Cosmic Campground
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cosmic Campground clear sky chart from 2005-11-06 to 2024-02-20.

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
63%
23728
32%
79363
24%
23630
72%
23630
43%
38977

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
55%
757
32%
4019
25%
736
69%
736
28%
1880
January11th to 20thNight
51%
753
41%
3913
27%
740
65%
740
37%
1403
January21st to endNight
49%
828
22%
4331
24%
814
66%
814
22%
2405
February1st to 10thNight
53%
760
33%
2470
24%
760
67%
760
44%
1205
February11th to 20thNight
44%
739
31%
2309
21%
738
59%
738
41%
1193
February21st to endNight
41%
592
38%
1628
20%
592
58%
592
46%
875
March1st to 10thNight
47%
720
37%
1980
21%
720
62%
720
48%
1016
March11th to 20thNight
56%
720
36%
1980
21%
720
68%
720
51%
1015
March21st to endNight
52%
792
36%
2178
19%
792
65%
792
50%
1103
April1st to 10thNight
54%
630
37%
1890
21%
630
70%
630
57%
839
April11th to 20thNight
51%
533
38%
1777
24%
533
70%
533
49%
741
April21st to endNight
53%
540
43%
1800
27%
540
75%
540
60%
703
May1st to 10thNight
63%
540
36%
1747
28%
540
76%
540
58%
731
May11th to 20thNight
65%
531
34%
1594
26%
531
73%
531
55%
735
May21st to endNight
68%
583
38%
1746
28%
582
77%
582
66%
716
June1st to 10thNight
74%
540
32%
1620
29%
540
76%
540
55%
751
June11th to 20thNight
76%
540
34%
1620
28%
540
79%
540
66%
687
June21st to endNight
76%
540
22%
1620
20%
540
77%
540
44%
853
July1st to 10thNight
77%
525
20%
1575
18%
525
77%
525
36%
891
July11th to 20thNight
75%
522
13%
1566
13%
522
75%
522
27%
1001
July21st to endNight
74%
591
12%
1674
11%
558
73%
558
24%
1106
August1st to 10thNight
82%
537
15%
1602
14%
534
82%
534
33%
960
August11th to 20thNight
75%
534
21%
1704
22%
534
75%
534
27%
1064
August21st to endNight
79%
594
22%
1980
25%
594
79%
594
30%
1170
September1st to 10thNight
75%
540
27%
1800
30%
540
75%
540
31%
1045
September11th to 20thNight
79%
688
34%
1948
29%
688
81%
688
46%
1056
September21st to endNight
78%
720
35%
1992
25%
720
83%
720
59%
978
October1st to 10thNight
69%
720
33%
2160
25%
720
75%
720
50%
1064
October11th to 20thNight
72%
720
42%
2160
31%
720
80%
720
65%
928
October21st to endNight
71%
792
44%
2376
31%
792
80%
792
65%
1028
November1st to 10thNight
71%
740
44%
2220
32%
740
81%
740
64%
946
November11th to 20thNight
67%
760
42%
2280
30%
760
77%
760
61%
1009
November21st to endNight
57%
760
38%
2375
27%
760
69%
760
44%
1187
December1st to 10thNight
58%
760
37%
2470
30%
760
68%
760
45%
1210
December11th to 20thNight
50%
758
31%
2931
24%
758
63%
758
31%
1575
December21st to endNight
48%
829
22%
4328
23%
817
62%
817
27%
1908

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
442443445%7%59%
78926
Night
442342445%7%62%
80337
TransparencyDay
24%5%8%15%27%21%
78652
Night
22%5%8%17%29%19%
80132
SeeingDay
9%15%29%28%16%4
13585
Night
6%5%21%39%25%4
23759

