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Majestic Skies Ranch
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Majestic Skies Ranch clear sky chart from 2005-11-05 to 2020-06-03.

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
55%
19235
33%
57887
21%
19192
67%
19192
47%
28796

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 15thNight
50%
898
33%
2912
22%
896
64%
896
47%
1376
January16th to endNight
45%
960
38%
3120
23%
960
64%
960
48%
1446
February1st to 15thNight
47%
883
35%
2730
21%
880
63%
880
50%
1284
February16th to endNight
34%
792
39%
2374
15%
792
59%
792
49%
1138
March1st to 15thNight
43%
900
36%
2543
17%
900
59%
900
48%
1275
March16th to endNight
45%
896
39%
2576
17%
896
64%
896
52%
1223
April1st to 15thNight
36%
674
36%
2248
15%
674
60%
674
46%
1006
April16th to endNight
39%
669
40%
2229
20%
669
67%
669
51%
944
May1st to 15thNight
47%
675
28%
2249
21%
674
61%
674
47%
1039
May16th to endNight
57%
706
34%
2091
22%
705
70%
705
54%
989
June1st to 15thNight
62%
637
30%
1699
21%
637
68%
637
53%
891
June16th to endNight
72%
630
25%
1680
20%
630
74%
630
48%
917
July1st to 15thNight
74%
600
20%
1768
19%
600
74%
600
36%
1042
July16th to endNight
80%
660
19%
1881
18%
627
80%
627
35%
1094
August1st to 15thNight
82%
620
18%
2018
21%
617
82%
617
32%
1181
August16th to endNight
82%
669
23%
2230
26%
669
83%
669
36%
1220
September1st to 15thNight
71%
630
27%
2100
29%
630
74%
630
32%
1207
September16th to endNight
72%
637
36%
2240
31%
637
81%
637
46%
1033
October1st to 15thNight
60%
840
33%
2520
21%
840
68%
840
48%
1260
October16th to endNight
62%
896
40%
2688
23%
896
74%
896
59%
1201
November1st to 15thNight
59%
941
40%
2701
22%
941
70%
941
64%
1189
November16th to endNight
55%
1125
38%
2925
20%
1125
65%
1125
54%
1500
December1st to 15thNight
49%
1125
35%
3033
19%
1125
60%
1125
51%
1566
December16th to endNight
41%
1172
32%
3332
18%
1172
54%
1172
44%
1775

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
331332345%7%61%
58502
Night
321232345%7%63%
58084
TransparencyDay
21%5%9%18%27%17%
58198
Night
19%5%9%19%28%17%
57890
SeeingDay
6%10%25%30%20%6%
8952
Night
46%28%36%20%2
19239

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 15thDay
231222235%7%65%
2016
16th to endDay
4312212345%67%
2160
February1st to 15thDay
2313122246%68%
2121
16th to endDay
2412323337%67%
1980
March1st to 15thDay
2313424347%60%
2404
16th to endDay
221331335%7%66%
2703
April1st to 15thDay
2212213346%66%
2690
16th to endDay
221212235%74%
2666
May1st to 15thDay
2112424446%66%
2691
16th to endDay
112212447%70%
3070
June1st to 15thDay
123235%5%8%66%
2970
16th to endDay
321222345%8%63%
2940
July1st to 15thDay
6%3246%35%7%7%9%42%
2757
16th to endDay
33246%47%7%9%11%37%
2883
August1st to 15thDay
43246%46%7%8%11%40%
2514
16th to endDay
4225%6%36%6%7%10%44%
2676
September1st to 15thDay
6%5%25%4345%6%7%47%
2520
16th to endDay
5%213323345%65%
2374
October1st to 15thDay
432322224467%
2100
16th to endDay
21221222475%
2240
November1st to 15thDay
122212236%73%
2131
16th to endDay
3313213235%69%
2025
December1st to 15thDay
3412222346%66%
1913
16th to endDay
45%13323436%61%
1958
January1st to 15thNight
3322213346%66%
2912
16th to endNight
4212113346%68%
3120
February1st to 15thNight
2412212347%67%
2720
16th to endNight
2213213346%66%
2374
March1st to 15thNight
221232335%7%64%
2543
16th to endNight
2212213346%69%
2576
April1st to 15thNight
3212223348%65%
2248
16th to endNight
222212346%70%
2229
May1st to 15thNight
2213324347%63%
2249
16th to endNight
2112213347%69%
2091
June1st to 15thNight
12242446%9%61%
1699
16th to endNight
213325%6%7%8%57%
1680
July1st to 15thNight
43235%26%7%7%11%44%
1858
16th to endNight
2214436%6%7%14%44%
1989
August1st to 15thNight
3213435%8%10%12%42%
2027
16th to endNight
2222445%6%9%12%46%
2230
September1st to 15thNight
5%324435%6%6%9%47%
2100
16th to endNight
321332335%6%66%
2240
October1st to 15thNight
3312323346%66%
2520
16th to endNight
31221223375%
2688
November1st to 15thNight
111112247%73%
2701
16th to endNight
331222322470%
2925
December1st to 15thNight
432212347%65%
3033
16th to endNight
45%12213347%61%
3332

