Seclusion Ranch
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Seclusion Ranch clear sky chart from 2005-11-05 to 2017-12-02.

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
54%
16160
30%
47786
19%
16118
64%
16118
44%
25103

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
55%
900
31%
2506
20%
895
65%
895
50%
1299
January16th to endNight
51%
789
36%
2517
24%
789
65%
789
46%
1224
February1st to 15thNight
48%
700
28%
2163
19%
700
58%
700
38%
1190
February16th to endNight
44%
632
38%
1894
18%
632
62%
632
45%
955
March1st to 15thNight
45%
720
31%
2154
16%
720
57%
720
45%
1117
March16th to endNight
44%
651
33%
1995
16%
651
61%
651
46%
989
April1st to 15thNight
32%
539
30%
1798
15%
539
53%
539
39%
888
April16th to endNight
38%
540
24%
1800
13%
540
56%
540
35%
958
May1st to 15thNight
43%
540
25%
1668
15%
540
58%
540
34%
956
May16th to endNight
47%
562
23%
1556
12%
561
58%
561
39%
898
June1st to 15thNight
47%
540
24%
1440
12%
540
57%
540
47%
795
June16th to endNight
60%
540
24%
1440
15%
540
67%
540
46%
800
July1st to 15thNight
63%
510
21%
1360
15%
510
67%
510
35%
851
July16th to endNight
73%
564
22%
1458
21%
531
73%
531
37%
882
August1st to 15thNight
67%
539
14%
1755
15%
536
69%
536
29%
1050
August16th to endNight
73%
573
26%
1910
29%
573
75%
573
37%
1013
September1st to 15thNight
62%
540
28%
1800
24%
540
72%
540
38%
937
September16th to endNight
62%
537
38%
1965
33%
537
74%
537
50%
836
October1st to 15thNight
55%
645
34%
2085
23%
645
64%
645
49%
975
October16th to endNight
64%
804
39%
2340
23%
804
73%
804
55%
1129
November1st to 15thNight
62%
950
37%
2470
20%
950
70%
950
60%
1235
November16th to endNight
60%
975
39%
2535
23%
975
67%
975
55%
1318
December1st to 15thNight
51%
910
31%
2489
16%
910
62%
910
49%
1321
December16th to endNight
47%
960
31%
2688
16%
960
59%
960
43%
1487

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
431332445%8%58%
48672
Night
5%41332345%7%59%
47962
Cloud CoverDay
431332445%8%58%
48670
Night
441332345%7%59%
47962
TransparencyDay
23%49%24%25%13%
48351
Night
24%39%24%25%12%
47786
SeeingDay
7%6%23%30%24%8%
5996
Night
6%428%40%16%1
16165

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
3423212236%67%
1432
16th to endDay
2423313335%66%
1716
February1st to 15thDay
35%34423346%57%
1699
16th to endDay
25%2333345%5%61%
1580
March1st to 15thDay
2413324347%61%
1805
16th to endDay
5%42332345%8%56%
2228
April1st to 15thDay
5%41232445%6%58%
2150
16th to endDay
8%6%13324347%52%
2160
May1st to 15thDay
8%41332445%7%52%
2280
16th to endDay
5%21232446%9%57%
2555
June1st to 15thDay
5%2132245%6%10%54%
2520
16th to endDay
2122235%7%10%61%
2520
July1st to 15thDay
3212325%7%8%12%49%
2520
16th to endDay
3213335%6%9%11%49%
2608
August1st to 15thDay
42135%36%5%8%11%46%
2193
16th to endDay
4312425%46%10%55%
2292
September1st to 15thDay
6%3133235%6%8%55%
2160
16th to endDay
422223246%67%
1995
October1st to 15thDay
5%211213345%66%
1872
16th to endDay
421221224471%
1870
November1st to 15thDay
2312122347%68%
1718
16th to endDay
331322345%69%
1755
December1st to 15thDay
25%24213347%61%
1508
16th to endDay
47%24313346%57%
1536
January1st to 15thNight
3324323335%64%
2506
16th to endNight
3413313345%64%
2517
February1st to 15thNight
46%35%423335%56%
2153
16th to endNight
35%2322235%5%62%
1894
March1st to 15thNight
6%5%12323346%59%
2154
16th to endNight
4312214447%62%
1995
April1st to 15thNight
5%42332335%6%58%
1798
16th to endNight
8%414424445%55%
1800
May1st to 15thNight
10%414424447%51%
1667
16th to endNight
8%314325%45%6%53%
1555
June1st to 15thNight
431332445%8%58%
1440
16th to endNight
3214325%6%6%10%53%
1440
July1st to 15thNight
7%215%5%26%6%9%9%42%
1440
16th to endNight
5%214425%6%8%10%46%
1557
August1st to 15thNight
5%3245%36%7%7%10%42%
1764
16th to endNight
5%213425%6%8%9%50%
1910
September1st to 15thNight
6%21343446%9%52%
1800
16th to endNight
4211213446%67%
1965
October1st to 15thNight
5%312212336%67%
2085
16th to endNight
4312212235%69%
2340
November1st to 15thNight
2212113347%69%
2470
16th to endNight
45%12212236%66%
2535
December1st to 15thNight
2425%31235%6%61%
2489
16th to endNight
45%24324335%58%
2688

