Omaha
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Omaha clear sky chart from 2005-11-06 to 2024-03-28.

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%
24925
20%
80633
12%
24825
47%
24825
26%
50380

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
31%
943
12%
4090
8%
926
39%
926
14%
3115
January11th to 20thNight
28%
949
19%
4025
9%
930
36%
930
15%
2627
January21st to endNight
26%
1034
12%
4510
6%
1023
35%
1023
13%
3254
February1st to 10thNight
25%
950
14%
2470
5%
950
30%
950
23%
1757
February11th to 20thNight
29%
929
17%
2404
6%
925
35%
925
28%
1602
February21st to endNight
26%
628
23%
1884
5%
628
41%
628
28%
1168
March1st to 10thNight
29%
591
23%
2111
11%
591
43%
591
25%
1244
March11th to 20thNight
30%
570
21%
2090
14%
570
41%
570
22%
1266
March21st to endNight
23%
615
12%
2255
7%
615
31%
615
14%
1563
April1st to 10thNight
25%
540
18%
1918
11%
540
37%
540
22%
1155
April11th to 20thNight
27%
533
23%
1684
13%
533
42%
533
25%
1048
April21st to endNight
32%
540
19%
1620
13%
540
43%
540
24%
1049
May1st to 10thNight
36%
540
15%
1620
10%
540
43%
540
24%
1075
May11th to 20thNight
38%
531
18%
1594
11%
531
46%
531
26%
1022
May21st to endNight
42%
583
12%
1639
7%
582
45%
582
26%
1107
June1st to 10thNight
59%
540
22%
1440
12%
540
63%
540
41%
844
June11th to 20thNight
50%
540
21%
1440
9%
540
55%
540
41%
854
June21st to endNight
55%
540
21%
1440
9%
540
60%
540
44%
814
July1st to 10thNight
68%
525
18%
1502
11%
525
70%
525
44%
803
July11th to 20thNight
70%
522
21%
1566
16%
522
74%
522
49%
783
July21st to endNight
72%
591
24%
1673
22%
558
75%
558
49%
841
August1st to 10thNight
67%
537
20%
1601
21%
534
69%
534
35%
934
August11th to 20thNight
65%
534
27%
1600
28%
534
71%
534
42%
864
August21st to endNight
62%
594
27%
1831
27%
594
68%
594
41%
977
September1st to 10thNight
57%
540
24%
1849
22%
540
65%
540
36%
960
September11th to 20thNight
54%
540
29%
1980
25%
540
64%
540
38%
978
September21st to endNight
47%
540
30%
1980
23%
540
60%
540
36%
997
October1st to 10thNight
41%
668
25%
2108
16%
668
49%
668
32%
1228
October11th to 20thNight
35%
720
26%
2160
12%
720
45%
720
32%
1253
October21st to endNight
37%
792
24%
2376
13%
792
46%
792
30%
1419
November1st to 10thNight
41%
890
28%
2370
12%
890
52%
890
39%
1355
November11th to 20thNight
33%
950
26%
2553
9%
950
45%
950
33%
1548
November21st to endNight
34%
950
23%
2660
12%
950
43%
950
32%
1645
December1st to 10thNight
29%
950
18%
2660
7%
950
38%
950
26%
1747
December11th to 20thNight
31%
948
21%
3135
8%
948
40%
948
23%
1916
December21st to endNight
26%
1038
12%
4795
7%
1026
38%
1026
12%
3568

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
11%7%37%5%35%5%5%7%42%
78885
Night
11%7%36%5%3445%7%45%
81161
TransparencyDay
41%7%13%24%13%2
78608
Night
38%6%13%25%15%2
80958
SeeingDay
15%9%30%29%14%3
14858
Night
14%9%33%34%10%1
24954

