Winter Haven
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Winter Haven 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
60%
16269
21%
47842
17%
16228
65%
16228
31%
29822

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
46%
718
20%
2327
15%
716
54%
716
25%
1447
January16th to endNight
46%
768
26%
2436
19%
768
56%
768
30%
1435
February1st to 15thNight
47%
701
25%
2103
17%
698
56%
698
33%
1237
February16th to endNight
44%
631
26%
1827
14%
631
55%
631
34%
1069
March1st to 15thNight
50%
720
30%
1980
18%
720
60%
720
41%
1128
March16th to endNight
56%
768
27%
2112
20%
768
62%
768
41%
1202
April1st to 15thNight
60%
718
24%
1976
18%
718
64%
718
44%
1095
April16th to endNight
60%
720
28%
1848
17%
720
65%
720
45%
1065
May1st to 15thNight
69%
584
27%
1664
20%
584
73%
584
42%
924
May16th to endNight
75%
561
23%
1683
18%
561
77%
561
35%
1001
June1st to 15thNight
70%
540
11%
1620
9%
540
70%
540
24%
1142
June16th to endNight
70%
540
7%
1620
6%
540
70%
540
20%
1190
July1st to 15thNight
73%
510
6%
1530
5%
510
73%
510
19%
1162
July16th to endNight
74%
564
7%
1595
6%
531
75%
531
21%
1160
August1st to 15thNight
80%
539
6%
1609
6%
536
80%
536
25%
1111
August16th to endNight
65%
726
7%
2061
7%
726
65%
726
21%
1481
September1st to 15thNight
63%
720
7%
1980
7%
720
63%
720
19%
1448
September16th to endNight
59%
717
13%
1980
12%
717
60%
717
20%
1426
October1st to 15thNight
68%
720
25%
2046
25%
720
70%
720
33%
1259
October16th to endNight
58%
768
30%
2304
26%
768
65%
768
34%
1359
November1st to 15thNight
63%
760
30%
2281
26%
760
70%
760
40%
1256
November16th to endNight
53%
780
31%
2399
25%
780
63%
780
34%
1398
December1st to 15thNight
53%
728
26%
2365
23%
728
61%
728
31%
1386
December16th to endNight
56%
768
24%
2496
23%
768
61%
768
32%
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%36%7%46%6%6%8%36%
48589
Night
7%425%5%35%5%6%9%43%
48050
TransparencyDay
43%6%13%16%13%5%
48290
Night
35%7%16%20%14%5%
47853
SeeingDay
9%212%21%25%28%
6109
Night
9%317%33%28%9%
16277

