Caney Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Caney Observatory 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
42%
16069
24%
47882
15%
16022
51%
16022
30%
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
23%
900
25%
2327
8%
895
35%
895
26%
1507
January16th to endNight
23%
960
26%
2496
7%
960
35%
960
31%
1563
February1st to 15thNight
23%
880
20%
2288
5%
876
32%
876
26%
1487
February16th to endNight
20%
633
24%
1895
6%
633
35%
633
25%
1160
March1st to 15thNight
29%
540
21%
1980
11%
540
40%
540
20%
1245
March16th to endNight
30%
576
16%
2112
12%
576
38%
576
18%
1388
April1st to 15thNight
30%
539
23%
1803
11%
539
47%
539
30%
1023
April16th to endNight
32%
540
21%
1800
13%
540
46%
540
25%
1114
May1st to 15thNight
42%
540
19%
1680
15%
540
49%
540
26%
1076
May16th to endNight
49%
563
18%
1606
14%
561
55%
561
28%
1035
June1st to 15thNight
69%
540
22%
1440
17%
540
72%
540
46%
805
June16th to endNight
69%
540
25%
1440
18%
540
73%
540
45%
823
July1st to 15thNight
71%
510
17%
1504
16%
510
72%
510
34%
896
July16th to endNight
81%
564
26%
1594
27%
531
84%
531
44%
853
August1st to 15thNight
79%
539
24%
1611
28%
536
79%
536
40%
893
August16th to endNight
73%
573
24%
1910
27%
573
75%
573
35%
1047
September1st to 15thNight
67%
540
27%
1800
29%
540
71%
540
33%
1017
September16th to endNight
59%
587
30%
1982
25%
587
66%
587
33%
1083
October1st to 15thNight
50%
720
27%
2160
19%
720
56%
720
35%
1245
October16th to endNight
42%
768
32%
2304
19%
768
53%
768
36%
1283
November1st to 15thNight
40%
760
30%
2309
17%
760
52%
760
33%
1322
November16th to endNight
33%
887
26%
2642
14%
887
44%
887
27%
1613
December1st to 15thNight
29%
910
20%
2547
8%
910
38%
910
25%
1669
December16th to endNight
25%
960
22%
2652
8%
960
35%
960
23%
1803

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
13%6%25%5%2445%7%43%
48548
Night
12%5%24423446%49%
48078
TransparencyDay
39%6%12%23%15%2
48248
Night
34%5%12%24%18%3
47883
SeeingDay
14%7%23%27%20%5%
6036
Night
15%9%28%29%15%1
16069

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
15%5%2442333448%
1611
16th to endDay
13%7%25%422345%47%
1728
February1st to 15thDay
14%7%26%5%14336%42%
1575
16th to endDay
15%9%35%5%24336%40%
1586
March1st to 15thDay
16%7%245%2435%5%41%
1980
16th to endDay
19%7%26%42445%6%35%
2110
April1st to 15thDay
15%6%34423346%44%
2145
16th to endDay
20%8%36%43445%5%34%
2160
May1st to 15thDay
18%5%25%5%35%45%7%36%
2269
16th to endDay
12%6%35%6%26%46%8%37%
2505
June1st to 15thDay
8%5%246%35%5%6%8%44%
2520
16th to endDay
6%3135%36%5%7%10%45%
2520
July1st to 15thDay
10%425%5%46%6%6%9%37%
2361
16th to endDay
6%4145%36%7%7%10%42%
2466
August1st to 15thDay
9%315%5%35%6%7%10%40%
2337
16th to endDay
7%425%6%35%5%6%8%43%
2292
September1st to 15thDay
13%5%145%35%35%7%44%
2160
16th to endDay
9%6%25%42445%6%47%
1962
October1st to 15thDay
15%42443323452%
1800
16th to endDay
12%5%23323235%54%
1920
November1st to 15thDay
14%6%13213345%53%
1878
16th to endDay
19%5%2341223448%
1644
December1st to 15thDay
17%7%25%423345%43%
1450
16th to endDay
16%9%35%424346%38%
1569
January1st to 15thNight
15%6%25%5%2333448%
2327
16th to endNight
10%7%24423335%51%
2496
February1st to 15thNight
13%7%26%423346%46%
2278
16th to endNight
12%6%24424446%48%
1895
March1st to 15thNight
16%8%3442334442%
1980
16th to endNight
18%8%35%324345%38%
2112
April1st to 15thNight
12%5%13313446%52%
1803
16th to endNight
16%6%2332345%8%43%
1800
May1st to 15thNight
14%5%23424447%45%
1679
16th to endNight
11%425%5%245%6%9%43%
1605
June1st to 15thNight
6%21332245%10%56%
1440
16th to endNight
32234245%5%9%55%
1440
July1st to 15thNight
5%3145%35%6%7%9%47%
1594
16th to endNight
322343345%11%55%
1702
August1st to 15thNight
6%212425%5%6%8%52%
1621
16th to endNight
5%314335%5%5%9%51%
1910
September1st to 15thNight
9%413323448%51%
1800
16th to endNight
8%424423346%54%
1982
October1st to 15thNight
11%41342345%6%52%
2160
16th to endNight
11%41432233457%
2304
November1st to 15thNight
11%6%23313336%54%
2309
16th to endNight
16%6%23313335%49%
2642
December1st to 15thNight
19%6%24323347%42%
2547
16th to endNight
17%9%34413435%41%
2652

