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Sky Pony Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Sky Pony Observatory 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
57%
23904
32%
79120
22%
23809
67%
23809
42%
38519

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
44%
754
46%
3655
20%
736
60%
736
41%
1180
January11th to 20thNight
47%
755
46%
3583
20%
740
62%
740
42%
1163
January21st to endNight
45%
828
26%
3883
20%
814
64%
814
28%
1861
February1st to 10thNight
46%
760
38%
2280
19%
760
66%
760
47%
1092
February11th to 20thNight
44%
743
29%
2218
15%
740
56%
740
41%
1155
February21st to endNight
35%
628
34%
1884
15%
628
54%
628
43%
914
March1st to 10thNight
44%
742
33%
2226
16%
742
59%
742
44%
1103
March11th to 20thNight
43%
720
30%
2026
15%
720
54%
720
39%
1113
March21st to endNight
41%
624
41%
2010
21%
624
62%
624
48%
915
April1st to 10thNight
47%
540
37%
1800
23%
540
65%
540
41%
865
April11th to 20thNight
40%
533
33%
1777
17%
533
60%
533
41%
838
April21st to endNight
46%
540
39%
1800
25%
540
69%
540
52%
766
May1st to 10thNight
50%
540
32%
1800
23%
540
67%
540
47%
818
May11th to 20thNight
55%
531
27%
1770
27%
531
63%
531
40%
902
May21st to endNight
57%
582
26%
1794
22%
582
67%
582
42%
942
June1st to 10thNight
69%
540
25%
1620
23%
540
74%
540
47%
830
June11th to 20thNight
70%
540
28%
1620
26%
540
75%
540
44%
862
June21st to endNight
76%
540
27%
1616
26%
540
78%
540
42%
868
July1st to 10thNight
76%
525
17%
1732
19%
525
76%
525
34%
991
July11th to 20thNight
83%
522
25%
1740
29%
522
84%
522
43%
890
July21st to endNight
82%
591
22%
1859
25%
558
83%
558
39%
986
August1st to 10thNight
84%
537
24%
1779
29%
534
85%
534
42%
906
August11th to 20thNight
83%
534
23%
1778
28%
534
83%
534
34%
998
August21st to endNight
77%
594
19%
1980
22%
594
78%
594
31%
1160
September1st to 10thNight
75%
540
22%
1800
24%
540
75%
540
33%
1028
September11th to 20thNight
74%
540
23%
1895
26%
540
75%
540
29%
1124
September21st to endNight
75%
540
28%
1980
30%
540
77%
540
33%
1053
October1st to 10thNight
72%
540
30%
1980
32%
540
74%
540
39%
976
October11th to 20thNight
63%
675
34%
2115
25%
675
69%
675
44%
1070
October21st to endNight
65%
792
39%
2376
25%
792
73%
792
56%
1096
November1st to 10thNight
66%
763
39%
2243
25%
763
73%
763
57%
1039
November11th to 20thNight
60%
950
35%
2470
19%
950
68%
950
54%
1275
November21st to endNight
50%
950
37%
2470
18%
950
62%
950
48%
1322
December1st to 10thNight
52%
950
37%
2470
19%
950
61%
950
46%
1363
December11th to 20thNight
43%
949
36%
2896
16%
949
57%
949
40%
1517
December21st to endNight
44%
972
27%
4195
19%
963
59%
963
41%
1538

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
4324435%5%6%7%57%
79171
Night
432443446%8%60%
80373
TransparencyDay
22%6%10%17%25%20%
78921
Night
21%6%10%17%26%21%
80145
SeeingDay
7%11%24%30%21%6%
13625
Night
6%7%24%38%23%2
23937

