Goliad State Park & Historic Site
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Goliad State Park & Historic Site clear sky chart from 2005-11-05 to 2017-09-22.

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
53%
15327
23%
47013
17%
15282
58%
15282
31%
28114

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
39%
897
22%
2327
11%
895
45%
895
29%
1557
January16th to endNight
39%
891
24%
2427
10%
891
47%
891
30%
1561
February1st to 15thNight
38%
704
25%
2110
12%
699
47%
699
26%
1308
February16th to endNight
29%
602
24%
1864
9%
602
42%
602
26%
1132
March1st to 15thNight
36%
540
25%
1980
14%
540
50%
540
22%
1222
March16th to endNight
38%
576
22%
2112
17%
576
47%
576
26%
1204
April1st to 15thNight
32%
539
19%
1977
11%
539
45%
539
24%
1182
April16th to endNight
34%
540
21%
1843
16%
540
43%
540
21%
1180
May1st to 15thNight
37%
539
20%
1620
13%
539
46%
539
27%
1042
May16th to endNight
53%
563
22%
1684
20%
561
59%
561
30%
1042
June1st to 15thNight
73%
540
18%
1620
21%
540
75%
540
41%
891
June16th to endNight
72%
540
16%
1620
19%
540
73%
540
31%
998
July1st to 15thNight
75%
510
18%
1530
21%
510
76%
510
37%
881
July16th to endNight
85%
564
20%
1594
23%
531
86%
531
42%
872
August1st to 15thNight
91%
539
27%
1649
30%
536
91%
536
56%
777
August16th to endNight
78%
573
17%
2024
22%
573
79%
573
31%
1163
September1st to 15thNight
79%
540
18%
1980
22%
540
80%
540
31%
1111
September16th to endNight
71%
513
24%
1891
28%
513
73%
513
29%
1064
October1st to 15thNight
75%
522
33%
1842
33%
522
76%
522
40%
912
October16th to endNight
64%
704
35%
2112
26%
704
67%
704
46%
1084
November1st to 15thNight
55%
700
26%
2100
19%
700
58%
700
33%
1260
November16th to endNight
51%
831
30%
2271
17%
831
58%
831
39%
1318
December1st to 15thNight
40%
900
24%
2340
13%
900
44%
900
25%
1609
December16th to endNight
37%
960
19%
2496
10%
960
41%
960
25%
1744

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
11%5%25%5%35%5%6%8%39%
47859
Night
11%5%2442445%8%48%
47211
TransparencyDay
41%7%11%18%14%7%
47559
Night
34%5%13%20%15%9%
47016
SeeingDay
11%318%32%24%8%
5283
Night
14%421%35%21%2
15331

