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 2019-06-10.

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
66%
18376
20%
53940
18%
18339
69%
18339
31%
33703

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%
836
22%
2717
21%
836
62%
836
30%
1594
January16th to endNight
54%
896
24%
2779
21%
896
60%
896
31%
1663
February1st to 15thNight
56%
819
24%
2467
20%
818
61%
818
34%
1474
February16th to endNight
65%
735
29%
2119
23%
735
71%
735
45%
1133
March1st to 15thNight
62%
840
31%
2310
21%
840
70%
840
47%
1252
March16th to endNight
65%
896
29%
2464
23%
896
70%
896
45%
1372
April1st to 15thNight
71%
838
24%
2306
20%
838
74%
838
46%
1263
April16th to endNight
65%
831
26%
2170
20%
831
68%
831
44%
1257
May1st to 15thNight
78%
721
24%
1981
19%
721
80%
721
45%
1113
May16th to endNight
75%
657
19%
1971
17%
657
75%
657
31%
1234
June1st to 15thNight
68%
612
9%
1836
8%
612
69%
612
21%
1314
June16th to endNight
75%
585
6%
1755
5%
585
75%
585
20%
1314
July1st to 15thNight
74%
555
5%
1665
5%
555
74%
555
18%
1266
July16th to endNight
78%
612
6%
1739
7%
579
79%
579
25%
1208
August1st to 15thNight
74%
575
6%
1787
6%
572
75%
572
20%
1288
August16th to endNight
67%
803
5%
2252
5%
803
67%
803
17%
1705
September1st to 15thNight
67%
780
5%
2145
6%
780
67%
780
17%
1625
September16th to endNight
61%
777
6%
2145
6%
777
61%
777
16%
1644
October1st to 15thNight
70%
780
22%
2192
22%
780
71%
780
32%
1385
October16th to endNight
60%
832
23%
2496
23%
832
64%
832
29%
1562
November1st to 15thNight
67%
820
28%
2461
27%
820
71%
820
38%
1389
November16th to endNight
62%
840
28%
2541
26%
840
68%
840
34%
1489
December1st to 15thNight
61%
840
26%
2730
25%
840
67%
840
32%
1579
December16th to endNight
67%
896
25%
2912
27%
896
70%
896
37%
1580

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%42%
54556
Night
6%425%5%35%5%6%10%44%
54144
TransparencyDay
36%11%16%18%12%4
54257
Night
33%9%17%20%14%4
53947
SeeingDay
7%111%25%28%25%
8178
Night
8%113%32%31%12%
18388

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
7%424426%45%9%47%
1881
16th to endDay
8%5%144245%5%9%46%
2145
February1st to 15thDay
8%32432345%8%52%
2050
16th to endDay
5%31342335%9%57%
1924
March1st to 15thDay
321233435%8%60%
2310
16th to endDay
5%3145%3345%7%55%
2463
April1st to 15thDay
3234245%5%10%56%
2302
16th to endDay
4313425%35%10%55%
2395
May1st to 15thDay
421331447%9%56%
2640
16th to endDay
8%325%436%5%7%10%42%
2847
June1st to 15thDay
10%5%25%6%36%7%9%11%30%
2652
16th to endDay
7%425%7%5%8%9%10%12%26%
2535
July1st to 15thDay
6%437%8%5%10%9%11%11%21%
2535
16th to endDay
6%316%8%6%9%10%10%12%23%
2673
August1st to 15thDay
5%427%8%5%8%8%9%12%27%
2411
16th to endDay
8%5%26%8%6%7%8%8%11%26%
2289
September1st to 15thDay
6%326%9%5%8%8%9%11%26%
2145
16th to endDay
8%6%27%7%5%8%7%8%10%25%
2145
October1st to 15thDay
5%5%25%6%46%6%8%9%38%
2096
16th to endDay
9%414435%6%7%7%46%
2080
November1st to 15thDay
5%3244245%6%9%52%
2057
16th to endDay
5%3245%345%5%9%50%
2075
December1st to 15thDay
7%4245%3445%8%48%
1890
16th to endDay
5%2244245%6%10%50%
2016
January1st to 15thNight
8%5%25%4245%6%10%44%
2717
16th to endNight
9%4145%35%5%6%9%44%
2779
February1st to 15thNight
8%6%24324446%50%
2463
16th to endNight
5%21332446%8%57%
2119
March1st to 15thNight
4213324449%57%
2310
16th to endNight
421333446%9%56%
2464
April1st to 15thNight
421332346%10%55%
2306
16th to endNight
431342446%8%54%
2170
May1st to 15thNight
3213325%5%5%9%56%
1981
16th to endNight
7%4245%26%5%6%8%45%
1970
June1st to 15thNight
10%5%346%37%7%9%11%31%
1836
16th to endNight
5%435%7%5%8%7%9%13%28%
1755
July1st to 15thNight
6%426%8%37%7%9%12%30%
1755
16th to endNight
4325%6%47%8%10%12%33%
1847
August1st to 15thNight
6%5%26%6%46%7%9%12%31%
1798
16th to endNight
8%5%36%7%46%6%8%12%29%
2252
September1st to 15thNight
6%5%27%8%47%8%9%12%26%
2145
16th to endNight
9%6%38%7%5%6%6%7%12%26%
2145
October1st to 15thNight
5%5%25%6%25%5%6%10%45%
2192
16th to endNight
9%5%25%5%3445%7%45%
2496
November1st to 15thNight
6%32442445%7%54%
2461
16th to endNight
7%4244345%5%8%48%
2541
December1st to 15thNight
6%425%4345%48%49%
2730
16th to endNight
5%42432446%11%50%
2912

