Mustang Island State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mustang Island State Park clear sky chart from 2005-11-05 to 2017-09-17.

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%
15236
22%
46972
17%
15194
59%
15194
27%
28432

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
35%
898
20%
2327
9%
895
41%
895
21%
1612
January16th to endNight
43%
877
22%
2413
11%
877
49%
877
26%
1569
February1st to 15thNight
43%
703
24%
2112
13%
700
51%
700
25%
1285
February16th to endNight
44%
584
22%
1846
13%
584
49%
584
24%
1092
March1st to 15thNight
39%
540
25%
1980
18%
540
48%
540
20%
1185
March16th to endNight
51%
576
22%
2112
18%
576
58%
576
25%
1180
April1st to 15thNight
44%
539
19%
1977
15%
539
52%
539
20%
1185
April16th to endNight
42%
540
20%
1875
17%
540
50%
540
20%
1169
May1st to 15thNight
50%
539
21%
1638
17%
539
56%
539
25%
1019
May16th to endNight
59%
561
21%
1683
20%
561
63%
561
27%
996
June1st to 15thNight
70%
540
19%
1620
18%
540
74%
540
34%
875
June16th to endNight
66%
540
15%
1620
19%
540
67%
540
29%
963
July1st to 15thNight
69%
510
15%
1530
19%
510
70%
510
31%
927
July16th to endNight
73%
564
20%
1594
23%
531
79%
531
40%
882
August1st to 15thNight
83%
539
26%
1661
30%
536
84%
536
51%
790
August16th to endNight
72%
573
17%
2048
21%
573
73%
573
26%
1211
September1st to 15thNight
71%
540
16%
1980
20%
540
72%
540
24%
1208
September16th to endNight
65%
498
21%
1837
22%
498
67%
498
22%
1130
October1st to 15thNight
74%
522
30%
1842
31%
522
75%
522
36%
960
October16th to endNight
71%
704
30%
2112
23%
704
73%
704
39%
1160
November1st to 15thNight
54%
700
24%
2100
19%
700
57%
700
28%
1295
November16th to endNight
46%
789
27%
2229
12%
789
57%
789
28%
1350
December1st to 15thNight
41%
900
22%
2340
12%
900
45%
900
22%
1654
December16th to endNight
34%
960
18%
2496
7%
960
40%
960
19%
1735

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
10%42442446%9%45%
47798
Night
11%42442445%8%46%
47169
TransparencyDay
34%8%17%22%13%4
47498
Night
34%7%15%21%14%6%
46974
SeeingDay
8%8%7%22%36%16%
5184
Night
11%16%10%25%28%7%
15242

