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 2017-04-25.

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%
15411
30%
45582
19%
15369
64%
15369
44%
23883

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
39%
525
25%
1750
14%
525
57%
525
36%
916
May1st to 15thNight
42%
495
26%
1529
15%
495
57%
495
33%
877
May16th to endNight
48%
514
22%
1423
12%
513
59%
513
40%
808
June1st to 15thNight
46%
495
26%
1320
13%
495
56%
495
47%
733
June16th to endNight
61%
495
23%
1320
14%
495
67%
495
46%
726
July1st to 15thNight
63%
465
22%
1240
15%
465
67%
465
34%
781
July16th to endNight
74%
522
22%
1342
21%
489
74%
489
38%
804
August1st to 15thNight
68%
494
15%
1608
16%
491
70%
491
29%
953
August16th to endNight
72%
525
24%
1750
27%
525
75%
525
36%
944
September1st to 15thNight
60%
495
30%
1650
25%
495
70%
495
38%
860
September16th to endNight
65%
492
38%
1801
34%
492
76%
492
53%
737
October1st to 15thNight
54%
591
35%
1911
24%
591
64%
591
49%
896
October16th to endNight
64%
737
37%
2145
22%
737
73%
737
55%
1032
November1st to 15thNight
64%
875
38%
2275
20%
875
72%
875
61%
1127
November16th to endNight
60%
900
38%
2340
23%
900
66%
900
54%
1231
December1st to 15thNight
51%
900
31%
2463
16%
900
62%
900
48%
1309
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%
46064
Night
441332345%7%59%
45758
Cloud CoverDay
431332445%8%58%
46062
Night
441332345%7%59%
45758
TransparencyDay
23%49%24%25%13%
45743
Night
24%39%24%25%12%
45582
SeeingDay
7%7%24%30%23%7%
5117
Night
6%428%41%16%1
15416

