Fort Myers Beach
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Fort Myers Beach clear sky chart from 2005-11-05 to 2017-09-21.

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
65%
16025
19%
47027
17%
15988
69%
15988
30%
29670

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
57%
716
19%
2327
18%
716
61%
716
28%
1403
January16th to endNight
57%
768
26%
2382
23%
768
63%
768
32%
1412
February1st to 15thNight
53%
699
24%
2107
20%
698
59%
698
34%
1261
February16th to endNight
61%
631
29%
1819
22%
631
69%
631
42%
999
March1st to 15thNight
62%
720
30%
1980
21%
720
69%
720
47%
1077
March16th to endNight
66%
768
29%
2112
23%
768
70%
768
44%
1184
April1st to 15thNight
71%
718
23%
1976
19%
718
74%
718
47%
1066
April16th to endNight
64%
720
26%
1881
20%
720
68%
720
41%
1119
May1st to 15thNight
80%
617
26%
1697
21%
617
82%
617
48%
925
May16th to endNight
76%
561
19%
1683
17%
561
77%
561
32%
1038
June1st to 15thNight
66%
540
8%
1620
6%
540
67%
540
19%
1188
June16th to endNight
75%
540
6%
1620
5%
540
75%
540
21%
1201
July1st to 15thNight
73%
510
5%
1530
5%
510
73%
510
18%
1166
July16th to endNight
78%
564
7%
1595
7%
531
79%
531
25%
1115
August1st to 15thNight
74%
539
6%
1678
6%
536
74%
536
20%
1208
August16th to endNight
66%
741
5%
2078
5%
741
66%
741
17%
1570
September1st to 15thNight
66%
720
5%
1980
6%
720
66%
720
18%
1493
September16th to endNight
59%
681
6%
1881
6%
681
60%
681
15%
1480
October1st to 15thNight
70%
660
22%
1854
22%
660
71%
660
33%
1170
October16th to endNight
59%
704
23%
2112
22%
704
63%
704
28%
1337
November1st to 15thNight
65%
700
29%
2101
27%
700
70%
700
38%
1187
November16th to endNight
62%
720
29%
2178
26%
720
68%
720
34%
1283
December1st to 15thNight
60%
720
24%
2340
24%
720
65%
720
30%
1390
December16th to endNight
65%
768
24%
2496
25%
768
68%
768
35%
1398

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
6%425%5%36%6%7%10%41%
47821
Night
7%425%5%35%5%6%9%43%
47231
TransparencyDay
37%11%16%18%12%4
47522
Night
34%9%17%20%14%4
47034
SeeingDay
8%110%22%27%28%
5869
Night
8%113%32%31%12%
16037

