The D'Auria's Ocala Star Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the The D'Auria's Ocala Star Observatory clear sky chart from 2005-11-05 to 2017-09-24.

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
60%
15895
21%
47017
17%
15854
65%
15854
31%
28808

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
45%
718
22%
2327
17%
716
54%
716
27%
1417
January16th to endNight
43%
768
24%
2436
18%
768
52%
768
28%
1461
February1st to 15thNight
45%
701
26%
2104
18%
698
55%
698
34%
1237
February16th to endNight
45%
631
24%
1857
14%
631
54%
631
31%
1129
March1st to 15thNight
51%
720
30%
1980
18%
720
60%
720
42%
1106
March16th to endNight
55%
768
27%
2112
20%
768
60%
768
41%
1199
April1st to 15thNight
56%
718
26%
1976
18%
718
62%
718
42%
1120
April16th to endNight
62%
701
28%
1837
19%
701
67%
701
45%
1049
May1st to 15thNight
72%
539
26%
1619
21%
539
76%
539
44%
863
May16th to endNight
77%
561
25%
1682
20%
561
78%
561
39%
968
June1st to 15thNight
69%
540
14%
1620
12%
540
70%
540
26%
1081
June16th to endNight
74%
540
9%
1620
8%
540
74%
540
25%
1114
July1st to 15thNight
75%
510
8%
1530
8%
510
75%
510
22%
1072
July16th to endNight
77%
564
6%
1595
6%
531
78%
531
23%
1105
August1st to 15thNight
75%
539
6%
1617
6%
536
75%
536
25%
1100
August16th to endNight
68%
692
11%
2029
11%
692
68%
692
22%
1418
September1st to 15thNight
66%
720
9%
1980
8%
720
66%
720
21%
1397
September16th to endNight
61%
693
15%
1914
15%
693
62%
693
22%
1357
October1st to 15thNight
69%
660
26%
1863
26%
660
71%
660
35%
1112
October16th to endNight
62%
704
29%
2112
28%
704
66%
704
35%
1221
November1st to 15thNight
61%
700
30%
2101
27%
700
68%
700
41%
1143
November16th to endNight
52%
720
28%
2270
21%
720
62%
720
33%
1298
December1st to 15thNight
53%
720
29%
2340
26%
720
59%
720
31%
1369
December16th to endNight
55%
768
24%
2496
22%
768
61%
768
30%
1472

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
9%5%26%6%46%6%6%8%38%
47893
Night
8%425%435%5%6%9%45%
47225
TransparencyDay
41%6%13%17%13%6%
47594
Night
34%6%15%20%15%6%
47028
SeeingDay
9%211%20%26%28%
5752
Night
10%316%33%28%8%
15903

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
12%6%345%3445%7%42%
1611
16th to endDay
10%5%25%4245%5%7%46%
1785
February1st to 15thDay
13%434434445%46%
1750
16th to endDay
10%6%24425%347%48%
1613
March1st to 15thDay
8%3136%2445%7%50%
1980
16th to endDay
8%5%235%346%5%7%49%
2111
April1st to 15thDay
7%414435%46%9%49%
1972
16th to endDay
7%3134345%6%8%50%
2131
May1st to 15thDay
6%3145%345%6%9%50%
2331
16th to endDay
6%325%6%5%6%6%8%8%39%
2431
June1st to 15thDay
10%5%36%8%48%7%7%8%27%
2340
16th to endDay
8%5%37%8%5%8%8%8%10%25%
2340
July1st to 15thDay
9%6%37%8%5%10%7%7%10%23%
2340
16th to endDay
7%7%49%8%6%10%7%7%10%20%
2465
August1st to 15thDay
9%5%38%7%6%10%8%10%11%18%
2328
16th to endDay
10%6%38%7%47%8%8%10%22%
2160
September1st to 15thDay
9%5%48%8%5%7%7%8%10%25%
1980
16th to endDay
11%7%47%7%7%6%6%6%7%26%
1905
October1st to 15thDay
10%5%36%6%35%5%5%7%40%
1766
16th to endDay
9%5%15%6%33346%49%
1760
November1st to 15thDay
7%5%2442435%7%53%
1757
16th to endDay
8%5%25%434446%50%
1689
December1st to 15thDay
11%6%25%43445%8%42%
1620
16th to endDay
8%425%425%5%6%9%44%
1728
January1st to 15thNight
12%5%35%4245%5%9%41%
2327
16th to endNight
14%42432445%7%44%
2436
February1st to 15thNight
11%5%25%323345%51%
2103
16th to endNight
9%5%25%5%235%5%7%45%
1857
March1st to 15thNight
6%41342335%7%55%
1980
16th to endNight
7%42432325%7%55%
2112
April1st to 15thNight
7%32232445%9%55%
1976
16th to endNight
6%31342335%7%57%
1837
May1st to 15thNight
5%31331445%9%56%
1619
16th to endNight
5%314335%6%6%9%52%
1682
June1st to 15thNight
9%435%5%46%6%6%11%36%
1620
16th to endNight
6%436%5%46%7%7%13%33%
1620
July1st to 15thNight
5%425%6%47%7%9%12%33%
1620
16th to endNight
3326%7%48%8%9%13%31%
1703
August1st to 15thNight
5%317%7%5%6%8%8%12%31%
1628
16th to endNight
9%425%6%36%5%7%12%33%
2029
September1st to 15thNight
7%6%26%6%46%6%7%12%33%
1980
16th to endNight
9%6%37%6%46%6%7%10%30%
1914
October1st to 15thNight
7%5%2442445%7%49%
1863
16th to endNight
8%425%424347%51%
2112
November1st to 15thNight
6%324424447%54%
2101
16th to endNight
8%5%24435%45%7%49%
2270
December1st to 15thNight
11%435%32435%8%46%
2340
16th to endNight
8%5%245%35%5%6%9%44%
2496