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
38%310%25%18%2
1612
16th to endDay
39%412%28%13%3
1728
February1st to 15thDay
42%414%24%12%2
1576
16th to endDay
45%49%24%13%3
1586
March1st to 15thDay
43%5%9%21%15%4
1980
16th to endDay
48%6%13%18%11%1
2112
April1st to 15thDay
40%5%10%23%17%1
2145
16th to endDay
50%5%10%17%12%2
2160
May1st to 15thDay
46%7%12%21%12%
2269
16th to endDay
44%9%14%20%9%1
2509
June1st to 15thDay
35%8%13%26%15%
2520
16th to endDay
31%7%16%27%13%2
2520
July1st to 15thDay
39%9%14%24%11%1
2222
16th to endDay
31%9%18%26%13%
2311
August1st to 15thDay
35%9%16%22%15%1
2323
16th to endDay
35%7%14%22%14%5%
2292
September1st to 15thDay
38%5%11%22%15%6%
2160
16th to endDay
35%5%9%27%19%2
1962
October1st to 15thDay
35%49%24%20%5%
1800
16th to endDay
32%38%28%20%6%
1920
November1st to 15thDay
33%38%27%19%7%
1878
16th to endDay
40%39%20%24%1
1644
December1st to 15thDay
43%411%23%15%1
1450
16th to endDay
46%5%10%20%14%2
1569
January1st to 15thNight
39%39%24%20%2
2327
16th to endNight
34%412%28%17%2
2496
February1st to 15thNight
38%5%11%26%15%2
2288
16th to endNight
37%313%24%17%3
1895
March1st to 15thNight
43%5%10%20%16%4
1980
16th to endNight
47%5%9%22%13%1
2112
April1st to 15thNight
32%413%24%20%4
1803
16th to endNight
38%6%10%26%15%2
1800
May1st to 15thNight
39%7%13%20%17%2
1680
16th to endNight
36%9%16%21%13%1
1607
June1st to 15thNight
22%6%17%30%21%1
1440
16th to endNight
25%6%14%29%19%4
1440
July1st to 15thNight
29%9%15%26%17%2
1504
16th to endNight
22%7%15%34%18%1
1594
August1st to 15thNight
25%7%16%30%18%1
1611
16th to endNight
26%8%16%23%18%5%
1910
September1st to 15thNight
30%6%9%28%17%7%
1800
16th to endNight
30%5%10%21%28%3
1982
October1st to 15thNight
31%412%21%23%6%
2160
16th to endNight
30%39%25%22%8%
2304
November1st to 15thNight
32%38%25%21%7%
2309
16th to endNight
37%47%23%23%3
2642
December1st to 15thNight
41%411%23%16%2
2547
16th to endNight
46%310%21%13%3
2652

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
26%31%28%12%1
90
16th to endDay
25%32%23%13%5%
96
February1st to 15thDay
22%15%50%8%21
90
16th to endDay
25%19%33%17%3
81
March1st to 15thDay
31%20%32%15%1
90
16th to endDay
18%25%42%10%3
96
April1st to 15thDay
17%16%33%21%9%
264
16th to endDay
26%12%30%20%9%1
270
May1st to 15thDay
18%12%32%22%12%1
406
16th to endDay
15%7%38%22%12%2
517
June1st to 15thDay
10%320%36%24%5%
495
16th to endDay
7%225%36%22%6%
495
July1st to 15thDay
12%216%36%25%6%
475
16th to endDay
6%7%29%35%18%
515
August1st to 15thDay
12%112%29%36%8%
490
16th to endDay
12%9%34%33%9%
332
September1st to 15thDay
11%312%27%35%10%
315
16th to endDay
9%223%34%25%4
180
October1st to 15thDay
13%11%29%31%11%1
135
16th to endDay
15%9%36%29%7%1
144
November1st to 15thDay
19%9%32%28%9%
135
16th to endDay
26%17%26%20%8%
135
December1st to 15thDay
18%22%32%15%7%3
94
16th to endDay
23%21%38%14%1
96
January1st to 15thNight
22%17%34%21%4
900
16th to endNight
15%19%40%21%3
960
February1st to 15thNight
18%17%37%24%2
880
16th to endNight
17%16%42%21%2
633
March1st to 15thNight
20%12%34%29%2
540
16th to endNight
22%11%32%26%7%
576
April1st to 15thNight
15%11%40%26%5%
539
16th to endNight
18%9%38%25%7%
540
May1st to 15thNight
15%6%32%33%12%
540
16th to endNight
12%328%35%18%1
563
June1st to 15thNight
6%217%45%26%1
540
16th to endNight
5%18%42%30%2
540
July1st to 15thNight
6%14%40%34%4
510
16th to endNight
37%33%48%7%
564
August1st to 15thNight
7%16%36%41%7%
539
16th to endNight
6%10%40%35%5%
573
September1st to 15thNight
12%112%34%34%4
540
16th to endNight
11%219%35%25%5%
587
October1st to 15thNight
12%5%27%30%20%3
720
16th to endNight
14%10%29%32%12%
768
November1st to 15thNight
16%10%31%30%12%
760
16th to endNight
20%11%31%25%10%
887
December1st to 15thNight
22%12%32%26%5%
910
16th to endNight
23%15%31%24%3
960
Page generated at 2017-12-03 10:16:40. Version ac04

Copyright 2017 A. Danko


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