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%13333347%53%
2098
May1st to 15thDay
7%4133245%5%7%53%
2089
16th to endDay
421232447%9%57%
2336
June1st to 15thDay
5%2133246%6%10%53%
2310
16th to endDay
2122235%7%10%61%
2310
July1st to 15thDay
3312325%7%8%12%48%
2310
16th to endDay
3213335%6%9%10%50%
2416
August1st to 15thDay
32135%36%5%7%11%46%
2010
16th to endDay
4212425%46%10%54%
2100
September1st to 15thDay
6%3133235%6%8%54%
1980
16th to endDay
312223246%70%
1829
October1st to 15thDay
421122345%6%66%
1716
16th to endDay
5%21121223471%
1714
November1st to 15thDay
1212122347%68%
1583
16th to endDay
33132224469%
1620
December1st to 15thDay
25%24313347%61%
1497
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%56%
1750
May1st to 15thNight
9%414424447%51%
1528
16th to endNight
7%214325%46%6%55%
1422
June1st to 15thNight
431332445%8%57%
1320
16th to endNight
3214325%5%6%10%53%
1320
July1st to 15thNight
6%225%5%26%7%9%9%41%
1320
16th to endNight
4214426%6%9%10%47%
1441
August1st to 15thNight
42245%36%7%7%10%43%
1617
16th to endNight
5%213425%6%8%8%50%
1750
September1st to 15thNight
6%22333446%9%52%
1650
16th to endNight
3211113446%69%
1801
October1st to 15thNight
5%312212336%66%
1911
16th to endNight
4212212335%69%
2145
November1st to 15thNight
2212113347%70%
2275
16th to endNight
45%12212235%66%
2340
December1st to 15thNight
2425%31235%6%61%
2463
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%53%
2098
May1st to 15thDay
7%5%23325%45%7%52%
2089
16th to endDay
43123145%6%9%56%
2336
June1st to 15thDay
5%3132245%7%10%53%
2310
16th to endDay
21112235%7%10%61%
2310
July1st to 15thDay
3213325%7%9%11%48%
2310
16th to endDay
3213335%6%9%11%50%
2416
August1st to 15thDay
3214436%6%8%11%46%
2010
16th to endDay
4213325%5%7%9%54%
2100
September1st to 15thDay
6%3133235%6%8%54%
1980
16th to endDay
312213345%70%
1829
October1st to 15thDay
421121445%6%66%
1716
16th to endDay
5%21221233471%
1714
November1st to 15thDay
121221335%7%67%
1583
16th to endDay
34132234469%
1620
December1st to 15thDay
25%24313347%61%
1497
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%56%
1750
May1st to 15thNight
9%414424448%50%
1528
16th to endNight
6%314335%46%6%54%
1422
June1st to 15thNight
431342446%7%58%
1320
16th to endNight
3213425%5%7%10%54%
1320
July1st to 15thNight
5%325%5%36%7%9%9%41%
1320
16th to endNight
4214426%6%8%10%47%
1441
August1st to 15thNight
33246%36%7%8%10%43%
1617
16th to endNight
5%213425%6%8%9%49%
1750
September1st to 15thNight
5%4134245%6%8%52%
1650
16th to endNight
321123446%69%
1801
October1st to 15thNight
5%312212336%66%
1911
16th to endNight
422212336%69%
2145
November1st to 15thNight
2212212347%69%
2275
16th to endNight
45%13212235%66%
2340
December1st to 15thNight
242432235%6%61%
2463
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
29%37%24%24%9%
2098
May1st to 15thDay
29%5%12%19%23%9%
2089
16th to endDay
23%5%13%22%20%15%
2340
June1st to 15thDay
24%410%22%22%14%
2310
16th to endDay
17%48%22%27%19%
2310
July1st to 15thDay
26%7%13%21%19%12%
2161
16th to endDay
24%7%14%27%21%5%
2253
August1st to 15thDay
28%7%15%22%15%10%
1995
16th to endDay
24%5%11%25%23%10%
2100
September1st to 15thDay
26%5%10%22%23%11%
1980
16th to endDay
16%26%24%30%19%
1829
October1st to 15thDay
18%39%19%32%17%
1716
16th to endDay
16%2323%33%19%
1714
November1st to 15thDay
15%26%24%28%21%
1583
16th to endDay
18%1319%35%20%
1620
December1st to 15thDay
23%29%28%26%8%
1497
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
28%313%22%20%10%
1750
May1st to 15thNight
32%412%19%20%11%
1529
16th to endNight
26%6%15%18%19%14%
1423
June1st to 15thNight
24%413%22%19%16%
1320
16th to endNight
23%5%11%20%20%19%
1320
July1st to 15thNight
33%7%11%22%14%10%
1240
16th to endNight
28%8%17%24%17%4
1342
August1st to 15thNight
32%9%19%19%11%8%
1608
16th to endNight
26%7%12%27%18%7%
1750
September1st to 15thNight
27%414%24%18%9%
1650
16th to endNight
15%28%24%31%16%
1801
October1st to 15thNight
20%210%17%32%16%
1911
16th to endNight
18%25%20%33%19%
2145
November1st to 15thNight
15%26%24%29%21%
2275
16th to endNight
21%1421%31%19%
2340
December1st to 15thNight
23%29%30%27%7%
2463
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
16%18%32%22%9%
250
May1st to 15thDay
10%12%31%30%13%1
346
16th to endDay
9%7%26%32%19%4
437
June1st to 15thDay
8%7%26%25%23%8%
420
16th to endDay
4122%30%30%11%
420
July1st to 15thDay
6%114%32%38%7%
400
16th to endDay
417%30%43%12%
401
August1st to 15thDay
5%217%34%25%14%
255
16th to endDay
6%211%43%27%8%
268
September1st to 15thDay
5%5%27%34%23%3
255
16th to endDay
2319%22%34%17%
104
October1st to 15thDay
2324%30%28%11%
90
16th to endDay
7%219%23%33%13%
96
November1st to 15thDay
2310%31%42%11%
90
16th to endDay
17%12%24%24%18%2
90
December1st to 15thDay
3441%41%7%2
90
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
10%8%38%33%8%
525
May1st to 15thNight
12%7%34%33%11%
495
16th to endNight
9%432%36%15%1
515
June1st to 15thNight
5%439%36%12%
495
16th to endNight
4126%47%20%
495
July1st to 15thNight
7%216%44%26%2
465
16th to endNight
5%19%42%37%3
522
August1st to 15thNight
5%213%39%36%3
494
16th to endNight
7%111%45%30%3
525
September1st to 15thNight
8%223%40%23%2
495
16th to endNight
4423%39%24%2
492
October1st to 15thNight
7%328%40%15%3
591
16th to endNight
5%323%42%21%3
737
November1st to 15thNight
2424%46%20%1
875
16th to endNight
7%5%23%44%17%1
900
December1st to 15thNight
4333%45%11%1
900
16th to endNight
6%5%33%40%12%1
960
Page generated at 2017-04-26 15:21:41. Version ac04

Copyright 2017 A. Danko


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