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
39%24423445%60%
2858
11th to 20thDay
35%1232445%6%64%
2860
21st to endDay
7%8%244245%5%6%54%
3146
February1st to 10thDay
36%25%323435%65%
1710
11th to 20thDay
5%6%24324345%61%
1740
21st to endDay
47%2332435%5%63%
1628
March1st to 10thDay
44233245%5%9%59%
1980
11th to 20thDay
4423323346%64%
1980
21st to endDay
322332435%7%66%
2178
April1st to 10thDay
221332335%7%69%
2070
11th to 20thDay
2223322345%71%
2131
21st to endDay
2213322346%72%
2160
May1st to 10thDay
1213224446%71%
2208
11th to 20thDay
221333345%7%67%
2301
21st to endDay
211222334477%
2530
June1st to 10thDay
121332345%7%70%
2340
11th to 20thDay
1113313346%74%
2340
21st to endDay
33235%36%6%7%8%53%
2340
July1st to 10thDay
5%326%8%5%6%7%6%9%42%
2340
11th to 20thDay
5%437%8%5%8%9%9%11%30%
2340
21st to endDay
6%5%37%8%6%9%7%9%11%28%
2545
August1st to 10thDay
5%437%8%5%8%9%7%9%36%
2328
11th to 20thDay
6%5%36%8%5%7%7%8%8%36%
2195
21st to endDay
5%426%6%5%7%7%7%10%42%
2376
September1st to 10thDay
7%5%25%7%36%6%7%8%45%
2160
11th to 20thDay
5%3245%35%36%7%59%
2008
21st to endDay
4323423447%63%
1967
October1st to 10thDay
5%224334446%63%
1800
11th to 20thDay
411222433475%
1800
21st to endDay
2212212336%77%
1980
November1st to 10thDay
2212222237%74%
1859
11th to 20thDay
211332245%5%71%
1900
21st to endDay
5%424424446%63%
1803
December1st to 10thDay
6%5%13323347%63%
1710
11th to 20thDay
6%7%36%5%33447%53%
2169
21st to endDay
5%5%245%34445%58%
3146
January1st to 10thNight
47%35%424447%55%
4097
11th to 20thNight
431242333472%
4110
21st to endNight
8%11%3442446%6%47%
4521
February1st to 10thNight
46%22324346%65%
2470
11th to 20thNight
6%6%23324345%62%
2308
21st to endNight
46%1333435%5%64%
1628
March1st to 10thNight
331342335%7%66%
1980
11th to 20thNight
5%412222436%67%
1980
21st to endNight
3424323246%68%
2178
April1st to 10thNight
211221445%8%70%
1890
11th to 20thNight
2212323345%72%
1777
21st to endNight
2211212235%79%
1800
May1st to 10thNight
1212222346%74%
1747
11th to 20thNight
421321335%6%69%
1594
21st to endNight
211212235%80%
1746
June1st to 10thNight
2213324347%68%
1620
11th to 20thNight
2212222346%76%
1620
21st to endNight
22245%35%5%7%8%58%
1620
July1st to 10thNight
2425%6%45%7%9%12%44%
1620
11th to 20thNight
2427%7%48%8%9%12%37%
1620
21st to endNight
35%36%6%5%7%9%10%14%32%
1773
August1st to 10thNight
22146%46%7%9%10%47%
1611
11th to 20thNight
4436%5%47%9%8%10%41%
1704
21st to endNight
4325%7%46%6%8%11%43%
1980
September1st to 10thNight
5%5%26%6%46%5%6%9%47%
1800
11th to 20thNight
5%3245%3445%6%60%
1948
21st to endNight
3213323446%69%
1992
October1st to 10thNight
32135%2445%5%66%
2160
11th to 20thNight
321221223478%
2160
21st to endNight
211222233479%
2376
November1st to 10thNight
321121235%6%75%
2220
11th to 20thNight
2212312446%74%
2280
21st to endNight
7%413323346%64%
2375
December1st to 10thNight
6%5%13323446%64%
2470
11th to 20thNight
6%6%25%5%3445%7%53%
3041
21st to endNight
6%6%14424446%59%
4521

