Rosebud
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Rosebud clear sky chart from 2005-11-06 to 2024-03-01.

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
35%
24607
20%
80358
12%
24498
44%
24498
23%
51709

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
18%
941
15%
4335
5%
926
29%
926
11%
2962
January11th to 20thNight
18%
950
16%
4050
6%
930
28%
930
11%
2962
January21st to endNight
17%
1039
13%
4480
4%
1023
27%
1023
12%
3313
February1st to 10thNight
17%
950
16%
2470
3%
950
25%
950
19%
1803
February11th to 20thNight
17%
814
18%
2290
5%
811
26%
811
20%
1528
February21st to endNight
15%
628
19%
1884
5%
628
27%
628
19%
1251
March1st to 10thNight
19%
643
20%
2087
7%
643
31%
643
20%
1362
March11th to 20thNight
23%
540
18%
1980
10%
540
35%
540
17%
1320
March21st to endNight
18%
594
11%
2109
5%
594
26%
594
12%
1527
April1st to 10thNight
26%
540
22%
1800
11%
540
42%
540
26%
1054
April11th to 20thNight
27%
533
22%
1775
14%
533
41%
533
23%
1097
April21st to endNight
24%
540
19%
1800
9%
540
38%
540
20%
1167
May1st to 10thNight
33%
540
16%
1760
10%
540
42%
540
23%
1105
May11th to 20thNight
41%
531
19%
1445
14%
531
45%
531
28%
954
May21st to endNight
47%
584
18%
1551
10%
582
53%
582
27%
1047
June1st to 10thNight
61%
540
19%
1440
15%
540
64%
540
37%
879
June11th to 20thNight
57%
540
25%
1440
16%
540
62%
540
42%
844
June21st to endNight
61%
540
26%
1440
16%
540
66%
540
47%
802
July1st to 10thNight
70%
525
19%
1400
15%
525
72%
525
38%
854
July11th to 20thNight
67%
522
23%
1425
18%
522
70%
522
46%
786
July21st to endNight
68%
591
23%
1673
22%
558
73%
558
37%
963
August1st to 10thNight
70%
537
23%
1601
25%
534
72%
534
37%
907
August11th to 20thNight
69%
534
24%
1733
28%
534
72%
534
38%
936
August21st to endNight
70%
594
25%
1980
28%
594
73%
594
38%
1050
September1st to 10thNight
61%
540
25%
1800
25%
540
65%
540
33%
1001
September11th to 20thNight
63%
540
33%
1800
31%
540
69%
540
34%
994
September21st to endNight
54%
681
30%
2017
21%
681
61%
681
37%
1137
October1st to 10thNight
51%
720
28%
2160
20%
720
57%
720
41%
1162
October11th to 20thNight
32%
720
29%
2160
14%
720
47%
720
31%
1276
October21st to endNight
27%
792
24%
2376
11%
792
39%
792
25%
1488
November1st to 10thNight
32%
740
28%
2353
15%
740
48%
740
32%
1313
November11th to 20thNight
29%
760
27%
2470
14%
760
45%
760
26%
1458
November21st to endNight
24%
883
21%
2593
9%
883
36%
883
24%
1676
December1st to 10thNight
22%
950
18%
2660
7%
950
33%
950
21%
1823
December11th to 20thNight
24%
949
19%
3157
8%
948
33%
948
19%
2095
December21st to endNight
16%
1042
10%
4864
5%
1026
28%
1026
8%
3813

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
13%7%35%5%3445%7%42%
78571
Night
13%8%36%5%34446%43%
80878
TransparencyDay
41%7%12%23%15%3
78283
Night
41%6%11%23%16%3
80686
SeeingDay
17%13%28%25%14%3
14596
Night
17%13%30%27%12%1
24626