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 15thDay
18%48%18%36%12%
2017
16th to endDay
18%36%20%35%14%
2160
February1st to 15thDay
17%37%20%30%20%
2122
16th to endDay
17%25%16%38%19%
1980
March1st to 15thDay
21%37%19%30%17%
2404
16th to endDay
18%26%18%34%20%
2703
April1st to 15thDay
17%36%16%33%22%
2690
16th to endDay
13%35%15%36%26%
2666
May1st to 15thDay
18%48%14%30%23%
2691
16th to endDay
14%46%17%26%31%
3073
June1st to 15thDay
14%49%17%23%30%
2970
16th to endDay
17%5%10%15%23%27%
2940
July1st to 15thDay
33%10%14%16%12%12%
2618
16th to endDay
31%13%20%21%11%1
2728
August1st to 15thDay
32%11%18%22%11%3
2499
16th to endDay
31%10%15%20%15%6%
2676
September1st to 15thDay
32%7%13%19%19%8%
2520
16th to endDay
21%5%8%19%27%18%
2374
October1st to 15thDay
21%37%15%30%21%
2100
16th to endDay
15%25%19%33%23%
2240
November1st to 15thDay
12%27%23%35%17%
2131
16th to endDay
19%25%19%34%18%
2025
December1st to 15thDay
19%48%29%29%10%
1913
16th to endDay
23%411%23%28%8%
1958
January1st to 15thNight
19%49%17%35%13%
2912
16th to endNight
17%46%18%40%12%
3120
February1st to 15thNight
18%27%22%29%19%
2730
16th to endNight
17%35%17%35%19%
2374
March1st to 15thNight
18%37%19%31%18%
2543
16th to endNight
16%36%18%35%19%
2576
April1st to 15thNight
17%36%17%32%22%
2248
16th to endNight
14%36%16%34%25%
2229
May1st to 15thNight
19%39%13%29%23%
2250
16th to endNight
14%5%7%17%24%30%
2093
June1st to 15thNight
18%5%9%17%17%32%
1699
16th to endNight
20%7%11%14%15%30%
1680
July1st to 15thNight
28%8%14%22%14%11%
1768
16th to endNight
25%11%23%25%11%1
1881
August1st to 15thNight
27%12%22%22%12%3
2018
16th to endNight
23%11%16%27%15%6%
2230
September1st to 15thNight
30%8%16%19%15%9%
2100
16th to endNight
19%5%8%19%28%19%
2240
October1st to 15thNight
19%5%8%15%28%22%
2520
16th to endNight
13%35%16%33%27%
2688
November1st to 15thNight
11%27%22%35%20%
2701
16th to endNight
18%25%17%35%20%
2925
December1st to 15thNight
19%38%26%29%12%
3033
16th to endNight
23%39%24%28%9%
3332

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 15thDay
11%12%34%29%9%1
225
16th to endDay
5%17%33%28%13%1
240
February1st to 15thDay
6%18%33%27%13%
225
16th to endDay
7%27%35%22%5%
201
March1st to 15thDay
9%18%37%25%8%1
379
16th to endDay
7%24%37%21%7%2
480
April1st to 15thDay
9%24%35%22%7%1
449
16th to endDay
7%21%40%21%5%2
438
May1st to 15thDay
317%37%28%10%2
468
16th to endDay
311%37%30%15%
642
June1st to 15thDay
2322%38%28%4
656
16th to endDay
3214%35%37%7%
645
July1st to 15thDay
6%7%36%37%11%
452
16th to endDay
5%423%38%27%
455
August1st to 15thDay
5%7%33%34%18%
419
16th to endDay
5%8%36%34%14%
460
September1st to 15thDay
8%211%34%29%12%
435
16th to endDay
6%420%37%26%3
303
October1st to 15thDay
11%8%26%37%14%2
225
16th to endDay
6%12%23%30%17%9%
240
November1st to 15thDay
5%12%36%25%14%5%
225
16th to endDay
9%19%30%23%16%1
225
December1st to 15thDay
5%15%32%36%9%1
225
16th to endDay
10%16%34%32%5%
240
January1st to 15thNight
46%35%37%13%3
900
16th to endNight
5%9%37%32%14%1
960
February1st to 15thNight
5%8%36%37%10%1
884
16th to endNight
312%46%32%4
792
March1st to 15thNight
412%38%33%11%
900
16th to endNight
212%38%35%11%
896
April1st to 15thNight
413%43%31%7%
674
16th to endNight
411%42%34%6%
669
May1st to 15thNight
35%39%39%11%
675
16th to endNight
2432%44%14%
707
June1st to 15thNight
2226%46%20%
637
16th to endNight
2117%46%29%1
630
July1st to 15thNight
47%37%45%4
600
16th to endNight
35%22%59%8%
660
August1st to 15thNight
4425%55%9%
620
16th to endNight
25%30%54%6%
669
September1st to 15thNight
6%11%36%41%2
630
16th to endNight
4215%46%27%3
637
October1st to 15thNight
5%424%43%19%2
840
16th to endNight
45%25%37%23%4
896
November1st to 15thNight
2431%39%19%2
941
16th to endNight
6%9%26%34%20%3
1125
December1st to 15thNight
6%7%33%37%13%
1125
16th to endNight
9%9%36%35%8%
1172
Page generated at 2020-06-04 01:18:53. Version ac04

Copyright 2020 A. Danko


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