st to 10thNight
57%
540
19%
1612
12%
540
59%
540
39%
887
June11th to 20thNight
47%
540
21%
1440
8%
540
52%
540
41%
845
June21st to endNight
54%
540
22%
1440
11%
540
59%
540
48%
802
July1st to 10thNight
65%
525
18%
1400
11%
525
66%
525
42%
825
July11th to 20thNight
69%
522
22%
1481
16%
522
73%
522
48%
780
July21st to endNight
69%
591
23%
1673
19%
558
73%
558
46%
877
August1st to 10thNight
66%
537
19%
1601
20%
534
68%
534
37%
932
August11th to 20thNight
62%
534
27%
1600
26%
534
69%
534
43%
852
August21st to endNight
60%
594
28%
1827
25%
594
68%
594
44%
963
September1st to 10thNight
55%
540
27%
1930
25%
540
65%
540
41%
932
September11th to 20thNight
49%
540
30%
1980
25%
540
61%
540
38%
991
September21st to endNight
46%
540
30%
1980
21%
540
60%
540
37%
975
October1st to 10thNight
40%
562
29%
2002
22%
562
51%
562
30%
1106
October11th to 20thNight
35%
720
29%
2160
13%
720
46%
720
37%
1176
October21st to endNight
39%
886
28%
2470
13%
886
48%
886
37%
1423
November1st to 10thNight
43%
925
31%
2405
12%
925
54%
925
48%
1297
November11th to 20thNight
33%
950
31%
2470
10%
950
47%
950
40%
1427
November21st to endNight
38%
950
27%
2470
12%
950
47%
950
40%
1444
December1st to 10thNight
30%
950
25%
2470
9%
950
43%
950
36%
1502
December11th to 20thNight
31%
949
28%
2854
9%
948
43%
948
31%
1618
December21st to endNight
28%
1041
16%
4573
8%
1026
43%
1026
17%
2970

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
9%6%35%5%3445%7%48%
79087
Night
9%6%35%42445%7%50%
80465
TransparencyDay
35%7%14%25%16%3
78805
Night
33%6%14%26%18%3
80270
SeeingDay
13%10%31%31%14%2
14753
Night
11%9%36%34%9%1
24869

By Month

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 10thDay
6%14%46%7%45%45%6%38%
2538
11th to 20thDay
6%11%5%9%6%345%5%7%39%
2818
21st to endDay
7%8%5%13%6%33436%43%
3135
February1st to 10thDay
9%9%5%7%7%345%6%7%38%
1710
11th to 20thDay
6%7%46%5%35%5%6%7%47%
1830
21st to endDay
9%8%25%5%345%45%50%
1570
March1st to 10thDay
8%5%35%42445%7%52%
1908
11th to 20thDay
15%8%35%4235%5%7%43%
1980
21st to endDay
14%11%48%5%345%46%37%
2178
April1st to 10thDay
12%7%25%43345%7%48%
2042
11th to 20thDay
14%8%25%5%34446%44%
2260
21st to endDay
17%6%25%5%35%35%6%41%
2340
May1st to 10thDay
15%6%35%435%6%6%8%40%
2340
11th to 20thDay
16%7%35%5%3445%7%42%
2302
21st to endDay
13%6%35%6%45%6%6%8%37%
2531
June1st to 10thDay
6%3144345%6%9%54%
2343
11th to 20thDay
8%4245%245%6%7%51%
2520
21st to endDay
6%3135%35%5%7%10%52%
2520
July1st to 10thDay
7%4245%35%46%9%51%
2520
11th to 20thDay
4324435%5%6%8%56%
2426
21st to endDay
6%4245%345%7%9%50%
2546
August1st to 10thDay
7%5%25%6%35%6%7%9%44%
2328
11th to 20thDay
7%32442446%9%53%
2301
21st to endDay
8%5%25%43445%7%54%
2525
September1st to 10thDay
12%434423346%55%
2030
11th to 20thDay
9%42443335%7%57%
1980
21st to endDay
9%41332435%7%59%
1980
October1st to 10thDay
15%6%24413435%53%
1938
11th to 20thDay
11%5%23422346%58%
1800
21st to endDay
13%7%24323245%54%
1882
November1st to 10thDay
7%5%2433345%8%57%
1673
11th to 20thDay
7%6%245%23347%56%
1710
21st to endDay
11%7%35%433347%50%
1710
December1st to 10thDay
7%6%45%435%5%5%7%50%
1710
11th to 20thDay
6%8%46%5%3445%6%48%
2161
21st to endDay
13%10%311%6%345%5%5%35%
3002
January1st to 10thNight
5%13%49%8%345%6%6%37%
4417
11th to 20thNight
6%8%36%5%36%5%5%6%48%
4144
21st to endNight
8%10%411%5%345%5%5%40%
4532
February1st to 10thNight
9%9%47%6%35%5%46%42%
2470
11th to 20thNight
5%7%36%6%35%6%6%6%46%
2253
21st to endNight
6%7%35%5%3445%6%52%
1884
March1st to 10thNight
9%5%445%34346%52%
2168
11th to 20thNight
13%8%34323446%50%
1980
21st to endNight
14%8%36%5%35%5%5%7%40%
2178
April1st to 10thNight
11%6%35%5%25%45%7%48%
1914
11th to 20thNight
11%7%244345%6%9%43%
1646
21st to endNight
14%5%2442445%7%48%
1620
May1st to 10thNight
15%6%25%43446%7%44%
1620
11th to 20thNight
11%6%45%5%335%5%7%45%
1593
21st to endNight
12%6%25%435%5%6%11%41%
1745
June1st to 10thNight
5%42342447%10%54%
1612
11th to 20thNight
7%42443445%8%56%
1440
21st to endNight
43334235%7%9%58%
1440
July1st to 10thNight
6%325%4245%8%9%52%
1440
11th to 20thNight
3212425%5%7%8%60%
1530
21st to endNight
42244346%6%12%53%
1772
August1st to 10thNight
6%425%435%6%7%9%51%
1611
11th to 20thNight
5%41443436%9%57%
1600
21st to endNight
7%423324447%60%
1827
September1st to 10thNight
9%223323436%63%
1930
11th to 20thNight
7%324424347%58%
1980
21st to endNight
7%32342445%6%59%
1980
October1st to 10thNight
15%41432345%6%53%
2002
11th to 20thNight
10%5%14323345%59%
2160
21st to endNight
12%5%23423345%57%
2470
November1st to 10thNight
4423323447%63%
2405
11th to 20thNight
7%5%2442435%7%57%
2470
21st to endNight
9%6%24324448%55%
2470
December1st to 10thNight
6%7%3442445%8%52%
2470
11th to 20thNight
7%5%25%43345%7%53%
3036
21st to endNight
15%10%39%5%23346%39%
4656