By Month

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 10thDay
9%11%6%13%11%445%5%6%25%
2847
11th to 20thDay
9%11%5%9%6%38%5%6%8%30%
2850
21st to endDay
10%14%6%14%9%45%445%25%
3135
February1st to 10thDay
9%12%5%10%7%45%5%5%7%32%
1710
11th to 20thDay
10%9%48%6%345%5%8%39%
1679
21st to endDay
10%8%5%7%6%345%5%6%41%
1570
March1st to 10thDay
11%10%47%435%445%42%
2068
11th to 20thDay
14%10%46%5%34447%40%
2090
21st to endDay
19%13%46%5%3445%6%30%
2255
April1st to 10thDay
16%8%36%5%33347%43%
2042
11th to 20thDay
16%9%36%5%345%5%5%39%
2224
21st to endDay
20%6%25%5%25%5%5%7%37%
2340
May1st to 10thDay
15%7%46%6%35%5%5%7%38%
2340
11th to 20thDay
15%7%36%6%3446%8%38%
2302
21st to endDay
16%6%36%6%45%5%7%8%33%
2633
June1st to 10thDay
8%5%25%5%35%5%6%9%47%
2520
11th to 20thDay
9%425%5%25%5%7%8%48%
2520
21st to endDay
8%5%25%5%35%5%6%8%49%
2520
July1st to 10thDay
8%42442447%9%52%
2408
11th to 20thDay
6%424435%5%5%7%55%
2340
21st to endDay
5%335%4346%6%11%50%
2546
August1st to 10thDay
7%5%26%5%46%7%6%10%41%
2328
11th to 20thDay
9%3245%35%6%6%8%49%
2301
21st to endDay
8%4245%3445%8%52%
2525
September1st to 10thDay
13%5%13423447%54%
2108
11th to 20thDay
10%6%2443345%6%53%
1980
21st to endDay
11%42433445%5%56%
1980
October1st to 10thDay
15%5%233245%47%50%
1832
11th to 20thDay
12%6%34423345%55%
1800
21st to endDay
14%7%36%43345%5%46%
1980
November1st to 10thDay
10%5%2432435%6%55%
1705
11th to 20thDay
10%8%28%6%445%36%45%
1625
21st to endDay
14%8%445%2335%8%43%
1520
December1st to 10thDay
9%8%37%5%35%5%5%7%43%
1520
11th to 20thDay
9%10%48%6%45%5%5%7%36%
1918
21st to endDay
15%10%6%14%8%45%5%45%23%
2824
January1st to 10thNight
8%10%5%17%12%4445%5%27%
4108
11th to 20thNight
9%11%5%6%5%38%6%8%6%33%
4120
21st to endNight
12%13%5%11%7%35%45%6%29%
4532
February1st to 10thNight
12%9%49%6%4445%6%37%
2470
11th to 20thNight
9%9%36%4345%6%7%43%
2403
21st to endNight
9%7%5%6%5%335%46%48%
1884
March1st to 10thNight
11%8%45%334446%48%
2111
11th to 20thNight
15%9%36%32335%5%46%
2090
21st to endNight
18%11%47%5%35%46%8%30%
2255
April1st to 10thNight
13%7%25%425%45%6%46%
1918
11th to 20thNight
12%8%26%434446%46%
1684
21st to endNight
16%7%35%434447%44%
1620
May1st to 10thNight
15%6%36%5%35%5%6%8%40%
1620
11th to 20thNight
13%6%25%5%3445%8%45%
1593
21st to endNight
13%7%36%5%35%5%6%8%40%
1638
June1st to 10thNight
6%315%325%5%5%10%55%
1440
11th to 20thNight
7%4234246%8%10%50%
1440
21st to endNight
4324335%5%5%9%57%
1440
July1st to 10thNight
5%4234335%5%10%57%
1547
11th to 20thNight
321333346%10%63%
1620
21st to endNight
431443446%10%59%
1772
August1st to 10thNight
5%325%5%346%7%9%51%
1611
11th to 20thNight
7%324433448%58%
1600
21st to endNight
8%31342445%8%58%
1831
September1st to 10thNight
10%313423447%58%
1849
11th to 20thNight
10%41342346%7%58%
1980
21st to endNight
10%423323445%60%
1980
October1st to 10thNight
14%5%2432445%7%51%
2108
11th to 20thNight
13%6%24422445%53%
2160
21st to endNight
13%7%24333345%51%
2376
November1st to 10thNight
8%5%2332445%7%57%
2370
11th to 20thNight
10%6%25%43335%7%52%
2553
21st to endNight
12%7%44423346%51%
2660
December1st to 10thNight
9%9%36%6%3445%7%44%
2660
11th to 20thNight
9%9%36%5%24447%46%
3279
21st to endNight
18%13%6%11%5%2334430%
4839

