Cohen Recreational Complex
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cohen Recreational Complex clear sky chart from 2005-11-05 to 2017-09-14.

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
45%
15782
22%
46843
15%
15736
52%
15736
29%
28950

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
26%
899
21%
2494
8%
895
37%
895
24%
1636
January16th to endNight
25%
960
21%
2496
7%
960
33%
960
26%
1685
February1st to 15thNight
25%
797
17%
2205
6%
794
33%
794
21%
1540
February16th to endNight
26%
631
21%
1893
8%
631
38%
631
23%
1218
March1st to 15thNight
25%
678
18%
2118
10%
678
33%
678
20%
1429
March16th to endNight
34%
576
16%
2019
12%
576
41%
576
21%
1300
April1st to 15thNight
37%
539
23%
1797
14%
539
50%
539
28%
1031
April16th to endNight
42%
540
22%
1800
18%
540
52%
540
27%
1104
May1st to 15thNight
48%
540
18%
1694
14%
539
54%
539
26%
1086
May16th to endNight
55%
563
20%
1508
14%
561
59%
561
30%
1006
June1st to 15thNight
67%
540
22%
1440
17%
540
70%
540
43%
832
June16th to endNight
69%
540
25%
1440
17%
540
73%
540
45%
818
July1st to 15thNight
73%
510
19%
1360
16%
510
75%
510
40%
814
July16th to endNight
76%
564
22%
1487
21%
531
78%
531
41%
853
August1st to 15thNight
78%
539
23%
1715
27%
536
78%
536
40%
900
August16th to endNight
74%
573
25%
1910
30%
573
76%
573
37%
1022
September1st to 15thNight
66%
537
27%
1790
29%
537
69%
537
32%
1032
September16th to endNight
63%
622
31%
1780
23%
622
68%
622
38%
1039
October1st to 15thNight
55%
660
31%
1949
23%
660
62%
660
39%
1089
October16th to endNight
40%
704
27%
2134
18%
704
49%
704
31%
1254
November1st to 15thNight
44%
700
30%
2276
21%
700
56%
700
35%
1231
November16th to endNight
33%
720
24%
2340
17%
720
42%
720
25%
1416
December1st to 15thNight
30%
890
17%
2510
9%
890
38%
890
23%
1734
December16th to endNight
25%
960
19%
2688
7%
960
36%
960
22%
1881

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
12%5%25%5%3445%7%42%
47885
Night
12%5%24424446%46%
47025
TransparencyDay
38%5%12%24%15%2
47570
Night
37%411%24%17%3
46845
SeeingDay
13%5%19%26%23%10%
5815
Night
15%7%26%31%17%2
15783