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
21%5%36%434446%34%
1611
16th to endDay
18%6%25%333445%42%
1821
February1st to 15thDay
17%5%3432345%5%44%
1750
16th to endDay
16%5%24413347%44%
1628
March1st to 15thDay
19%5%24333337%41%
1980
16th to endDay
9%5%24433447%49%
2110
April1st to 15thDay
11%5%3442446%8%44%
1971
16th to endDay
12%5%3443445%7%45%
2085
May1st to 15thDay
9%435%5%345%6%8%43%
2309
16th to endDay
5%313435%5%6%11%48%
2430
June1st to 15thDay
21123245%7%12%55%
2340
16th to endDay
43235%35%6%8%14%42%
2340
July1st to 15thDay
7%325%5%25%47%11%44%
2340
16th to endDay
5%323335%5%6%12%48%
2466
August1st to 15thDay
21123135%7%10%60%
2286
16th to endDay
8%314425%6%7%13%41%
2154
September1st to 15thDay
9%5%26%5%36%6%8%9%35%
1980
16th to endDay
10%424436%47%10%41%
1828
October1st to 15thDay
5%2235%3446%10%52%
1775
16th to endDay
8%313324347%57%
1760
November1st to 15thDay
9%6%24425%5%6%7%45%
1758
16th to endDay
13%5%145%24436%48%
1728
December1st to 15thDay
22%6%25%32445%6%36%
1620
16th to endDay
20%7%26%323447%36%
1728
January1st to 15thNight
22%5%25%423335%41%
2327
16th to endNight
18%42432335%6%44%
2413
February1st to 15thNight
15%424324446%47%
2102
16th to endNight
13%5%24423436%49%
1846
March1st to 15thNight
15%7%25%422346%44%
1980
16th to endNight
9%5%34333247%51%
2112
April1st to 15thNight
11%6%245%3436%9%42%
1977
16th to endNight
11%7%35%5%245%5%8%40%
1875
May1st to 15thNight
8%6%245%246%7%9%42%
1637
16th to endNight
5%415%436%5%8%13%41%
1683
June1st to 15thNight
32144245%8%12%50%
1620
16th to endNight
5%323435%6%8%15%40%
1620
July1st to 15thNight
5%4244246%7%12%44%
1620
16th to endNight
42113245%6%12%53%
1702
August1st to 15thNight
111222246%11%64%
1671
16th to endNight
5%3245%35%5%6%11%47%
2048
September1st to 15thNight
8%5%23435%7%6%11%42%
1980
16th to endNight
9%425%6%345%6%10%41%
1837
October1st to 15thNight
5%31332446%8%57%
1842
16th to endNight
7%413314246%58%
2112
November1st to 15thNight
10%425%423447%49%
2100
16th to endNight
12%414423345%53%
2229
December1st to 15thNight
21%6%24323446%40%
2340
16th to endNight
20%7%34323447%39%
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
51%49%14%12%7%
1612
16th to endDay
42%410%16%16%9%
1821
February1st to 15thDay
41%5%9%15%16%10%
1751
16th to endDay
39%5%10%20%16%7%
1628
March1st to 15thDay
43%412%16%15%7%
1980
16th to endDay
34%7%14%18%16%8%
2112
April1st to 15thDay
36%5%16%19%15%6%
1971
16th to endDay
37%7%13%23%12%7%
2085
May1st to 15thDay
35%7%17%20%11%6%
2309
16th to endDay
27%9%18%26%16%1
2434
June1st to 15thDay
18%9%19%32%18%
2340
16th to endDay
27%11%25%28%6%
2340
July1st to 15thDay
30%10%25%27%5%
2201
16th to endDay
26%10%33%27%2
2311
August1st to 15thDay
18%8%31%36%4
2272
16th to endDay
31%13%26%22%4
2154
September1st to 15thDay
41%13%17%19%7%1
1980
16th to endDay
36%11%12%21%14%3
1828
October1st to 15thDay
27%7%13%22%22%5%
1775
16th to endDay
26%5%10%24%23%9%
1760
November1st to 15thDay
37%7%13%18%17%5%
1758
16th to endDay
36%6%10%16%17%11%
1728
December1st to 15thDay
48%5%12%14%14%4
1620
16th to endDay
47%6%10%15%12%6%
1728
January1st to 15thNight
46%47%14%17%9%
2327
16th to endNight
40%5%9%17%15%11%
2413
February1st to 15thNight
36%5%11%14%18%13%
2112
16th to endNight
36%5%9%18%22%8%
1846
March1st to 15thNight
39%5%11%16%18%9%
1980
16th to endNight
33%5%12%18%20%9%
2112
April1st to 15thNight
38%6%12%17%17%7%
1977
16th to endNight
40%7%11%19%12%8%
1875
May1st to 15thNight
35%7%15%21%11%8%
1638
16th to endNight
30%8%20%24%14%1
1685
June1st to 15thNight
23%7%18%29%19%1
1620
16th to endNight
30%9%23%28%9%
1620
July1st to 15thNight
31%9%24%28%5%
1530
16th to endNight
21%10%34%29%4
1594
August1st to 15thNight
14%7%30%42%5%
1661
16th to endNight
29%12%25%24%6%1
2048
September1st to 15thNight
34%10%21%21%8%2
1980
16th to endNight
36%9%14%21%14%3
1837
October1st to 15thNight
24%7%13%25%19%9%
1842
16th to endNight
27%48%21%26%11%
2112
November1st to 15thNight
34%7%13%19%17%6%
2100
16th to endNight
33%410%19%15%14%
2229
December1st to 15thNight
47%5%10%17%13%5%
2340
16th to endNight
45%5%10%14%14%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
22%323%28%21%1
90
16th to endDay
17%6%26%32%15%2
96
February1st to 15thDay
7%218%44%22%4
90
16th to endDay
9%23%49%17%
81
March1st to 15thDay
26%213%36%21%
90
16th to endDay
9%321%48%16%
96
April1st to 15thDay
8%120%44%24%1
90
16th to endDay
11%10%19%30%23%4
195
May1st to 15thDay
10%14%16%43%14%
446
16th to endDay
5%13%11%38%28%2
517
June1st to 15thDay
312%313%55%11%
495
16th to endDay
5%12%115%44%20%
495
July1st to 15thDay
48%114%47%23%
475
16th to endDay
412%443%34%
515
August1st to 15thDay
16%244%43%
439
16th to endDay
14%219%32%39%
194
September1st to 15thDay
8%114%48%25%
135
16th to endDay
5%8%44%41%
93
October1st to 15thDay
312%60%24%
90
16th to endDay
16%8%22%47%4
96
November1st to 15thDay
27%10%28%28%4
90
16th to endDay
23%113%37%16%7%
90
December1st to 15thDay
35%112%21%27%2
90
16th to endDay
27%320%31%14%3
96
January1st to 15thNight
23%20%14%29%12%
900
16th to endNight
12%19%18%32%15%
877
February1st to 15thNight
16%20%14%32%14%1
704
16th to endNight
15%19%14%35%13%
584
March1st to 15thNight
16%20%16%30%15%
540
16th to endNight
10%19%13%38%16%1
576
April1st to 15thNight
11%18%17%38%14%
539
16th to endNight
14%19%17%32%15%
540
May1st to 15thNight
10%18%14%39%16%
540
16th to endNight
5%17%11%35%28%2
563
June1st to 15thNight
216%120%53%5%
540
16th to endNight
5%16%217%44%13%
540
July1st to 15thNight
5%11%115%46%19%
510
16th to endNight
216%6%51%21%
564
August1st to 15thNight
9%254%32%
539
16th to endNight
6%8%10%43%30%
573
September1st to 15thNight
8%8%19%47%24%
540
16th to endNight
9%9%313%43%20%
498
October1st to 15thNight
49%5%18%49%12%
522
16th to endNight
8%10%6%30%36%7%
704
November1st to 15thNight
11%15%10%25%32%4
700
16th to endNight
13%18%14%26%24%3
789
December1st to 15thNight
19%19%12%25%19%2
900
16th to endNight
19%21%18%25%12%2
960
Page generated at 2017-09-18 07:38:23. Version ac04

Copyright 2017 A. Danko


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