Brooksville
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Brooksville clear sky chart from 2005-11-05 to 2017-09-18.

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%
15861
21%
46958
15%
15820
60%
15820
30%
28845

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
40%
718
21%
2327
14%
716
50%
716
25%
1438
January16th to endNight
37%
768
23%
2412
16%
768
47%
768
25%
1492
February1st to 15thNight
39%
701
25%
2103
16%
698
51%
698
32%
1244
February16th to endNight
34%
631
24%
1863
11%
631
47%
631
29%
1140
March1st to 15thNight
40%
720
30%
1980
14%
720
53%
720
39%
1121
March16th to endNight
43%
768
27%
2112
17%
768
52%
768
39%
1209
April1st to 15thNight
44%
718
24%
1976
14%
718
53%
718
43%
1100
April16th to endNight
50%
696
27%
1848
16%
696
58%
696
43%
1054
May1st to 15thNight
65%
539
26%
1619
18%
539
71%
539
44%
861
May16th to endNight
70%
561
24%
1682
18%
561
74%
561
39%
946
June1st to 15thNight
67%
540
13%
1620
11%
540
68%
540
27%
1064
June16th to endNight
70%
540
9%
1620
8%
540
71%
540
25%
1113
July1st to 15thNight
75%
510
6%
1530
6%
510
75%
510
21%
1103
July16th to endNight
76%
564
6%
1595
6%
531
77%
531
22%
1138
August1st to 15thNight
76%
539
6%
1651
6%
536
77%
536
25%
1128
August16th to endNight
67%
687
10%
2024
10%
687
67%
687
22%
1405
September1st to 15thNight
63%
720
8%
1980
8%
720
64%
720
20%
1425
September16th to endNight
58%
669
15%
1848
13%
669
60%
669
22%
1308
October1st to 15thNight
62%
660
27%
1851
24%
660
67%
660
35%
1123
October16th to endNight
54%
704
29%
2112
25%
704
63%
704
35%
1206
November1st to 15thNight
49%
700
31%
2101
22%
700
61%
700
39%
1144
November16th to endNight
44%
720
29%
2268
20%
720
58%
720
34%
1281
December1st to 15thNight
44%
720
28%
2340
21%
720
55%
720
31%
1361
December16th to endNight
47%
768
24%
2496
21%
768
55%
768
29%
1441

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
8%5%26%6%46%6%6%8%37%
47813
Night
7%425%5%35%5%6%9%44%
47167
TransparencyDay
42%6%13%17%13%6%
47514
Night
34%6%16%20%15%6%
46970
SeeingDay
9%5%15%23%23%21%
5722
Night
9%5%21%30%23%7%
15869