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
3312213446%71%
3167
11th to 20thDay
2212223345%74%
3170
21st to endDay
2424435%5%5%7%59%
3487
February1st to 10thDay
33135%34446%63%
1900
11th to 20thDay
4324334447%62%
1849
21st to endDay
321322345%8%67%
1570
March1st to 10thDay
24245%346%7%8%54%
1850
11th to 20thDay
45%245%35%45%5%58%
1930
21st to endDay
231342445%8%65%
2344
April1st to 10thDay
2324325%45%7%63%
2160
11th to 20thDay
2324424347%66%
2131
21st to endDay
3313223247%71%
2160
May1st to 10thDay
332332235%6%66%
2160
11th to 20thDay
3324435%46%6%60%
2125
21st to endDay
3213325%6%6%8%61%
2474
June1st to 10thDay
2113325%5%8%8%62%
2340
11th to 20thDay
2224435%6%8%9%55%
2340
21st to endDay
5%3245%36%5%7%10%49%
2329
July1st to 10thDay
8%436%7%6%9%8%8%9%32%
2160
11th to 20thDay
6%3246%47%7%9%10%41%
2160
21st to endDay
5%436%7%5%8%7%8%10%37%
2349
August1st to 10thDay
43245%5%8%8%9%12%39%
2149
11th to 20thDay
7%5%38%8%6%7%7%9%11%30%
2123
21st to endDay
7%5%36%7%5%7%7%7%9%37%
2376
September1st to 10thDay
10%5%26%7%46%6%6%8%40%
2160
11th to 20thDay
9%7%37%6%46%6%6%8%38%
2062
21st to endDay
8%5%246%345%5%7%50%
1980
October1st to 10thDay
4424425%46%8%59%
1980
11th to 20thDay
7%324334345%62%
1839
21st to endDay
4313212345%72%
1980
November1st to 10thDay
4312213446%69%
1813
11th to 20thDay
2324424446%67%
1710
21st to endDay
5%42442335%5%63%
1710
December1st to 10thDay
6%5%13433448%58%
1710
11th to 20thDay
23245%445%6%8%58%
2161
21st to endDay
231232346%6%68%
3263
January1st to 10thNight
231332335%6%70%
3788
11th to 20thNight
2212223346%71%
3800
21st to endNight
43245%35%5%6%7%55%
4180
February1st to 10thNight
33143245%5%7%63%
2280
11th to 20thNight
35%15%435%45%7%59%
2218
21st to endNight
331332445%8%64%
1884
March1st to 10thNight
4323326%47%9%56%
2226
11th to 20thNight
4425%5%34445%59%
2026
21st to endNight
3322424446%66%
2010
April1st to 10thNight
432432445%7%61%
1800
11th to 20thNight
342332446%7%62%
1777
21st to endNight
2212323446%72%
1800
May1st to 10thNight
3223424447%65%
1800
11th to 20thNight
4324435%446%59%
1770
21st to endNight
34145%35%5%7%7%56%
1794
June1st to 10thNight
2224435%6%6%10%56%
1620
11th to 20thNight
43235%45%6%7%10%50%
1620
21st to endNight
4325%336%6%7%9%52%
1616
July1st to 10thNight
4335%6%45%7%8%10%46%
1782
11th to 20thNight
4323335%5%8%10%55%
1800
21st to endNight
33245%25%7%8%12%49%
1969
August1st to 10thNight
32135%35%6%10%13%49%
1790
11th to 20thNight
33235%36%7%10%17%41%
1778
21st to endNight
5%425%5%35%6%7%11%46%
1980
September1st to 10thNight
7%4245%45%6%7%9%48%
1800
11th to 20thNight
7%5%25%5%46%6%8%9%44%
1895
21st to endNight
6%5%25%445%6%6%8%50%
1980
October1st to 10thNight
33145%3446%8%58%
1980
11th to 20thNight
7%3244235%46%61%
2115
21st to endNight
3313323345%71%
2376
November1st to 10thNight
4313222346%70%
2243
11th to 20thNight
2324324346%66%
2470
21st to endNight
4424324346%64%
2470
December1st to 10thNight
6%31343446%8%58%
2470
11th to 20thNight
3435%43335%8%59%
3036
21st to endNight
3312224445%71%
4430