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
11%13%6%9%5%3446%6%34%
2555
11th to 20thDay
12%11%5%7%6%4445%6%37%
2850
21st to endDay
19%13%6%6%433446%32%
3135
February1st to 10thDay
14%12%6%8%6%35%45%6%34%
1710
11th to 20thDay
15%9%45%5%35%446%39%
1776
21st to endDay
14%11%37%5%34446%39%
1570
March1st to 10thDay
14%9%46%5%34447%41%
1894
11th to 20thDay
19%10%47%6%33446%35%
1980
21st to endDay
20%13%5%7%6%3445%6%29%
2245
April1st to 10thDay
11%6%36%5%35%5%5%8%44%
2160
11th to 20thDay
18%8%25%5%34445%40%
2134
21st to endDay
20%7%36%6%3445%6%35%
2160
May1st to 10thDay
19%6%36%445%5%5%8%35%
2196
11th to 20thDay
16%6%25%5%35%5%6%8%40%
2447
21st to endDay
11%6%46%7%46%6%7%8%37%
2725
June1st to 10thDay
9%425%5%35%6%7%8%45%
2520
11th to 20thDay
9%425%5%345%6%10%49%
2520
21st to endDay
5%3245%35%6%8%10%49%
2520
July1st to 10thDay
10%4245%36%6%8%10%43%
2520
11th to 20thDay
5%323435%6%7%10%52%
2483
21st to endDay
9%425%5%46%6%6%9%43%
2546
August1st to 10thDay
8%425%6%46%7%8%9%42%
2328
11th to 20thDay
9%5%36%6%46%6%7%9%41%
2166
21st to endDay
9%5%244345%5%8%51%
2376
September1st to 10thDay
13%5%1343446%8%48%
2160
11th to 20thDay
10%5%25%42445%8%51%
2160
21st to endDay
8%4245%35%45%7%54%
1919
October1st to 10thDay
11%435%5%23347%54%
1800
11th to 20thDay
15%6%34323345%52%
1800
21st to endDay
17%9%34423335%46%
1980
November1st to 10thDay
11%6%23434446%54%
1723
11th to 20thDay
14%7%25%5%3345%7%47%
1710
21st to endDay
15%10%45%323445%45%
1582
December1st to 10thDay
15%11%36%433346%42%
1520
11th to 20thDay
13%11%46%5%33346%41%
1918
21st to endDay
15%16%6%10%6%34446%27%
2783
January1st to 10thNight
13%10%7%9%6%34445%36%
4396
11th to 20thNight
13%9%49%9%48%44431%
4120
21st to endNight
23%14%6%6%43333431%
4532
February1st to 10thNight
15%10%5%8%5%35%45%6%35%
2470
11th to 20thNight
14%8%5%6%6%2445%6%41%
2289
21st to endNight
15%11%37%5%34346%39%
1884
March1st to 10thNight
16%10%35%5%24345%43%
2087
11th to 20thNight
18%9%47%5%3445%5%37%
1980
21st to endNight
20%10%46%5%45%5%5%6%29%
2109
April1st to 10thNight
12%6%36%42345%7%49%
1800
11th to 20thNight
14%9%34424347%45%
1775
21st to endNight
19%6%36%5%3445%6%40%
1800
May1st to 10thNight
15%6%26%4345%48%44%
1760
11th to 20thNight
15%7%345%34447%44%
1444
21st to endNight
9%7%36%5%45%5%6%8%42%
1551
June1st to 10thNight
8%4245%345%6%9%51%
1440
11th to 20thNight
7%4244345%411%53%
1440
21st to endNight
33145%245%5%10%57%
1440
July1st to 10thNight
9%2244345%7%9%50%
1440
11th to 20thNight
44244335%6%10%56%
1473
21st to endNight
5%5%246%35%5%6%10%50%
1772
August1st to 10thNight
6%3144345%7%10%53%
1611
11th to 20thNight
6%4245%3447%9%54%
1733
21st to endNight
6%32442446%8%56%
1980
September1st to 10thNight
13%5%24323346%54%
1800
11th to 20thNight
9%425%434448%52%
1800
21st to endNight
8%42443435%5%58%
2017
October1st to 10thNight
9%423423348%58%
2160
11th to 20thNight
14%5%25%32335%6%51%
2160
21st to endNight
20%6%14423335%49%
2376
November1st to 10thNight
10%6%24323345%57%
2353
11th to 20thNight
14%6%35%423346%49%
2470
21st to endNight
17%9%35%423336%45%
2593
December1st to 10thNight
15%10%46%5%3446%7%37%
2660
11th to 20thNight
15%10%5%6%5%34346%40%
3279
21st to endNight
16%19%6%9%6%35%43424%
4884