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
11%5%25%5%345%5%10%39%
1611
16th to endDay
10%6%25%4335%47%46%
1809
February1st to 15thDay
13%5%35%423446%45%
1750
16th to endDay
9%425%5%3445%7%48%
1608
March1st to 15thDay
7%415%4345%5%8%51%
1980
16th to endDay
8%4245%35%447%48%
2111
April1st to 15thDay
7%325%6%35%5%5%8%47%
1972
16th to endDay
7%3245%35%5%5%9%49%
2118
May1st to 15thDay
6%413435%5%6%8%50%
2331
16th to endDay
7%325%6%46%6%7%9%40%
2431
June1st to 15thDay
11%5%37%6%5%7%7%7%9%26%
2340
16th to endDay
8%5%47%8%6%9%7%8%9%24%
2340
July1st to 15thDay
10%6%37%11%5%9%9%7%10%20%
2340
16th to endDay
7%6%39%9%5%9%9%9%8%19%
2465
August1st to 15thDay
8%5%27%9%6%9%8%9%10%19%
2295
16th to endDay
10%6%38%8%5%8%7%8%9%23%
2163
September1st to 15thDay
9%6%39%10%5%9%7%7%8%23%
1980
16th to endDay
10%8%36%9%5%8%8%7%7%24%
1837
October1st to 15thDay
9%5%37%6%45%6%6%6%39%
1778
16th to endDay
9%425%5%25%447%48%
1760
November1st to 15thDay
6%415%434447%53%
1757
16th to endDay
8%5%25%5%3445%8%46%
1689
December1st to 15thDay
10%6%35%5%245%6%6%43%
1620
16th to endDay
7%425%5%35%5%5%8%44%
1728
January1st to 15thNight
12%6%245%3445%9%39%
2327
16th to endNight
13%5%25%4245%5%7%43%
2412
February1st to 15thNight
11%6%2332435%5%50%
2103
16th to endNight
7%6%36%5%23448%46%
1863
March1st to 15thNight
6%42432336%7%55%
1980
16th to endNight
7%41432346%6%55%
2112
April1st to 15thNight
5%31332345%10%54%
1976
16th to endNight
6%314334448%55%
1848
May1st to 15thNight
431342445%10%55%
1619
16th to endNight
4214435%46%9%51%
1682
June1st to 15thNight
9%5%35%446%6%7%10%36%
1620
16th to endNight
7%426%6%47%8%8%11%33%
1620
July1st to 15thNight
45%36%6%37%8%9%13%31%
1620
16th to endNight
4425%7%5%9%8%9%12%29%
1703
August1st to 15thNight
4426%7%46%7%10%13%32%
1662
16th to endNight
8%5%26%5%36%7%8%12%32%
2024
September1st to 15thNight
8%5%26%7%47%7%8%11%29%
1980
16th to endNight
9%6%27%7%46%7%8%10%30%
1848
October1st to 15thNight
6%5%245%335%6%7%49%
1851
16th to endNight
9%5%14323347%52%
2112
November1st to 15thNight
6%42342335%7%54%
2101
16th to endNight
7%425%5%3445%7%50%
2268
December1st to 15thNight
10%5%25%42445%8%46%
2340
16th to endNight
8%434425%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%37%21%18%7%
1612
16th to endDay
37%37%17%23%10%
1809
February1st to 15thDay
39%46%14%18%16%
1752
16th to endDay
35%49%16%22%11%
1608
March1st to 15thDay
30%49%24%22%9%
1980
16th to endDay
35%49%20%19%10%
2112
April1st to 15thDay
34%410%18%23%8%
1972
16th to endDay
31%49%22%22%8%
2118
May1st to 15thDay
31%412%23%19%8%
2331
16th to endDay
38%6%14%20%17%3
2435
June1st to 15thDay
50%8%16%19%5%
2340
16th to endDay
50%9%22%13%3
2340
July1st to 15thDay
55%11%21%9%1
2201
16th to endDay
53%12%22%10%1
2310
August1st to 15thDay
52%12%26%8%
2282
16th to endDay
53%12%20%13%1
2163
September1st to 15thDay
55%10%18%11%3
1980
16th to endDay
53%9%13%14%6%2
1837
October1st to 15thDay
42%6%7%17%16%10%
1778
16th to endDay
35%47%17%22%13%
1760
November1st to 15thDay
31%37%23%22%11%
1757
16th to endDay
35%48%19%19%13%
1689
December1st to 15thDay
40%212%21%17%6%
1620
16th to endDay
35%5%11%21%16%8%
1728
January1st to 15thNight
39%410%21%16%6%
2327
16th to endNight
39%49%16%21%9%
2412
February1st to 15thNight
34%38%17%21%14%
2112
16th to endNight
36%5%11%16%22%7%
1863
March1st to 15thNight
28%311%26%21%7%
1980
16th to endNight
28%5%10%26%20%9%
2112
April1st to 15thNight
24%6%15%24%22%6%
1976
16th to endNight
27%314%24%22%6%
1848
May1st to 15thNight
24%5%17%27%17%8%
1620
16th to endNight
27%6%19%25%19%2
1684
June1st to 15thNight
39%7%25%21%6%
1620
16th to endNight
39%11%25%19%3
1620
July1st to 15thNight
39%17%31%10%1
1530
16th to endNight
39%15%31%11%1
1595
August1st to 15thNight
36%14%36%10%
1651
16th to endNight
40%13%26%17%1
2024
September1st to 15thNight
44%12%24%13%4
1980
16th to endNight
45%9%18%17%6%2
1848
October1st to 15thNight
32%6%10%22%19%8%
1851
16th to endNight
32%39%17%26%10%
2112
November1st to 15thNight
29%39%25%23%9%
2101
16th to endNight
33%29%22%17%13%
2268
December1st to 15thNight
35%410%26%16%6%
2340
16th to endNight
34%413%22%15%8%
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
14%14%41%14%13%2
90
16th to endDay
12%23%34%20%7%1
96
February1st to 15thDay
10%24%30%23%10%2
90
16th to endDay
12%15%32%32%7%
109
March1st to 15thDay
6%14%33%29%14%1
270
16th to endDay
11%9%26%27%20%4
288
April1st to 15thDay
8%11%25%28%20%5%
270
16th to endDay
5%5%20%31%26%9%
270
May1st to 15thDay
5%5%19%31%19%18%
288
16th to endDay
6%39%26%30%23%
331
June1st to 15thDay
16%16%18%28%28%
315
16th to endDay
7%15%13%28%43%
315
July1st to 15thDay
5%139%25%54%
305
16th to endDay
9%2414%26%42%
326
August1st to 15thDay
11%311%26%46%
313
16th to endDay
10%5%17%26%39%
332
September1st to 15thDay
13%2418%29%32%
315
16th to endDay
13%2419%35%25%
262
October1st to 15thDay
11%212%32%29%10%
255
16th to endDay
9%5%26%26%23%8%
272
November1st to 15thDay
7%322%34%25%6%
265
16th to endDay
8%5%35%32%14%4
159
December1st to 15thDay
8%12%45%27%5%
90
16th to endDay
5%5%30%43%14%1
96
January1st to 15thNight
14%12%25%34%11%
720
16th to endNight
16%13%28%32%9%
768
February1st to 15thNight
12%11%31%30%12%
704
16th to endNight
11%11%34%34%7%
631
March1st to 15thNight
8%10%36%32%11%
720
16th to endNight
8%9%34%34%13%
768
April1st to 15thNight
6%7%35%36%12%1
718
16th to endNight
8%5%29%37%16%
696
May1st to 15thNight
6%122%40%25%3
540
16th to endNight
5%114%39%31%6%
563
June1st to 15thNight
12%17%28%38%12%
540
16th to endNight
8%15%18%40%26%
540
July1st to 15thNight
7%115%42%32%
510
16th to endNight
41313%50%27%
564
August1st to 15thNight
5%1110%49%30%
539
16th to endNight
11%16%18%37%25%
687
September1st to 15thNight
10%18%25%35%17%
720
16th to endNight
11%112%28%36%8%
669
October1st to 15thNight
8%214%42%28%3
660
16th to endNight
12%5%21%33%24%2
704
November1st to 15thNight
8%5%29%35%18%3
700
16th to endNight
8%6%35%34%14%
720
December1st to 15thNight
11%8%30%33%15%
720
16th to endNight
9%9%27%34%17%1
768
Page generated at 2017-09-19 07:32:26. Version ac04

Copyright 2017 A. Danko


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