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
27%35%14%37%14%
2859
11th to 20thDay
21%47%26%28%14%
2860
21st to endDay
31%46%19%29%10%
3146
February1st to 10thDay
24%37%15%27%24%
1710
11th to 20thDay
27%36%15%29%21%
1749
21st to endDay
25%3415%31%24%
1628
March1st to 10thDay
23%36%14%33%21%
1980
11th to 20thDay
21%36%12%35%23%
1980
21st to endDay
18%35%16%39%18%
2178
April1st to 10thDay
16%35%14%38%24%
2070
11th to 20thDay
16%25%12%33%32%
2134
21st to endDay
14%2416%38%26%
2160
May1st to 10thDay
15%35%13%32%32%
2208
11th to 20thDay
17%47%13%30%28%
2304
21st to endDay
13%2411%32%38%
2530
June1st to 10thDay
14%46%9%33%35%
2340
11th to 20thDay
12%247%23%51%
2340
21st to endDay
25%6%9%11%21%27%
2340
July1st to 10thDay
34%9%11%15%12%17%
2276
11th to 20thDay
39%14%17%18%8%4
2271
21st to endDay
42%14%22%14%6%2
2404
August1st to 10thDay
38%11%16%14%14%6%
2313
11th to 20thDay
39%11%16%16%14%6%
2195
21st to endDay
33%10%15%19%19%5%
2376
September1st to 10thDay
33%7%13%19%17%12%
2160
11th to 20thDay
23%6%8%13%31%18%
2008
21st to endDay
19%5%7%18%31%21%
1967
October1st to 10thDay
21%5%8%16%26%24%
1800
11th to 20thDay
14%3311%32%37%
1800
21st to endDay
13%2416%37%28%
1980
November1st to 10thDay
13%25%22%33%26%
1859
11th to 20thDay
15%46%16%34%26%
1900
21st to endDay
23%46%15%31%20%
1803
December1st to 10thDay
23%36%19%31%19%
1710
11th to 20thDay
33%47%20%23%13%
2168
21st to endDay
28%37%15%30%16%
3146
January1st to 10thNight
28%5%7%15%34%11%
4097
11th to 20thNight
17%37%22%39%11%
4110
21st to endNight
36%5%7%18%27%8%
4521
February1st to 10thNight
23%38%16%30%21%
2470
11th to 20thNight
26%35%17%30%19%
2309
21st to endNight
23%35%15%29%24%
1628
March1st to 10thNight
20%46%16%35%20%
1980
11th to 20thNight
20%36%13%37%21%
1980
21st to endNight
20%36%19%36%16%
2178
April1st to 10thNight
13%36%18%40%20%
1890
11th to 20thNight
15%25%12%37%28%
1777
21st to endNight
10%35%18%40%24%
1800
May1st to 10thNight
12%35%15%33%31%
1747
11th to 20thNight
16%48%14%33%26%
1595
21st to endNight
9%35%11%33%39%
1746
June1st to 10thNight
16%35%10%30%35%
1620
11th to 20thNight
11%36%8%24%49%
1620
21st to endNight
22%7%10%11%20%29%
1620
July1st to 10thNight
27%9%16%18%12%18%
1575
11th to 20thNight
32%14%21%19%9%4
1566
21st to endNight
36%14%27%16%6%2
1674
August1st to 10thNight
26%14%21%18%14%7%
1602
11th to 20thNight
33%12%18%16%15%6%
1704
21st to endNight
30%11%18%22%15%4
1980
September1st to 10thNight
32%7%12%18%19%12%
1800
11th to 20thNight
23%6%9%16%29%16%
1948
21st to endNight
16%48%17%34%21%
1992
October1st to 10thNight
19%5%9%17%27%24%
2160
11th to 20thNight
12%3414%33%36%
2160
21st to endNight
11%35%19%34%29%
2376
November1st to 10thNight
11%35%19%39%23%
2220
11th to 20thNight
13%36%20%30%28%
2280
21st to endNight
22%4417%33%19%
2375
December1st to 10thNight
24%26%20%29%19%
2470
11th to 20thNight
31%48%18%27%12%
3041
21st to endNight
26%48%16%25%21%
4521