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%435%5%35%5%6%9%39%
1611
16th to endDay
10%5%25%42446%7%47%
1785
February1st to 15thDay
10%5%345%15%45%8%44%
1750
16th to endDay
8%5%245%2446%6%48%
1646
March1st to 15thDay
5%3245%35%5%5%7%51%
1980
16th to endDay
8%4244345%5%5%49%
2111
April1st to 15thDay
44246%46%5%5%9%45%
1972
16th to endDay
6%4246%37%5%6%8%45%
2112
May1st to 15thDay
43145%35%6%6%8%47%
2295
16th to endDay
6%436%7%49%7%7%7%33%
2431
June1st to 15thDay
12%8%38%9%46%6%7%9%21%
2340
16th to endDay
8%7%48%9%6%8%8%7%9%22%
2340
July1st to 15thDay
9%6%49%9%5%8%8%7%8%21%
2340
16th to endDay
9%7%49%10%6%9%7%7%9%19%
2465
August1st to 15thDay
5%6%310%10%6%9%8%8%10%22%
2338
16th to endDay
11%7%47%9%6%7%6%6%10%22%
2124
September1st to 15thDay
9%6%49%9%6%7%6%7%9%22%
1980
16th to endDay
10%7%48%8%6%8%7%7%8%22%
1980
October1st to 15thDay
8%6%36%7%46%6%5%8%35%
1914
16th to endDay
8%5%246%35%5%47%45%
1920
November1st to 15thDay
5%4245%36%5%5%7%49%
1907
16th to endDay
7%5%25%6%45%45%7%44%
1888
December1st to 15thDay
9%5%36%5%345%6%8%41%
1632
16th to endDay
7%5%245%35%6%6%7%44%
1728
January1st to 15thNight
9%6%36%5%36%5%5%8%41%
2327
16th to endNight
10%5%25%425%5%6%8%44%
2436
February1st to 15thNight
11%6%24323446%50%
2103
16th to endNight
7%425%42445%7%49%
1827
March1st to 15thNight
5%2235%2445%7%54%
1980
16th to endNight
6%21442445%7%54%
2112
April1st to 15thNight
5%21442446%9%54%
1976
16th to endNight
5%41432345%8%55%
1848
May1st to 15thNight
33234245%5%8%56%
1664
16th to endNight
6%3235%35%5%7%10%47%
1682
June1st to 15thNight
8%6%36%6%46%6%7%10%32%
1620
16th to endNight
6%5%36%8%38%8%8%11%29%
1620
July1st to 15thNight
7%6%37%7%47%6%7%11%29%
1620
16th to endNight
4436%8%49%7%9%12%28%
1703
August1st to 15thNight
3426%7%5%7%7%9%11%35%
1620
16th to endNight
8%5%35%7%5%6%7%8%11%30%
2061
September1st to 15thNight
7%6%37%7%46%6%8%12%28%
1980
16th to endNight
11%7%36%7%47%6%7%10%28%
1980
October1st to 15thNight
5%426%6%345%7%9%44%
2046
16th to endNight
8%5%25%423448%48%
2304
November1st to 15thNight
6%32442435%6%56%
2281
16th to endNight
8%4245%3445%7%49%
2399
December1st to 15thNight
9%5%25%425%5%5%8%46%
2365
16th to endNight
6%5%25%5%35%46%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
39%5%7%21%19%5%
1612
16th to endDay
35%38%18%24%9%
1785
February1st to 15thDay
38%37%15%21%13%
1752
16th to endDay
34%49%17%22%10%
1646
March1st to 15thDay
30%310%25%21%8%
1980
16th to endDay
33%310%22%20%9%
2112
April1st to 15thDay
35%5%11%19%21%7%
1972
16th to endDay
35%5%10%18%22%8%
2112
May1st to 15thDay
31%5%13%21%19%8%
2295
16th to endDay
44%6%12%19%14%2
2435
June1st to 15thDay
55%7%16%17%3
2340
16th to endDay
54%9%20%12%2
2340
July1st to 15thDay
55%13%21%9%1
2201
16th to endDay
56%11%20%10%1
2310
August1st to 15thDay
51%11%27%8%
2325
16th to endDay
55%11%20%10%1
2124
September1st to 15thDay
54%11%19%11%2
1980
16th to endDay
55%8%16%12%6%1
1980
October1st to 15thDay
43%7%10%15%15%7%
1914
16th to endDay
38%5%7%14%21%12%
1920
November1st to 15thDay
31%47%24%23%8%
1907
16th to endDay
37%47%21%17%11%
1888
December1st to 15thDay
39%411%19%19%5%
1632
16th to endDay
35%5%13%19%18%7%
1728
January1st to 15thNight
40%410%21%16%6%
2327
16th to endNight
36%49%21%19%9%
2436
February1st to 15thNight
34%38%17%22%13%
2112
16th to endNight
32%5%13%18%22%7%
1827
March1st to 15thNight
27%410%28%21%7%
1980
16th to endNight
27%412%25%21%8%
2112
April1st to 15thNight
25%5%15%26%20%7%
1976
16th to endNight
26%414%25%22%7%
1848
May1st to 15thNight
25%6%14%26%19%7%
1665
16th to endNight
29%8%18%24%16%2
1684
June1st to 15thNight
44%8%22%18%4
1620
16th to endNight
44%13%21%15%3
1620
July1st to 15thNight
45%15%26%10%1
1530
16th to endNight
41%15%29%12%
1595
August1st to 15thNight
36%14%37%10%
1609
16th to endNight
44%12%29%12%1
2061
September1st to 15thNight
44%14%24%14%2
1980
16th to endNight
48%8%19%16%32
1980
October1st to 15thNight
34%6%13%21%18%6%
2046
16th to endNight
34%48%19%23%10%
2304
November1st to 15thNight
28%410%24%24%8%
2281
16th to endNight
33%38%21%20%11%
2399
December1st to 15thNight
35%412%25%15%7%
2365
16th to endNight
33%414%23%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
21%430%26%14%3
90
16th to endDay
16%13%30%19%18%1
96
February1st to 15thDay
413%30%23%20%8%
90
16th to endDay
10%5%38%29%14%
147
March1st to 15thDay
5%428%34%24%1
270
16th to endDay
9%5%22%27%28%6%
288
April1st to 15thDay
4323%31%27%9%
270
16th to endDay
8%29%29%33%15%
270
May1st to 15thDay
5%112%26%32%22%
288
16th to endDay
6%6%20%29%37%
331
June1st to 15thDay
18%16%11%20%40%
315
16th to endDay
6%136%23%58%
315
July1st to 15thDay
6%5%21%66%
305
16th to endDay
8%1311%19%56%
326
August1st to 15thDay
5%149%19%58%
313
16th to endDay
12%1310%20%52%
332
September1st to 15thDay
11%1310%30%42%
315
16th to endDay
11%313%34%36%
314
October1st to 15thDay
11%19%27%34%14%
315
16th to endDay
10%422%30%25%7%
336
November1st to 15thDay
6%115%37%28%11%
325
16th to endDay
8%219%40%25%4
268
December1st to 15thDay
11%226%39%19%1
94
16th to endDay
6%7%11%38%29%7%
96
January1st to 15thNight
11%7%25%36%17%1
720
16th to endNight
12%6%28%38%14%
768
February1st to 15thNight
13%5%27%39%12%1
704
16th to endNight
10%5%32%40%11%
631
March1st to 15thNight
6%432%41%13%
720
16th to endNight
7%426%43%17%
768
April1st to 15thNight
6%322%45%20%
718
16th to endNight
7%421%43%22%
720
May1st to 15thNight
4115%46%28%3
585
16th to endNight
6%8%36%39%7%
563
June1st to 15thNight
9%1425%44%14%
540
16th to endNight
7%1313%43%30%
540
July1st to 15thNight
9%19%43%35%
510
16th to endNight
6%17%44%38%
564
August1st to 15thNight
319%49%34%
539
16th to endNight
11%1316%39%26%
726
September1st to 15thNight
10%1422%38%22%
720
16th to endNight
14%5%23%41%12%
717
October1st to 15thNight
8%10%36%37%5%
720
16th to endNight
12%217%33%29%4
768
November1st to 15thNight
6%218%42%25%3
760
16th to endNight
8%227%41%19%1
780
December1st to 15thNight
9%423%38%22%
728
16th to endNight
7%423%41%21%2
768
Page generated at 2017-12-03 11:16:36. Version ac04

Copyright 2017 A. Danko


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