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
8%425%426%45%9%44%
1611
16th to endDay
9%5%144245%5%9%47%
1839
February1st to 15thDay
9%425%32335%8%51%
1750
16th to endDay
5%31343335%9%55%
1652
March1st to 15thDay
311333446%9%58%
1980
16th to endDay
44235%3445%7%54%
2111
April1st to 15thDay
4234145%6%10%56%
1972
16th to endDay
4313335%35%10%53%
2079
May1st to 15thDay
32221447%9%60%
2262
16th to endDay
7%325%446%6%7%11%42%
2431
June1st to 15thDay
12%6%25%6%46%7%8%11%27%
2340
16th to endDay
7%425%7%5%8%8%10%12%27%
2340
July1st to 15thDay
6%5%37%8%5%9%9%10%11%21%
2340
16th to endDay
6%416%8%5%9%11%10%12%22%
2465
August1st to 15thDay
5%427%8%5%8%8%9%12%26%
2267
16th to endDay
8%5%26%9%6%7%8%8%11%25%
2112
September1st to 15thDay
6%427%9%5%8%8%9%11%26%
1980
16th to endDay
9%7%37%7%5%8%6%8%10%23%
1872
October1st to 15thDay
6%5%25%6%45%6%7%9%40%
1774
16th to endDay
10%5%14435%6%7%7%45%
1760
November1st to 15thDay
5%4234245%6%8%52%
1757
16th to endDay
6%3235%3445%9%52%
1779
December1st to 15thDay
7%4245%3445%9%45%
1620
16th to endDay
5%325%4346%5%9%49%
1728
January1st to 15thNight
8%5%25%425%6%7%10%42%
2327
16th to endNight
9%414435%5%6%9%45%
2382
February1st to 15thNight
9%6%24323446%50%
2103
16th to endNight
5%21343446%9%54%
1819
March1st to 15thNight
42133245%49%57%
1980
16th to endNight
322433446%10%54%
2112
April1st to 15thNight
5%21332346%10%56%
1976
16th to endNight
5%41442446%7%52%
1881
May1st to 15thNight
2212325%5%5%9%58%
1697
16th to endNight
6%4135%26%5%7%9%45%
1682
June1st to 15thNight
11%5%346%47%7%9%10%28%
1620
16th to endNight
6%425%7%5%8%7%9%13%29%
1620
July1st to 15thNight
6%426%7%37%7%9%12%29%
1620
16th to endNight
4325%6%47%8%10%12%32%
1703
August1st to 15thNight
6%5%26%6%46%6%8%12%32%
1689
16th to endNight
9%5%36%7%36%6%8%12%29%
2078
September1st to 15thNight
6%5%28%8%47%8%9%11%26%
1980
16th to endNight
10%6%38%7%6%7%7%7%12%23%
1881
October1st to 15thNight
5%5%25%6%25%5%7%10%44%
1854
16th to endNight
11%5%25%5%35%45%7%44%
2112
November1st to 15thNight
6%324424447%54%
2101
16th to endNight
7%4244245%5%8%50%
2178
December1st to 15thNight
7%5%25%435%5%48%47%
2340
16th to endNight
5%43432446%9%50%
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
34%9%10%24%15%4
1612
16th to endDay
32%7%10%24%19%5%
1839
February1st to 15thDay
31%6%10%20%20%11%
1752
16th to endDay
27%5%13%22%21%8%
1652
March1st to 15thDay
23%5%14%28%22%6%
1980
16th to endDay
28%6%11%23%20%8%
2112
April1st to 15thDay
23%8%19%25%18%5%
1972
16th to endDay
26%8%13%22%24%3
2079
May1st to 15thDay
21%7%17%28%19%6%
2262
16th to endDay
34%11%17%22%12%
2435
June1st to 15thDay
49%12%20%14%2
2340
16th to endDay
46%16%22%11%2
2340
July1st to 15thDay
52%19%20%7%
2201
16th to endDay
48%20%22%9%
2310
August1st to 15thDay
45%19%26%7%
2254
16th to endDay
51%16%23%7%
2112
September1st to 15thDay
49%17%21%9%1
1980
16th to endDay
53%14%16%10%3
1872
October1st to 15thDay
37%12%14%15%16%4
1774
16th to endDay
35%7%11%17%18%8%
1760
November1st to 15thDay
29%5%11%22%21%9%
1757
16th to endDay
30%7%10%19%20%12%
1779
December1st to 15thDay
37%8%12%20%14%5%
1620
16th to endDay
31%7%14%22%18%5%
1728
January1st to 15thNight
35%7%14%25%13%3
2327
16th to endNight
33%5%11%23%19%6%
2382
February1st to 15thNight
34%48%20%20%11%
2112
16th to endNight
25%5%14%24%22%7%
1819
March1st to 15thNight
24%413%30%22%5%
1980
16th to endNight
23%6%13%27%20%6%
2112
April1st to 15thNight
21%6%18%31%17%4
1976
16th to endNight
27%7%12%23%24%4
1881
May1st to 15thNight
21%6%18%27%19%5%
1698
16th to endNight
33%8%17%25%15%
1684
June1st to 15thNight
46%12%22%14%3
1620
16th to endNight
42%16%26%12%3
1620
July1st to 15thNight
43%19%28%8%1
1530
16th to endNight
36%15%33%13%
1595
August1st to 15thNight
40%16%30%11%
1678
16th to endNight
45%16%28%8%
2078
September1st to 15thNight
45%16%27%9%1
1980
16th to endNight
50%16%19%10%3
1881
October1st to 15thNight
32%9%18%18%17%3
1854
16th to endNight
38%6%10%17%20%6%
2112
November1st to 15thNight
29%5%10%21%23%8%
2101
16th to endNight
31%6%9%20%20%10%
2178
December1st to 15thNight
34%6%13%22%17%4
2340
16th to endNight
28%7%14%22%21%5%
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%425%34%15%3
90
16th to endDay
16%13%26%27%14%2
96
February1st to 15thDay
25%27%31%24%8%
90
16th to endDay
6%228%43%17%
153
March1st to 15thDay
4123%41%24%4
270
16th to endDay
7%317%38%29%3
288
April1st to 15thDay
4118%35%32%6%
270
16th to endDay
6%112%36%34%8%
270
May1st to 15thDay
5%9%28%35%21%
288
16th to endDay
5%5%19%35%33%
331
June1st to 15thDay
16%17%11%27%34%
315
16th to endDay
4210%21%61%
315
July1st to 15thDay
416%22%64%
305
16th to endDay
9%17%25%55%
326
August1st to 15thDay
7%17%23%60%
313
16th to endDay
15%210%25%46%
332
September1st to 15thDay
7%139%26%51%
315
16th to endDay
10%210%32%43%
275
October1st to 15thDay
6%17%28%36%19%
255
16th to endDay
12%120%27%23%13%
272
November1st to 15thDay
10%11%30%32%14%
265
16th to endDay
6%119%38%30%3
249
December1st to 15thDay
21%215%42%16%2
90
16th to endDay
3214%31%39%9%
96
January1st to 15thNight
11%319%38%25%1
720
16th to endNight
9%424%42%19%
768
February1st to 15thNight
10%324%42%17%
704
16th to endNight
6%223%47%20%
631
March1st to 15thNight
5%226%42%22%
720
16th to endNight
5%119%49%22%
768
April1st to 15thNight
5%116%49%25%1
718
16th to endNight
5%119%44%26%1
720
May1st to 15thNight
49%46%36%3
618
16th to endNight
7%433%46%7%
563
June1st to 15thNight
14%5%15%45%18%
540
16th to endNight
4112%42%38%
540
July1st to 15thNight
6%26%39%46%
510
16th to endNight
5%16%36%50%
564
August1st to 15thNight
7%17%41%42%
539
16th to endNight
10%411%37%34%
741
September1st to 15thNight
9%414%39%31%
720
16th to endNight
12%16%16%41%21%
681
October1st to 15thNight
8%7%35%38%9%
660
16th to endNight
13%116%33%27%7%
704
November1st to 15thNight
8%18%39%28%4
700
16th to endNight
8%316%42%26%2
720
December1st to 15thNight
9%219%40%26%1
720
16th to endNight
7%219%36%31%2
768
Page generated at 2017-09-22 07:35:31. Version ac04

Copyright 2017 A. Danko


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