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%11%36%26%11%1
270
11th to 20thDay
14%13%31%27%12%2
270
21st to endDay
8%18%30%30%12%3
297
February1st to 10thDay
9%18%33%29%9%3
270
11th to 20thDay
17%23%36%20%4
295
21st to endDay
22%29%30%15%21
346
March1st to 10thDay
14%31%35%15%5%1
420
11th to 20thDay
16%23%33%21%6%2
420
21st to endDay
16%33%29%16%5%1
462
April1st to 10thDay
8%30%35%20%6%1
420
11th to 20thDay
14%30%36%15%41
412
21st to endDay
14%23%39%17%6%1
420
May1st to 10thDay
8%23%43%18%7%1
423
11th to 20thDay
418%42%22%11%3
448
21st to endDay
6%21%40%24%8%1
485
June1st to 10thDay
311%42%28%14%3
450
11th to 20thDay
411%38%30%14%3
450
21st to endDay
38%36%32%16%5%
450
July1st to 10thDay
7%318%36%29%6%
446
11th to 20thDay
6%27%31%41%12%
444
21st to endDay
7%28%30%41%12%
487
August1st to 10thDay
4210%42%31%11%
447
11th to 20thDay
7%414%38%29%9%
437
21st to endDay
6%212%40%32%9%
495
September1st to 10thDay
8%5%19%40%22%6%
450
11th to 20thDay
45%30%40%18%3
450
21st to endDay
5%12%28%35%17%3
437
October1st to 10thDay
5%13%25%32%21%4
270
11th to 20thDay
8%9%24%37%17%4
270
21st to endDay
6%13%25%31%21%4
297
November1st to 10thDay
6%13%34%31%13%2
270
11th to 20thDay
5%10%26%38%18%3
270
21st to endDay
10%18%31%29%10%2
270
December1st to 10thDay
14%13%27%30%14%1
270
11th to 20thDay
8%19%29%31%12%1
270
21st to endDay
18%21%30%25%6%1
297
January1st to 10thNight
8%6%28%38%16%4
760
11th to 20thNight
8%7%29%39%14%3
760
21st to endNight
10%6%30%35%16%3
836
February1st to 10thNight
8%8%28%38%15%3
760
11th to 20thNight
10%7%35%38%10%1
742
21st to endNight
9%9%38%33%10%1
592
March1st to 10thNight
6%11%32%37%13%
720
11th to 20thNight
8%8%25%38%18%3
720
21st to endNight
7%9%28%41%14%2
792
April1st to 10thNight
48%31%44%13%1
630
11th to 20thNight
6%13%27%42%13%1
533
21st to endNight
49%32%37%17%1
540
May1st to 10thNight
17%25%47%18%1
540
11th to 20thNight
4422%47%22%1
531
21st to endNight
35%21%51%18%2
584
June1st to 10thNight
3215%51%26%2
540
11th to 20thNight
2315%50%29%1
540
21st to endNight
2110%44%40%4
540
July1st to 10thNight
415%36%48%7%
525
11th to 20thNight
3423%59%11%
522
21st to endNight
5%15%21%57%11%
591
August1st to 10thNight
21121%60%14%
537
11th to 20thNight
5%2428%52%9%
534
21st to endNight
5%1429%53%8%
594
September1st to 10thNight
7%17%38%42%5%
540
11th to 20thNight
5%16%42%40%6%
688
21st to endNight
4113%45%33%4
720
October1st to 10thNight
3417%48%25%2
720
11th to 20thNight
3219%48%25%3
720
21st to endNight
4320%41%27%6%
792
November1st to 10thNight
4418%45%25%4
740
11th to 20thNight
2325%43%24%3
760
21st to endNight
9%7%24%34%23%3
760
December1st to 10thNight
11%423%44%16%3
760
11th to 20thNight
12%6%28%40%13%2
760
21st to endNight
11%8%29%39%11%2
836
Page generated at 2024-02-17 04:28:36. Version ac07

Copyright 2024 Attilla Danko


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