By Month

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
16%7%36%6%24445%38%
1443
16th to endDay
12%8%36%6%34336%41%
1728
February1st to 15thDay
15%9%37%433346%38%
1657
16th to endDay
12%10%35%5%35%45%6%38%
1580
March1st to 15thDay
17%7%25%5%2435%5%38%
1851
16th to endDay
16%8%37%6%36%45%6%32%
2203
April1st to 15thDay
13%5%3432435%7%45%
2151
16th to endDay
18%5%35%5%35%446%37%
2160
May1st to 15thDay
15%425%5%3446%8%38%
2256
16th to endDay
10%5%25%6%35%46%8%39%
2605
June1st to 15thDay
6%425%5%35%46%8%46%
2520
16th to endDay
5%315%425%6%6%10%47%
2520
July1st to 15thDay
9%3145%35%5%7%10%41%
2520
16th to endDay
43145%36%7%9%11%43%
2577
August1st to 15thDay
7%4145%25%6%6%12%42%
2235
16th to endDay
7%425%5%35%5%6%10%42%
2292
September1st to 15thDay
11%5%25%42445%7%45%
2145
16th to endDay
11%5%1333345%8%48%
1837
October1st to 15thDay
12%424324346%51%
1680
16th to endDay
12%42342335%5%54%
1738
November1st to 15thDay
11%6%14413435%52%
1582
16th to endDay
18%7%235%23345%43%
1620
December1st to 15thDay
17%8%26%335%445%37%
1449
16th to endDay
18%10%344245%46%36%
1536
January1st to 15thNight
15%7%35%5%33345%42%
2494
16th to endNight
13%9%46%424446%41%
2496
February1st to 15thNight
16%8%47%5%2334438%
2196
16th to endNight
12%8%36%5%24345%42%
1893
March1st to 15thNight
18%7%35%434335%39%
2118
16th to endNight
17%6%35%5%23346%39%
2019
April1st to 15thNight
11%5%25%5%23346%48%
1797
16th to endNight
18%42342435%7%43%
1800
May1st to 15thNight
15%434435%447%43%
1694
16th to endNight
8%425%7%45%5%6%7%43%
1507
June1st to 15thNight
7%31332445%10%51%
1440
16th to endNight
43133237%6%11%52%
1440
July1st to 15thNight
7%22443446%8%51%
1440
16th to endNight
43143345%9%10%48%
1589
August1st to 15thNight
5%21343447%9%54%
1725
16th to endNight
5%4145%2345%8%53%
1910
September1st to 15thNight
10%414325%436%51%
1790
16th to endNight
9%424414346%53%
1780
October1st to 15thNight
10%314323337%55%
1949
16th to endNight
16%5%24323235%51%
2134
November1st to 15thNight
10%424423336%56%
2276
16th to endNight
17%7%3431334447%
2340
December1st to 15thNight
19%8%25%335%346%36%
2510
16th to endNight
17%9%36%42335%6%36%
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
46%311%23%13%1
1444
16th to endDay
43%313%27%10%1
1728
February1st to 15thDay
47%311%23%11%1
1659
16th to endDay
45%5%12%22%11%2
1580
March1st to 15thDay
46%49%23%13%2
1851
16th to endDay
50%6%15%17%8%
2205
April1st to 15thDay
37%411%26%17%1
2151
16th to endDay
45%5%10%25%11%1
2160
May1st to 15thDay
43%6%12%25%11%
2256
16th to endDay
40%8%13%20%14%2
2609
June1st to 15thDay
33%7%13%25%18%1
2520
16th to endDay
29%6%16%24%19%3
2520
July1st to 15thDay
34%7%13%24%14%4
2371
16th to endDay
28%8%16%29%15%1
2416
August1st to 15thDay
32%8%13%28%16%1
2221
16th to endDay
35%6%13%23%16%5%
2292
September1st to 15thDay
36%5%10%24%19%3
2145
16th to endDay
34%5%8%26%21%3
1837
October1st to 15thDay
33%48%26%21%5%
1680
16th to endDay
31%38%33%19%4
1738
November1st to 15thDay
34%39%23%20%7%
1582
16th to endDay
43%29%26%15%2
1620
December1st to 15thDay
47%5%11%22%12%
1449
16th to endDay
48%412%22%10%1
1536
January1st to 15thNight
42%310%25%16%1
2494
16th to endNight
43%312%24%13%1
2496
February1st to 15thNight
49%38%23%13%1
2205
16th to endNight
43%313%23%13%1
1893
March1st to 15thNight
46%49%20%14%3
2118
16th to endNight
45%415%23%10%
2019
April1st to 15thNight
35%311%27%19%2
1797
16th to endNight
39%49%27%16%3
1800
May1st to 15thNight
40%6%12%22%15%1
1695
16th to endNight
38%8%12%20%16%3
1509
June1st to 15thNight
27%5%14%29%20%2
1440
16th to endNight
24%6%16%24%21%6%
1440
July1st to 15thNight
30%5%13%28%14%7%
1360
16th to endNight
26%6%17%29%19%1
1487
August1st to 15thNight
24%6%14%27%23%2
1715
16th to endNight
28%412%24%23%5%
1910
September1st to 15thNight
33%5%6%28%18%7%
1790
16th to endNight
31%37%24%26%6%
1780
October1st to 15thNight
29%310%24%25%6%
1949
16th to endNight
36%27%26%21%5%
2134
November1st to 15thNight
30%310%23%24%7%
2276
16th to endNight
40%38%25%20%2
2340
December1st to 15thNight
47%412%21%12%1
2510
16th to endNight
47%411%21%12%2
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
35%7%35%16%31
90
16th to endDay
16%14%52%14%2
96
February1st to 15thDay
20%16%40%21%2
90
16th to endDay
20%14%35%20%7%
81
March1st to 15thDay
27%14%33%17%5%1
90
16th to endDay
20%11%29%29%8%
189
April1st to 15thDay
13%14%31%23%16%
270
16th to endDay
21%8%28%23%16%2
270
May1st to 15thDay
15%9%26%29%14%5%
288
16th to endDay
12%5%25%31%18%7%
505
June1st to 15thDay
8%217%29%28%14%
495
16th to endDay
6%320%35%25%8%
495
July1st to 15thDay
13%29%32%28%13%
475
16th to endDay
417%26%37%22%
515
August1st to 15thDay
12%6%21%34%24%
388
16th to endDay
12%16%23%39%16%
332
September1st to 15thDay
11%310%20%34%19%
310
16th to endDay
12%412%23%28%17%
254
October1st to 15thDay
9%219%41%21%5%
120
16th to endDay
12%332%30%20%1
96
November1st to 15thDay
5%6%23%28%21%14%
90
16th to endDay
34%10%31%15%7%1
90
December1st to 15thDay
15%8%37%24%6%6%
90
16th to endDay
30%12%40%14%2
96
January1st to 15thNight
18%16%33%25%5%
900
16th to endNight
17%13%38%26%3
960
February1st to 15thNight
19%13%34%28%2
797
16th to endNight
18%11%38%28%2
631
March1st to 15thNight
20%12%36%26%3
678
16th to endNight
19%8%29%32%9%
576
April1st to 15thNight
13%10%35%32%8%
539
16th to endNight
21%427%32%13%
540
May1st to 15thNight
15%424%40%13%2
540
16th to endNight
10%222%37%23%3
563
June1st to 15thNight
10%15%41%31%1
540
16th to endNight
6%114%43%32%1
540
July1st to 15thNight
8%16%43%35%4
510
16th to endNight
5%16%33%43%9%
564
August1st to 15thNight
6%6%32%45%7%
539
16th to endNight
6%26%34%43%7%
573
September1st to 15thNight
12%210%31%37%5%
537
16th to endNight
12%214%31%30%8%
622
October1st to 15thNight
12%323%27%27%5%
660
16th to endNight
18%6%29%31%12%
704
November1st to 15thNight
11%7%31%35%13%1
700
16th to endNight
21%9%32%26%9%
720
December1st to 15thNight
24%9%31%26%6%
890
16th to endNight
21%8%37%28%2
960
Page generated at 2017-09-15 09:29:58. Version ac04

Copyright 2017 A. Danko


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