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 10thDay
44%8%16%22%9%1
2539
11th to 20thDay
42%8%17%18%13%2
2818
21st to endDay
44%6%13%23%12%1
3135
February1st to 10thDay
44%7%16%21%10%2
1710
11th to 20thDay
36%6%16%24%15%4
1840
21st to endDay
35%6%12%27%15%5%
1570
March1st to 10thDay
32%6%14%27%18%3
1908
11th to 20thDay
40%6%12%25%15%2
1980
21st to endDay
49%6%16%21%8%1
2178
April1st to 10thDay
36%6%16%25%15%2
2042
11th to 20thDay
40%6%14%23%14%3
2263
21st to endDay
42%7%13%24%14%1
2340
May1st to 10thDay
41%8%15%21%15%1
2340
11th to 20thDay
41%8%15%23%13%
2306
21st to endDay
42%10%16%20%11%1
2531
June1st to 10thDay
25%8%18%32%15%2
2343
11th to 20thDay
30%8%14%27%18%3
2520
21st to endDay
25%9%16%29%18%4
2520
July1st to 10thDay
28%7%17%28%18%2
2451
11th to 20thDay
23%8%14%29%21%5%
2352
21st to endDay
27%9%17%30%16%1
2405
August1st to 10thDay
31%11%18%26%12%1
2314
11th to 20thDay
27%6%16%31%18%2
2301
21st to endDay
28%7%13%22%24%5%
2525
September1st to 10thDay
32%6%12%23%21%7%
2030
11th to 20thDay
28%6%12%29%22%3
1980
21st to endDay
25%5%10%33%26%1
1980
October1st to 10thDay
34%5%9%26%25%2
1938
11th to 20thDay
28%410%29%21%8%
1800
21st to endDay
34%412%23%22%5%
1882
November1st to 10thDay
26%5%15%29%22%3
1673
11th to 20thDay
30%5%11%26%24%4
1710
21st to endDay
35%412%26%19%4
1710
December1st to 10thDay
33%6%16%28%14%2
1710
11th to 20thDay
36%6%14%31%13%
2159
21st to endDay
49%7%12%20%11%1
3002
January1st to 10thNight
44%7%13%23%13%1
4417
11th to 20thNight
35%7%16%26%16%1
4144
21st to endNight
44%7%11%21%15%1
4532
February1st to 10thNight
42%7%13%22%13%3
2470
11th to 20thNight
35%7%15%24%15%3
2253
21st to endNight
31%5%13%21%22%8%
1884
March1st to 10thNight
34%412%27%19%4
2168
11th to 20thNight
35%5%11%25%21%4
1980
21st to endNight
43%7%15%23%11%2
2178
April1st to 10thNight
36%6%14%23%18%2
1914
11th to 20thNight
36%6%15%27%14%2
1646
21st to endNight
34%8%12%26%18%2
1620
May1st to 10thNight
39%7%14%24%14%1
1620
11th to 20thNight
37%7%17%24%14%1
1594
21st to endNight
37%10%18%22%12%2
1746
June1st to 10thNight
23%10%19%30%17%2
1612
11th to 20thNight
26%7%16%26%18%6%
1440
21st to endNight
21%7%17%31%20%4
1440
July1st to 10thNight
25%9%16%26%19%4
1400
11th to 20thNight
20%7%17%27%24%5%
1481
21st to endNight
20%8%19%33%17%3
1673
August1st to 10thNight
27%10%20%28%13%3
1601
11th to 20thNight
24%7%16%32%19%2
1600
21st to endNight
23%7%13%25%24%8%
1827
September1st to 10thNight
23%5%11%27%24%10%
1930
11th to 20thNight
26%5%11%30%24%5%
1980
21st to endNight
25%6%11%27%29%3
1980
October1st to 10thNight
32%6%11%25%23%3
2002
11th to 20thNight
27%5%8%25%26%8%
2160
21st to endNight
30%412%26%22%7%
2470
November1st to 10thNight
20%5%13%29%26%6%
2405
11th to 20thNight
28%411%29%24%4
2470
21st to endNight
29%413%27%23%4
2470
December1st to 10thNight
30%6%14%30%18%2
2470
11th to 20thNight
30%5%13%36%16%1
3037
21st to endNight
45%6%12%25%11%1
4656