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
58%6%13%15%6%1
2848
11th to 20thDay
52%6%13%22%7%
2850
21st to endDay
59%8%12%14%7%
3135
February1st to 10thDay
52%7%14%17%10%1
1710
11th to 20thDay
44%6%12%24%13%2
1688
21st to endDay
43%7%11%22%14%3
1570
March1st to 10thDay
44%5%12%25%13%2
2068
11th to 20thDay
46%6%11%23%13%2
2090
21st to endDay
55%6%15%16%7%1
2255
April1st to 10thDay
44%5%12%26%12%1
2042
11th to 20thDay
45%7%12%22%12%2
2224
21st to endDay
46%7%11%23%12%1
2340
May1st to 10thDay
46%9%13%20%13%1
2340
11th to 20thDay
43%8%14%24%11%
2306
21st to endDay
46%10%14%18%10%2
2633
June1st to 10thDay
32%9%16%28%13%2
2520
11th to 20thDay
32%8%14%30%16%1
2520
21st to endDay
31%9%15%27%14%3
2520
July1st to 10thDay
27%8%16%32%15%3
2344
11th to 20thDay
27%8%14%27%19%4
2271
21st to endDay
25%8%19%30%17%1
2405
August1st to 10thDay
35%11%17%24%11%1
2314
11th to 20thDay
30%9%14%30%16%1
2301
21st to endDay
30%7%13%27%19%5%
2525
September1st to 10thDay
31%5%13%28%18%5%
2108
11th to 20thDay
30%6%11%33%18%1
1980
21st to endDay
30%5%10%32%22%1
1980
October1st to 10thDay
35%5%13%26%20%1
1832
11th to 20thDay
33%410%25%23%4
1800
21st to endDay
39%5%13%21%19%3
1980
November1st to 10thDay
30%415%28%20%3
1705
11th to 20thDay
40%7%12%24%17%1
1625
21st to endDay
41%412%30%12%1
1520
December1st to 10thDay
40%6%17%24%12%1
1520
11th to 20thDay
46%6%17%26%5%
1915
21st to endDay
61%7%10%16%6%
2824
January1st to 10thNight
57%7%12%15%9%1
4108
11th to 20thNight
47%6%15%22%10%1
4120
21st to endNight
53%7%15%15%8%1
4532
February1st to 10thNight
47%6%13%20%12%2
2470
11th to 20thNight
39%7%14%22%15%2
2404
21st to endNight
37%5%11%23%20%3
1884
March1st to 10thNight
38%5%12%28%15%3
2111
11th to 20thNight
40%6%9%26%16%3
2090
21st to endNight
52%7%13%19%8%1
2255
April1st to 10thNight
38%7%11%25%17%3
1918
11th to 20thNight
39%6%11%25%17%2
1684
21st to endNight
40%7%13%22%16%1
1620
May1st to 10thNight
41%8%14%22%13%3
1620
11th to 20thNight
38%8%13%24%16%1
1594
21st to endNight
41%8%18%18%12%3
1639
June1st to 10thNight
25%9%15%34%15%3
1440
11th to 20thNight
25%9%15%26%20%5%
1440
21st to endNight
25%6%15%32%19%3
1440
July1st to 10thNight
23%6%16%31%19%4
1502
11th to 20thNight
18%7%19%31%19%6%
1566
21st to endNight
19%6%16%36%20%3
1673
August1st to 10thNight
26%11%17%30%14%1
1601
11th to 20thNight
25%6%14%34%19%3
1600
21st to endNight
25%6%14%25%21%10%
1831
September1st to 10thNight
27%6%12%28%22%6%
1849
11th to 20thNight
25%5%12%36%20%2
1980
21st to endNight
26%5%9%30%26%4
1980
October1st to 10thNight
33%6%11%25%22%2
2108
11th to 20thNight
33%49%23%26%5%
2160
21st to endNight
35%413%22%23%2
2376
November1st to 10thNight
27%5%15%25%24%4
2370
11th to 20thNight
33%5%13%30%17%2
2553
21st to endNight
36%412%29%18%2
2660
December1st to 10thNight
40%6%13%28%12%1
2660
11th to 20thNight
39%5%16%32%8%
3281
21st to endNight
58%5%10%19%7%1
4839