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
40%38%20%18%8%
1612
16th to endDay
37%47%18%22%10%
1785
February1st to 15thDay
39%37%13%20%15%
1752
16th to endDay
36%39%16%22%12%
1613
March1st to 15thDay
31%39%23%21%9%
1980
16th to endDay
34%311%21%18%9%
2112
April1st to 15thDay
31%410%20%23%9%
1972
16th to endDay
29%411%22%22%9%
2131
May1st to 15thDay
30%413%22%19%9%
2331
16th to endDay
38%5%15%21%15%4
2435
June1st to 15thDay
50%8%16%19%5%
2340
16th to endDay
49%9%20%16%3
2340
July1st to 15thDay
53%10%23%11%1
2201
16th to endDay
54%10%21%11%1
2310
August1st to 15thDay
52%10%24%10%1
2315
16th to endDay
53%10%18%15%1
2160
September1st to 15thDay
50%12%19%11%6%
1980
16th to endDay
54%6%13%15%7%3
1905
October1st to 15thDay
43%5%7%16%15%12%
1766
16th to endDay
35%47%14%24%13%
1760
November1st to 15thDay
30%310%22%20%12%
1757
16th to endDay
36%38%17%21%12%
1689
December1st to 15thDay
38%411%21%18%6%
1620
16th to endDay
35%5%13%21%15%9%
1728
January1st to 15thNight
39%39%21%16%8%
2327
16th to endNight
38%38%16%22%9%
2436
February1st to 15thNight
35%28%17%20%16%
2112
16th to endNight
35%5%10%16%22%9%
1857
March1st to 15thNight
27%312%26%21%9%
1980
16th to endNight
28%411%25%20%10%
2112
April1st to 15thNight
26%5%12%25%22%7%
1976
16th to endNight
26%312%27%21%7%
1837
May1st to 15thNight
24%417%27%19%7%
1620
16th to endNight
28%5%16%25%20%2
1684
June1st to 15thNight
39%9%22%23%5%
1620
16th to endNight
39%11%25%19%3
1620
July1st to 15thNight
40%13%29%13%2
1530
16th to endNight
38%14%32%11%2
1595
August1st to 15thNight
38%12%36%11%
1617
16th to endNight
41%12%25%17%2
2029
September1st to 15thNight
42%12%24%14%5%
1980
16th to endNight
46%8%17%17%7%1
1914
October1st to 15thNight
32%6%13%19%19%9%
1863
16th to endNight
33%38%15%27%11%
2112
November1st to 15thNight
28%39%25%22%9%
2101
16th to endNight
33%38%20%18%14%
2270
December1st to 15thNight
35%39%28%15%7%
2340
16th to endNight
36%412%22%14%9%
2496

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
16%5%27%31%11%7%
90
16th to endDay
11%17%35%19%13%2
96
February1st to 15thDay
10%15%27%21%21%4
90
16th to endDay
11%7%32%28%17%1
114
March1st to 15thDay
7%6%28%33%21%2
270
16th to endDay
11%321%30%27%5%
288
April1st to 15thDay
8%418%32%28%7%
270
16th to endDay
4116%24%33%18%
270
May1st to 15thDay
5%312%26%27%25%
288
16th to endDay
6%15%19%31%35%
331
June1st to 15thDay
13%2215%25%40%
315
16th to endDay
6%147%20%59%
315
July1st to 15thDay
5%16%19%66%
305
16th to endDay
10%137%23%52%
326
August1st to 15thDay
8%1410%19%54%
313
16th to endDay
11%139%21%52%
332
September1st to 15thDay
12%15%12%29%38%
315
16th to endDay
14%1113%36%33%
287
October1st to 15thDay
12%8%28%35%14%
255
16th to endDay
9%119%25%33%11%
272
November1st to 15thDay
7%213%34%32%9%
265
16th to endDay
6%323%34%27%5%
159
December1st to 15thDay
7%6%38%31%15%
90
16th to endDay
8%216%42%25%5%
96
January1st to 15thNight
15%5%27%32%17%1
720
16th to endNight
17%6%27%37%10%
768
February1st to 15thNight
14%5%28%38%11%1
704
16th to endNight
12%5%30%42%8%
631
March1st to 15thNight
7%6%30%41%13%
720
16th to endNight
9%425%42%18%1
768
April1st to 15thNight
8%325%43%18%
718
16th to endNight
6%221%45%22%
701
May1st to 15thNight
6%111%50%26%3
540
16th to endNight
6%7%34%42%7%
563
June1st to 15thNight
11%5%27%41%13%
540
16th to endNight
8%1215%44%28%
540
July1st to 15thNight
6%110%46%33%
510
16th to endNight
5%111%54%26%
564
August1st to 15thNight
5%210%50%29%
539
16th to endNight
11%314%43%25%
692
September1st to 15thNight
11%1422%41%18%
720
16th to endNight
12%26%27%42%8%
693
October1st to 15thNight
8%18%39%36%4
660
16th to endNight
10%116%36%32%2
704
November1st to 15thNight
7%319%40%26%3
700
16th to endNight
9%325%40%19%1
720
December1st to 15thNight
12%322%39%21%
720
16th to endNight
10%5%21%39%22%1
768
Page generated at 2017-09-25 09:02:23. Version ac04

Copyright 2017 A. Danko


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