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
31%9%10%24%18%4
1882
16th to endDay
32%6%10%24%18%5%
2145
February1st to 15thDay
30%6%12%22%18%9%
2052
16th to endDay
25%5%15%22%23%8%
1924
March1st to 15thDay
22%5%15%27%21%7%
2310
16th to endDay
28%6%11%23%22%8%
2464
April1st to 15thDay
22%8%19%25%18%5%
2302
16th to endDay
25%8%13%23%25%4
2395
May1st to 15thDay
24%7%18%25%18%5%
2640
16th to endDay
35%11%15%20%15%1
2851
June1st to 15thDay
46%14%22%14%2
2652
16th to endDay
46%17%22%11%1
2535
July1st to 15thDay
52%19%20%7%
2396
16th to endDay
46%19%23%10%
2518
August1st to 15thDay
44%18%27%8%
2398
16th to endDay
51%15%24%7%
2289
September1st to 15thDay
48%18%22%9%1
2145
16th to endDay
52%14%18%11%3
2145
October1st to 15thDay
38%12%14%16%14%3
2096
16th to endDay
35%7%11%16%18%9%
2080
November1st to 15thDay
29%6%12%22%20%8%
2057
16th to endDay
30%8%10%19%20%10%
2075
December1st to 15thDay
34%8%12%23%14%6%
1890
16th to endDay
28%7%14%26%17%4
2016
January1st to 15thNight
33%7%14%24%16%4
2717
16th to endNight
33%6%11%23%18%5%
2779
February1st to 15thNight
33%5%10%21%18%9%
2472
16th to endNight
23%5%14%23%25%7%
2119
March1st to 15thNight
23%414%29%21%6%
2310
16th to endNight
23%6%13%27%22%6%
2464
April1st to 15thNight
22%6%18%31%16%4
2306
16th to endNight
25%6%12%25%23%5%
2170
May1st to 15thNight
23%6%19%25%19%5%
1982
16th to endNight
34%8%16%23%17%
1972
June1st to 15thNight
43%12%23%16%3
1836
16th to endNight
42%17%25%11%2
1755
July1st to 15thNight
42%19%29%7%1
1665
16th to endNight
36%15%33%14%
1739
August1st to 15thNight
40%17%30%11%
1787
16th to endNight
45%17%28%8%
2252
September1st to 15thNight
44%17%26%9%1
2145
16th to endNight
48%15%21%11%3
2145
October1st to 15thNight
33%9%18%19%15%3
2192
16th to endNight
36%7%10%16%21%7%
2496
November1st to 15thNight
28%6%11%24%22%7%
2461
16th to endNight
30%7%11%20%20%9%
2541
December1st to 15thNight
32%6%13%24%18%5%
2730
16th to endNight
26%6%15%26%19%4
2912

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
10%5%28%33%19%3
180
16th to endDay
13%9%31%32%11%1
192
February1st to 15thDay
3317%40%28%6%
180
16th to endDay
4220%42%26%3
243
March1st to 15thDay
5%223%40%24%2
390
16th to endDay
6%319%40%27%2
416
April1st to 15thDay
3121%35%30%7%
390
16th to endDay
5%212%37%34%7%
379
May1st to 15thDay
7%10%32%32%16%
408
16th to endDay
9%6%19%34%29%
459
June1st to 15thDay
12%16%12%31%35%
411
16th to endDay
429%22%60%
375
July1st to 15thDay
316%23%64%
365
16th to endDay
9%110%27%51%
390
August1st to 15thDay
6%17%25%58%
358
16th to endDay
13%29%25%48%
396
September1st to 15thDay
7%139%28%49%
375
16th to endDay
8%210%32%44%
374
October1st to 15thDay
6%19%29%34%18%
375
16th to endDay
9%219%28%25%14%
400
November1st to 15thDay
8%110%30%35%13%
385
16th to endDay
5%120%41%27%3
365
December1st to 15thDay
13%225%40%15%3
180
16th to endDay
2311%31%39%10%
192
January1st to 15thNight
10%320%38%25%1
840
16th to endNight
9%425%42%17%
896
February1st to 15thNight
9%323%42%20%
824
16th to endNight
6%120%46%23%
735
March1st to 15thNight
5%225%43%22%
840
16th to endNight
5%120%48%22%
896
April1st to 15thNight
5%116%48%26%1
838
16th to endNight
5%119%45%26%1
831
May1st to 15thNight
410%45%36%3
722
16th to endNight
8%5%33%44%7%
659
June1st to 15thNight
12%414%48%19%
612
16th to endNight
4112%40%41%
585
July1st to 15thNight
5%26%38%46%
555
16th to endNight
5%16%36%50%
612
August1st to 15thNight
7%17%41%41%
575
16th to endNight
10%410%36%36%
803
September1st to 15thNight
8%313%40%32%
780
16th to endNight
11%15%16%41%23%
777
October1st to 15thNight
8%8%34%39%8%
780
16th to endNight
11%115%34%29%7%
832
November1st to 15thNight
7%17%38%31%4
820
16th to endNight
8%217%43%25%2
840
December1st to 15thNight
8%220%41%25%1
840
16th to endNight
6%217%36%33%3
896
Page generated at 2019-06-10 19:29:45. Version ac04

Copyright 2019 A. Danko


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