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 15thDay
2423212237%67%
1432
16th to endDay
2422314336%66%
1716
February1st to 15thDay
35%3342335%6%57%
1699
16th to endDay
242332445%6%60%
1580
March1st to 15thDay
2413324348%60%
1805
16th to endDay
5%42332345%8%56%
2226
April1st to 15thDay
5%41232445%6%58%
2150
16th to endDay
8%5%1333335%7%52%
2160
May1st to 15thDay
7%5%13325%45%7%52%
2280
16th to endDay
43122145%6%9%56%
2555
June1st to 15thDay
5%2132245%7%10%54%
2520
16th to endDay
21112235%7%10%60%
2520
July1st to 15thDay
3213325%7%8%11%49%
2520
16th to endDay
3213335%6%8%12%49%
2608
August1st to 15thDay
4214436%6%8%12%46%
2193
16th to endDay
421332447%9%55%
2292
September1st to 15thDay
6%3133235%6%8%55%
2160
16th to endDay
422213335%68%
1995
October1st to 15thDay
5%211213345%66%
1872
16th to endDay
421221234470%
1870
November1st to 15thDay
221221335%7%67%
1718
16th to endDay
331322345%69%
1755
December1st to 15thDay
25%23213347%61%
1508
16th to endDay
36%24314346%57%
1536
January1st to 15thNight
3324323335%64%
2506
16th to endNight
3413313245%64%
2517
February1st to 15thNight
47%35%323336%56%
2153
16th to endNight
26%23223445%62%
1894
March1st to 15thNight
6%5%22313346%60%
2154
16th to endNight
4312214447%62%
1995
April1st to 15thNight
5%5%1332245%7%58%
1798
16th to endNight
8%4135%24445%55%
1800
May1st to 15thNight
9%414424448%50%
1667
16th to endNight
7%413335%46%6%53%
1555
June1st to 15thNight
421332445%7%58%
1440
16th to endNight
3213425%5%7%10%53%
1440
July1st to 15thNight
6%3145%36%6%8%9%42%
1440
16th to endNight
5%214426%6%8%10%46%
1557
August1st to 15thNight
43246%36%7%8%10%42%
1764
16th to endNight
5%213425%6%8%9%49%
1910
September1st to 15thNight
5%3134345%6%9%52%
1800
16th to endNight
421223446%67%
1965
October1st to 15thNight
5%312212335%67%
2085
16th to endNight
4312212235%69%
2340
November1st to 15thNight
2212212347%68%
2470
16th to endNight
4412212236%66%
2535
December1st to 15thNight
242432235%6%61%
2489
16th to endNight
45%24324345%59%
2688