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
13%36%14%27%38%
3168
11th to 20thDay
12%35%14%42%23%
3170
21st to endDay
21%5%8%19%32%14%
3487
February1st to 10thDay
19%47%14%24%31%
1900
11th to 20thDay
21%47%15%25%28%
1859
21st to endDay
15%35%13%31%32%
1570
March1st to 10thDay
23%5%8%15%25%23%
1850
11th to 20thDay
24%47%12%23%30%
1930
21st to endDay
17%37%11%31%30%
2344
April1st to 10thDay
18%37%13%28%30%
2160
11th to 20thDay
17%47%11%29%32%
2134
21st to endDay
14%36%12%34%31%
2160
May1st to 10thDay
17%45%11%27%36%
2160
11th to 20thDay
21%6%8%17%25%23%
2128
21st to endDay
16%6%10%18%22%27%
2474
June1st to 10thDay
15%6%14%22%26%17%
2340
11th to 20thDay
19%6%10%19%26%20%
2340
21st to endDay
26%8%11%23%20%13%
2329
July1st to 10thDay
38%13%15%19%11%3
2101
11th to 20thDay
29%11%15%23%18%4
2097
21st to endDay
32%11%20%25%10%1
2219
August1st to 10thDay
27%11%18%28%14%2
2136
11th to 20thDay
41%12%17%19%8%2
2123
21st to endDay
37%11%17%19%12%4
2376
September1st to 10thDay
36%11%13%17%14%9%
2160
11th to 20thDay
36%11%13%16%17%6%
2062
21st to endDay
30%6%10%20%23%11%
1980
October1st to 10thDay
21%6%10%23%21%18%
1980
11th to 20thDay
22%5%7%17%23%25%
1839
21st to endDay
16%25%15%34%28%
1980
November1st to 10thDay
15%5%7%18%29%25%
1813
11th to 20thDay
17%5%8%20%29%21%
1710
21st to endDay
21%47%17%31%20%
1710
December1st to 10thDay
23%48%19%29%16%
1710
11th to 20thDay
21%5%7%17%30%19%
2159
21st to endDay
14%46%14%32%30%
3263
January1st to 10thNight
14%35%12%34%33%
3788
11th to 20thNight
13%37%15%35%27%
3800
21st to endNight
24%6%7%16%34%12%
4180
February1st to 10thNight
18%47%15%25%32%
2280
11th to 20thNight
23%5%8%11%25%28%
2218
21st to endNight
19%45%10%26%36%
1884
March1st to 10thNight
20%49%16%25%26%
2226
11th to 20thNight
25%5%7%11%24%28%
2026
21st to endNight
18%37%13%29%31%
2010
April1st to 10thNight
21%5%7%12%29%27%
1800
11th to 20thNight
19%5%8%13%25%30%
1777
21st to endNight
13%47%15%26%34%
1800
May1st to 10thNight
18%46%12%25%34%
1800
11th to 20thNight
23%7%8%17%22%23%
1771
21st to endNight
23%7%13%19%17%22%
1795
June1st to 10thNight
19%8%14%25%21%13%
1620
11th to 20thNight
24%6%11%20%24%16%
1620
21st to endNight
24%7%15%21%20%13%
1616
July1st to 10thNight
26%11%20%27%12%3
1732
11th to 20thNight
20%8%16%29%22%4
1740
21st to endNight
22%10%22%32%13%1
1859
August1st to 10thNight
19%10%20%32%18%1
1779
11th to 20thNight
24%13%23%27%11%2
1778
21st to endNight
29%11%18%21%15%6%
1980
September1st to 10thNight
30%8%16%20%16%9%
1800
11th to 20thNight
30%12%18%18%15%7%
1895
21st to endNight
27%8%13%20%20%11%
1980
October1st to 10thNight
22%7%14%20%18%18%
1980
11th to 20thNight
23%5%9%18%22%23%
2115
21st to endNight
16%37%12%31%31%
2376
November1st to 10thNight
16%36%15%35%25%
2243
11th to 20thNight
17%46%20%29%24%
2470
21st to endNight
20%47%16%31%21%
2470
December1st to 10thNight
22%5%8%19%26%20%
2470
11th to 20thNight
23%47%17%26%23%
3037
21st to endNight
15%36%15%37%24%
4430