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
20%12%35%23%8%2
270
11th to 20thDay
22%12%36%22%7%1
270
21st to endDay
15%12%43%20%8%2
297
February1st to 10thDay
16%17%45%19%3
270
11th to 20thDay
18%16%38%21%6%1
270
21st to endDay
15%20%40%22%4
225
March1st to 10thDay
18%14%43%20%5%
270
11th to 20thDay
27%11%36%19%7%1
270
21st to endDay
33%17%33%15%21
285
April1st to 10thDay
24%16%37%20%4
302
11th to 20thDay
20%15%36%21%8%
502
21st to endDay
23%16%30%22%8%2
600
May1st to 10thDay
20%13%33%24%8%2
603
11th to 20thDay
18%9%34%25%12%2
625
21st to endDay
20%6%30%27%15%2
679
June1st to 10thDay
7%6%23%35%25%5%
630
11th to 20thDay
9%5%30%36%17%3
630
21st to endDay
9%7%33%34%14%3
630
July1st to 10thDay
11%314%33%30%10%
621
11th to 20thDay
6%427%35%21%7%
618
21st to endDay
7%219%43%26%3
684
August1st to 10thDay
8%219%43%23%4
626
11th to 20thDay
8%5%17%40%27%4
615
21st to endDay
10%221%39%23%5%
644
September1st to 10thDay
13%426%34%19%4
398
11th to 20thDay
7%331%34%20%5%
270
21st to endDay
14%10%33%28%13%1
270
October1st to 10thDay
22%7%29%24%13%6%
270
11th to 20thDay
14%17%41%19%8%1
270
21st to endDay
20%15%35%18%10%2
297
November1st to 10thDay
16%11%36%26%10%1
270
11th to 20thDay
15%14%43%21%7%
270
21st to endDay
22%11%34%23%7%1
270
December1st to 10thDay
9%12%41%31%5%2
270
11th to 20thDay
14%15%33%28%9%1
270
21st to endDay
21%15%40%21%3
297
January1st to 10thNight
12%12%36%32%8%1
950
11th to 20thNight
15%14%35%30%7%
950
21st to endNight
17%9%38%30%6%
1045
February1st to 10thNight
16%11%40%29%4
950
11th to 20thNight
12%11%42%30%5%
929
21st to endNight
14%11%44%25%5%
628
March1st to 10thNight
14%13%39%27%6%1
591
11th to 20thNight
19%8%37%29%7%
570
21st to endNight
22%14%36%23%5%
615
April1st to 10thNight
15%16%41%23%5%
540
11th to 20thNight
15%13%40%28%41
533
21st to endNight
20%11%34%28%7%1
540
May1st to 10thNight
17%11%31%33%8%
540
11th to 20thNight
17%9%31%33%10%1
531
21st to endNight
17%6%30%32%14%1
584
June1st to 10thNight
8%325%47%16%
540
11th to 20thNight
9%332%42%14%1
540
21st to endNight
5%431%46%14%1
540
July1st to 10thNight
6%218%44%28%2
525
11th to 20thNight
4220%50%24%2
522
21st to endNight
4216%54%24%
591
August1st to 10thNight
6%218%48%24%2
537
11th to 20thNight
6%319%47%25%
534
21st to endNight
9%320%42%23%3
594
September1st to 10thNight
9%424%40%21%2
540
11th to 20thNight
11%229%38%18%1
540
21st to endNight
12%434%34%15%1
540
October1st to 10thNight
15%6%34%32%11%2
668
11th to 20thNight
16%11%33%33%7%
720
21st to endNight
18%10%31%31%9%
792
November1st to 10thNight
10%10%34%36%9%1
890
11th to 20thNight
14%12%38%30%7%
950
21st to endNight
16%10%35%29%9%
950
December1st to 10thNight
13%12%38%31%6%
950
11th to 20thNight
17%9%34%33%6%1
950
21st to endNight
20%13%33%29%4
1045
Page generated at 2024-03-24 22:36:58. Version ac07

Copyright © 2024 Attilla Danko.


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