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
49%7%10%23%10%1
2556
11th to 20thDay
46%5%11%24%14%
2850
21st to endDay
54%49%16%14%2
3135
February1st to 10thDay
52%410%21%11%1
1710
11th to 20thDay
47%5%11%19%14%4
1785
21st to endDay
46%5%8%22%14%5%
1570
March1st to 10thDay
45%5%9%22%15%4
1894
11th to 20thDay
53%5%9%18%13%3
1980
21st to endDay
57%6%10%16%9%1
2245
April1st to 10thDay
38%6%12%24%19%1
2160
11th to 20thDay
46%411%22%15%3
2134
21st to endDay
49%6%12%19%12%1
2160
May1st to 10thDay
46%8%14%21%11%1
2196
11th to 20thDay
41%8%13%22%14%2
2451
21st to endDay
43%10%14%19%13%2
2725
June1st to 10thDay
33%10%14%27%15%2
2520
11th to 20thDay
30%7%14%27%19%3
2520
21st to endDay
28%9%17%26%15%5%
2520
July1st to 10thDay
33%10%17%25%11%4
2451
11th to 20thDay
25%9%17%27%18%3
2408
21st to endDay
35%9%13%29%12%1
2405
August1st to 10thDay
34%11%16%24%14%1
2314
11th to 20thDay
38%8%13%25%15%1
2166
21st to endDay
31%7%14%24%19%5%
2376
September1st to 10thDay
32%8%12%27%17%4
2160
11th to 20thDay
33%5%9%26%26%2
2160
21st to endDay
30%6%10%27%24%3
1919
October1st to 10thDay
32%5%10%25%25%4
1800
11th to 20thDay
35%49%25%22%5%
1800
21st to endDay
41%49%26%17%4
1980
November1st to 10thDay
32%412%24%22%5%
1723
11th to 20thDay
37%5%10%22%22%5%
1710
21st to endDay
43%5%8%27%17%1
1582
December1st to 10thDay
44%5%10%28%11%1
1520
11th to 20thDay
46%411%20%18%2
1915
21st to endDay
58%7%10%14%10%1
2783
January1st to 10thNight
52%5%10%22%11%1
4396
11th to 20thNight
56%6%8%20%9%1
4120
21st to endNight
58%49%21%7%1
4532
February1st to 10thNight
50%5%10%19%13%2
2470
11th to 20thNight
44%410%22%16%3
2290
21st to endNight
46%411%21%14%4
1884
March1st to 10thNight
45%5%8%21%17%5%
2087
11th to 20thNight
49%5%9%22%12%3
1980
21st to endNight
54%8%11%18%8%1
2109
April1st to 10thNight
35%5%12%26%19%3
1800
11th to 20thNight
39%6%10%24%16%5%
1775
21st to endNight
45%5%9%23%17%1
1800
May1st to 10thNight
40%7%14%21%17%2
1760
11th to 20thNight
40%7%13%22%16%2
1445
21st to endNight
38%10%15%19%15%3
1552
June1st to 10thNight
30%8%15%28%17%3
1440
11th to 20thNight
25%8%13%26%23%4
1440
21st to endNight
20%8%16%30%18%7%
1440
July1st to 10thNight
29%9%16%28%15%4
1400
11th to 20thNight
22%7%16%28%23%3
1425
21st to endNight
27%9%13%32%18%1
1673
August1st to 10thNight
25%10%16%33%14%2
1601
11th to 20thNight
26%8%15%30%20%2
1733
21st to endNight
25%8%15%24%22%6%
1980
September1st to 10thNight
32%5%11%26%21%5%
1800
11th to 20thNight
30%6%10%23%27%3
1800
21st to endNight
28%6%9%25%28%4
2017
October1st to 10thNight
26%5%12%26%27%5%
2160
11th to 20thNight
34%48%28%20%6%
2160
21st to endNight
40%49%22%21%4
2376
November1st to 10thNight
30%5%12%26%21%6%
2353
11th to 20thNight
36%48%24%23%4
2470
21st to endNight
43%410%25%17%2
2593
December1st to 10thNight
46%5%10%24%13%2
2660
11th to 20thNight
46%5%10%24%15%1
3281
21st to endNight
62%7%9%13%7%2
4884