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 10thDay
16%16%35%24%7%1
270
11th to 20thDay
16%17%33%26%7%1
270
21st to endDay
14%11%44%23%7%1
297
February1st to 10thDay
14%14%45%21%6%
270
11th to 20thDay
11%10%46%25%6%1
270
21st to endDay
14%17%49%15%5%
225
March1st to 10thDay
12%14%48%21%41
255
11th to 20thDay
24%11%35%20%9%
240
21st to endDay
25%16%38%16%4
264
April1st to 10thDay
16%20%42%19%4
302
11th to 20thDay
20%13%37%25%5%
541
21st to endDay
21%16%32%20%9%2
600
May1st to 10thDay
16%12%33%28%10%1
603
11th to 20thDay
18%12%32%25%11%3
625
21st to endDay
15%10%31%30%13%1
679
June1st to 10thDay
5%6%26%36%21%5%
630
11th to 20thDay
9%6%35%33%15%2
630
21st to endDay
7%8%31%34%18%2
630
July1st to 10thDay
9%317%41%26%5%
621
11th to 20thDay
6%219%45%22%5%
618
21st to endDay
7%320%40%27%3
684
August1st to 10thDay
8%318%46%22%3
626
11th to 20thDay
6%420%44%24%2
615
21st to endDay
9%323%39%23%4
644
September1st to 10thDay
15%427%37%13%4
320
11th to 20thDay
6%7%29%37%15%6%
270
21st to endDay
14%9%31%28%14%3
270
October1st to 10thDay
23%9%24%31%9%4
270
11th to 20thDay
13%14%38%23%10%1
270
21st to endDay
17%19%32%23%8%1
297
November1st to 10thDay
11%17%40%21%8%2
270
11th to 20thDay
9%16%47%20%7%
270
21st to endDay
22%13%33%20%10%1
270
December1st to 10thDay
7%11%43%32%5%1
270
11th to 20thDay
15%11%40%28%6%
270
21st to endDay
19%12%48%20%2
297
January1st to 10thNight
11%12%37%33%6%1
950
11th to 20thNight
12%12%40%29%6%1
950
21st to endNight
11%9%42%31%7%
1045
February1st to 10thNight
13%12%43%27%4
950
11th to 20thNight
10%11%43%31%5%
779
21st to endNight
10%13%48%24%5%
628
March1st to 10thNight
12%14%43%27%31
684
11th to 20thNight
16%11%40%27%5%1
540
21st to endNight
18%13%41%23%5%
594
April1st to 10thNight
16%12%43%26%3
540
11th to 20thNight
16%13%43%25%3
533
21st to endNight
18%12%31%32%7%1
540
May1st to 10thNight
17%10%34%30%8%
540
11th to 20thNight
15%8%38%31%8%
531
21st to endNight
14%8%34%32%12%1
584
June1st to 10thNight
7%5%27%45%14%2
540
11th to 20thNight
7%5%37%40%11%
540
21st to endNight
5%433%44%14%
540
July1st to 10thNight
6%321%45%25%1
525
11th to 20thNight
3221%53%20%1
522
21st to endNight
4218%52%23%
591
August1st to 10thNight
6%219%50%20%2
537
11th to 20thNight
6%224%49%18%
534
21st to endNight
7%325%43%21%2
594
September1st to 10thNight
11%228%42%16%1
540
11th to 20thNight
9%434%37%15%1
540
21st to endNight
7%7%37%35%13%1
540
October1st to 10thNight
17%7%32%31%12%
562
11th to 20thNight
13%11%38%30%7%
720
21st to endNight
14%12%32%31%10%
886
November1st to 10thNight
7%10%37%39%6%1
925
11th to 20thNight
10%11%42%30%7%
950
21st to endNight
12%11%37%31%10%
950
December1st to 10thNight
10%11%44%29%5%
950
11th to 20thNight
13%9%42%31%5%
950
21st to endNight
16%13%38%28%5%
1045
Page generated at 2024-03-03 05:28:55. Version ac07

Copyright © 2024 Attilla Danko.


Grand Island KOA Journey Clear Sky Chart |Charts Home