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
9%21%31%29%9%
270
11th to 20thDay
7%20%37%25%11%
270
21st to endDay
5%29%30%27%7%2
297
February1st to 10thDay
9%19%34%24%14%
270
11th to 20thDay
12%20%38%21%8%
270
21st to endDay
9%28%40%19%4
225
March1st to 10thDay
8%18%46%20%9%
255
11th to 20thDay
9%24%40%19%5%2
370
21st to endDay
7%26%44%19%5%
462
April1st to 10thDay
5%20%45%21%7%1
420
11th to 20thDay
7%24%44%19%5%
412
21st to endDay
7%22%40%28%3
420
May1st to 10thDay
6%19%39%27%8%1
423
11th to 20thDay
5%10%35%38%9%2
448
21st to endDay
46%36%40%12%2
622
June1st to 10thDay
2317%47%26%4
630
11th to 20thDay
2215%50%28%3
630
21st to endDay
5%211%35%39%8%
619
July1st to 10thDay
10%16%29%37%17%
446
11th to 20thDay
5%229%47%16%
444
21st to endDay
45%32%45%15%
487
August1st to 10thDay
41423%47%21%
447
11th to 20thDay
7%38%28%40%15%
437
21st to endDay
10%2426%41%17%
495
September1st to 10thDay
10%28%35%35%10%
450
11th to 20thDay
11%29%35%33%11%
352
21st to endDay
10%210%36%31%10%
270
October1st to 10thDay
12%316%34%30%5%
270
11th to 20thDay
8%6%24%40%18%4
270
21st to endDay
7%13%27%26%19%7%
297
November1st to 10thDay
9%9%28%34%16%4
270
11th to 20thDay
6%12%27%33%17%6%
270
21st to endDay
13%20%30%21%12%3
270
December1st to 10thDay
11%14%27%31%13%3
270
11th to 20thDay
8%20%36%28%8%
270
21st to endDay
7%22%36%27%8%
297
January1st to 10thNight
6%10%34%35%13%2
760
11th to 20thNight
7%10%32%34%15%1
760
21st to endNight
6%12%33%35%13%1
836
February1st to 10thNight
6%14%30%33%15%2
760
11th to 20thNight
7%10%36%38%9%
744
21st to endNight
8%15%40%34%4
628
March1st to 10thNight
6%12%34%35%12%1
742
11th to 20thNight
7%13%32%32%15%1
720
21st to endNight
5%12%40%36%8%1
624
April1st to 10thNight
6%11%32%41%10%
540
11th to 20thNight
6%13%39%35%7%
533
21st to endNight
212%36%40%9%1
540
May1st to 10thNight
48%35%41%12%1
540
11th to 20thNight
6%6%28%47%12%1
531
21st to endNight
45%27%47%16%1
584
June1st to 10thNight
2219%54%22%1
540
11th to 20thNight
4117%53%23%1
540
21st to endNight
4211%51%31%1
540
July1st to 10thNight
5%16%38%47%3
525
11th to 20thNight
4441%47%4
522
21st to endNight
3442%47%4
591
August1st to 10thNight
31229%59%7%
537
11th to 20thNight
41327%57%9%
534
21st to endNight
6%1430%54%5%
594
September1st to 10thNight
8%2430%50%6%
540
11th to 20thNight
10%16%39%41%4
540
21st to endNight
8%19%39%37%5%
540
October1st to 10thNight
6%213%45%31%3
540
11th to 20thNight
8%5%19%40%25%3
675
21st to endNight
46%20%37%25%7%
792
November1st to 10thNight
6%322%38%26%5%
763
11th to 20thNight
47%23%42%22%2
950
21st to endNight
8%11%26%36%17%3
950
December1st to 10thNight
8%8%28%36%17%2
950
11th to 20thNight
6%11%35%36%12%1
950
21st to endNight
5%14%32%36%12%2
982
Page generated at 2024-03-03 05:28:59. Version ac07

Copyright © 2024 Attilla Danko.


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