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
27%24%31%14%3
270
11th to 20thDay
31%24%36%9%
270
21st to endDay
17%31%38%12%2
297
February1st to 10thDay
26%26%33%13%1
270
11th to 20thDay
28%27%31%11%21
270
21st to endDay
31%24%36%8%1
225
March1st to 10thDay
23%30%39%7%1
240
11th to 20thDay
34%20%31%12%11
240
21st to endDay
37%23%26%14%1
331
April1st to 10thDay
19%18%40%17%5%1
420
11th to 20thDay
26%19%31%17%6%
412
21st to endDay
26%16%35%18%5%1
420
May1st to 10thDay
22%17%35%20%5%1
459
11th to 20thDay
18%17%28%25%10%2
625
21st to endDay
14%9%34%25%14%4
679
June1st to 10thDay
10%5%24%34%21%5%
630
11th to 20thDay
9%5%28%35%20%3
630
21st to endDay
5%8%33%35%15%3
630
July1st to 10thDay
12%215%31%30%9%
621
11th to 20thDay
6%5%23%37%25%5%
618
21st to endDay
9%319%36%27%6%
684
August1st to 10thDay
9%317%41%24%6%
626
11th to 20thDay
10%420%34%25%6%
480
21st to endDay
10%220%30%31%7%
495
September1st to 10thDay
13%419%33%24%7%
450
11th to 20thDay
9%320%32%24%12%
450
21st to endDay
10%9%23%34%18%6%
370
October1st to 10thDay
14%13%32%27%11%2
270
11th to 20thDay
21%21%32%21%4
270
21st to endDay
32%24%26%16%2
297
November1st to 10thDay
16%14%41%18%9%3
270
11th to 20thDay
21%22%31%19%6%1
270
21st to endDay
26%20%30%21%31
270
December1st to 10thDay
18%27%30%15%7%3
270
11th to 20thDay
25%19%37%15%3
270
21st to endDay
25%26%35%11%3
297
January1st to 10thNight
21%21%35%19%4
950
11th to 20thNight
24%23%33%18%3
950
21st to endNight
21%19%39%20%1
1045
February1st to 10thNight
24%18%38%17%2
950
11th to 20thNight
21%20%38%18%2
814
21st to endNight
25%22%36%16%2
628
March1st to 10thNight
23%19%37%19%3
643
11th to 20thNight
24%14%37%21%4
540
21st to endNight
25%18%34%19%3
594
April1st to 10thNight
16%18%38%24%4
540
11th to 20thNight
20%15%35%26%5%
533
21st to endNight
23%14%36%21%6%
540
May1st to 10thNight
17%11%33%29%9%
540
11th to 20thNight
18%8%28%32%13%1
531
21st to endNight
12%7%29%32%19%3
584
June1st to 10thNight
10%320%42%24%2
540
11th to 20thNight
7%426%41%20%1
540
21st to endNight
5%325%46%19%2
540
July1st to 10thNight
10%211%40%31%6%
525
11th to 20thNight
3320%40%31%3
522
21st to endNight
7%117%44%29%2
591
August1st to 10thNight
7%114%44%32%1
537
11th to 20thNight
7%216%40%32%3
534
21st to endNight
7%216%39%34%3
594
September1st to 10thNight
15%315%37%26%4
540
11th to 20thNight
11%415%38%28%5%
540
21st to endNight
10%6%25%32%23%4
681
October1st to 10thNight
11%6%29%30%22%3
720
11th to 20thNight
17%14%34%25%9%1
720
21st to endNight
24%14%33%22%7%
792
November1st to 10thNight
14%12%39%26%9%
740
11th to 20thNight
19%17%33%24%7%
760
21st to endNight
22%16%35%21%5%
883
December1st to 10thNight
23%18%35%20%5%1
950
11th to 20thNight
25%14%34%24%3
950
21st to endNight
26%19%35%18%2
1045
Page generated at 2024-02-27 05:30:17. Version ac07

Copyright © 2024 Attilla Danko.


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