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
19%18%30%31%9%
1433
16th to endDay
21%15%29%31%10%
1716
February1st to 15thDay
28%27%28%23%9%
1700
16th to endDay
23%25%24%29%13%
1580
March1st to 15thDay
22%27%23%27%16%
1805
16th to endDay
24%37%25%27%11%
2228
April1st to 15thDay
25%36%25%24%14%
2150
16th to endDay
30%37%24%24%9%
2160
May1st to 15thDay
29%5%12%20%23%8%
2280
16th to endDay
23%5%12%22%21%14%
2559
June1st to 15thDay
23%411%22%22%16%
2520
16th to endDay
17%48%23%27%19%
2520
July1st to 15thDay
25%7%12%21%21%12%
2371
16th to endDay
24%8%15%26%20%5%
2445
August1st to 15thDay
28%7%16%22%14%9%
2178
16th to endDay
23%5%10%25%23%10%
2292
September1st to 15thDay
25%5%10%24%23%11%
2160
16th to endDay
18%27%23%29%18%
1995
October1st to 15thDay
18%38%18%31%19%
1872
16th to endDay
16%2323%33%19%
1870
November1st to 15thDay
15%26%25%29%20%
1718
16th to endDay
18%1320%34%20%
1755
December1st to 15thDay
23%29%28%26%8%
1508
16th to endDay
27%39%28%22%7%
1536
January1st to 15thNight
22%17%30%27%10%
2506
16th to endNight
22%26%26%31%10%
2517
February1st to 15thNight
30%28%27%23%6%
2163
16th to endNight
23%15%26%30%12%
1894
March1st to 15thNight
25%25%24%32%9%
2154
16th to endNight
21%39%23%28%12%
1995
April1st to 15thNight
25%27%27%22%14%
1798
16th to endNight
29%312%22%20%10%
1800
May1st to 15thNight
31%411%20%20%10%
1668
16th to endNight
28%5%14%18%17%14%
1556
June1st to 15thNight
23%414%21%17%18%
1440
16th to endNight
24%411%19%20%18%
1440
July1st to 15thNight
33%7%11%21%16%10%
1360
16th to endNight
29%8%17%23%17%4
1458
August1st to 15thNight
33%8%20%19%10%7%
1755
16th to endNight
25%7%12%27%19%7%
1910
September1st to 15thNight
27%415%25%18%9%
1800
16th to endNight
17%38%23%30%16%
1965
October1st to 15thNight
19%210%17%31%18%
2085
16th to endNight
18%25%20%32%20%
2340
November1st to 15thNight
16%25%24%30%20%
2470
16th to endNight
20%15%21%32%19%
2535
December1st to 15thNight
23%29%30%26%7%
2489
16th to endNight
27%29%25%26%8%
2688

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
10%322%36%23%4
90
16th to endDay
6%5%27%31%17%12%
96
February1st to 15thDay
7%5%34%34%16%1
90
16th to endDay
36%37%33%18%1
81
March1st to 15thDay
210%30%37%15%3
95
16th to endDay
13%20%32%22%7%3
288
April1st to 15thDay
13%17%36%22%5%4
269
16th to endDay
17%19%31%22%8%
270
May1st to 15thDay
11%11%29%32%14%1
417
16th to endDay
9%7%27%31%19%4
517
June1st to 15thDay
7%6%24%27%25%9%
495
16th to endDay
5%122%29%31%9%
495
July1st to 15thDay
5%113%31%37%11%
475
16th to endDay
417%28%41%17%
467
August1st to 15thDay
7%215%34%27%13%
315
16th to endDay
6%111%40%29%10%
332
September1st to 15thDay
5%422%31%24%10%
315
16th to endDay
12%222%24%26%12%
150
October1st to 15thDay
5%326%25%29%8%
135
16th to endDay
6%222%23%29%15%
144
November1st to 15thDay
3317%34%32%7%
135
16th to endDay
14%10%27%23%21%2
135
December1st to 15thDay
3442%40%7%2
94
16th to endDay
7%10%32%37%12%
96
January1st to 15thNight
4429%41%17%3
900
16th to endNight
7%332%42%12%1
789
February1st to 15thNight
9%331%45%9%
704
16th to endNight
6%9%35%40%7%
632
March1st to 15thNight
8%5%36%38%9%
720
16th to endNight
5%8%38%38%8%
651
April1st to 15thNight
7%10%45%30%5%
539
16th to endNight
12%8%37%33%8%
540
May1st to 15thNight
12%7%33%35%11%
540
16th to endNight
9%432%36%14%1
563
June1st to 15thNight
5%338%37%13%1
540
16th to endNight
5%226%46%20%
540
July1st to 15thNight
8%215%43%28%2
510
16th to endNight
6%19%41%38%3
564
August1st to 15thNight
6%212%39%35%3
539
16th to endNight
6%112%45%30%3
573
September1st to 15thNight
8%221%39%26%2
540
16th to endNight
5%425%39%23%2
537
October1st to 15thNight
7%328%41%15%2
645
16th to endNight
5%223%41%22%3
804
November1st to 15thNight
35%25%46%19%1
950
16th to endNight
7%5%23%44%17%1
975
December1st to 15thNight
4333%45%11%1
910
16th to endNight
6%5%33%40%12%1
960
Page generated at 2017-12-03 09:16:41. Version ac04

Copyright 2017 A. Danko


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