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
20%6%25%43335%5%37%
1611
16th to endDay
15%7%24423445%44%
1806
February1st to 15thDay
19%6%23324335%45%
1750
16th to endDay
17%7%3431334445%
1607
March1st to 15thDay
22%7%25%41435%6%37%
1980
16th to endDay
13%6%25%42446%7%42%
2110
April1st to 15thDay
12%7%25%5%2445%7%42%
1971
16th to endDay
15%7%36%424436%40%
2112
May1st to 15thDay
10%6%46%5%35%5%6%8%36%
2331
16th to endDay
9%5%35%5%46%5%7%10%35%
2430
June1st to 15thDay
4315%6%5%7%6%8%9%39%
2340
16th to endDay
7%437%7%48%7%8%10%29%
2340
July1st to 15thDay
9%5%35%6%46%7%6%10%32%
2340
16th to endDay
5%436%6%47%7%7%10%35%
2466
August1st to 15thDay
12145%45%7%8%12%45%
2298
16th to endDay
8%5%36%7%46%7%8%9%31%
2177
September1st to 15thDay
8%6%38%8%45%5%7%8%32%
1980
16th to endDay
8%5%25%7%36%6%7%8%37%
1881
October1st to 15thDay
7%3245%35%5%5%9%46%
1777
16th to endDay
8%323434446%55%
1760
November1st to 15thDay
10%6%26%6%46%5%6%8%38%
1758
16th to endDay
14%5%34423435%49%
1686
December1st to 15thDay
22%9%35%424246%34%
1620
16th to endDay
17%7%35%5%34446%36%
1728
January1st to 15thNight
21%5%24313345%44%
2327
16th to endNight
17%424323446%46%
2427
February1st to 15thNight
16%5%24423345%46%
2102
16th to endNight
14%6%24333345%48%
1864
March1st to 15thNight
19%7%24324345%42%
1980
16th to endNight
13%6%24313346%49%
2112
April1st to 15thNight
12%5%25%3345%5%8%42%
1977
16th to endNight
16%7%35%424348%38%
1843
May1st to 15thNight
9%5%345%35%46%10%39%
1619
16th to endNight
8%4245%346%6%12%41%
1683
June1st to 15thNight
4213425%5%5%10%53%
1620
16th to endNight
7%313436%6%7%12%43%
1620
July1st to 15thNight
43245%25%47%11%48%
1620
16th to endNight
22124245%6%13%53%
1702
August1st to 15thNight
11111346%11%63%
1659
16th to endNight
5%4244335%6%11%47%
2024
September1st to 15thNight
6%3244235%6%10%49%
1980
16th to endNight
8%415%42446%8%48%
1891
October1st to 15thNight
5%413323446%60%
1842
16th to endNight
7%313312225%65%
2112
November1st to 15thNight
10%6%2442445%6%49%
2100
16th to endNight
11%413322346%55%
2271
December1st to 15thNight
20%7%24424336%40%
2340
16th to endNight
18%9%26%323345%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
49%35%12%15%13%
1612
16th to endDay
41%36%15%19%12%
1806
February1st to 15thDay
41%37%13%18%15%
1751
16th to endDay
42%36%16%18%11%
1607
March1st to 15thDay
47%48%12%18%9%
1980
16th to endDay
39%6%9%15%17%11%
2112
April1st to 15thDay
40%6%8%14%18%11%
1971
16th to endDay
45%5%7%17%14%10%
2112
May1st to 15thDay
42%6%12%17%13%8%
2331
16th to endDay
41%8%12%17%16%3
2434
June1st to 15thDay
34%8%12%21%18%3
2340
16th to endDay
46%8%12%22%10%
2340
July1st to 15thDay
42%9%15%21%10%
2201
16th to endDay
36%10%20%28%4
2311
August1st to 15thDay
28%9%20%32%8%
2284
16th to endDay
43%12%17%20%5%1
2177
September1st to 15thDay
46%9%12%16%12%2
1980
16th to endDay
40%8%12%16%15%6%
1881
October1st to 15thDay
32%7%10%20%17%11%
1777
16th to endDay
29%6%5%16%25%17%
1760
November1st to 15thDay
42%7%9%13%16%10%
1758
16th to endDay
38%46%14%16%18%
1686
December1st to 15thDay
52%36%13%15%8%
1620
16th to endDay
48%48%14%15%8%
1728
January1st to 15thNight
42%37%14%17%14%
2327
16th to endNight
39%37%16%18%13%
2427
February1st to 15thNight
39%39%11%18%17%
2112
16th to endNight
38%47%17%19%12%
1864
March1st to 15thNight
42%48%14%17%11%
1980
16th to endNight
36%412%16%17%12%
2112
April1st to 15thNight
38%5%11%16%15%11%
1977
16th to endNight
45%410%16%13%10%
1843
May1st to 15thNight
38%7%14%17%12%10%
1620
16th to endNight
34%8%16%23%14%1
1685
June1st to 15thNight
25%6%17%26%21%2
1620
16th to endNight
31%10%18%28%10%
1620
July1st to 15thNight
27%8%24%32%6%
1530
16th to endNight
20%10%32%32%4
1594
August1st to 15thNight
13%6%28%43%6%
1649
16th to endNight
28%11%28%25%5%
2024
September1st to 15thNight
29%8%22%22%13%3
1980
16th to endNight
32%7%14%24%15%5%
1891
October1st to 15thNight
23%5%12%27%19%12%
1842
16th to endNight
23%36%19%28%18%
2112
November1st to 15thNight
34%5%13%19%18%9%
2100
16th to endNight
30%311%16%17%20%
2271
December1st to 15thNight
45%47%17%15%9%
2340
16th to endNight
46%47%14%16%11%
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
18%334%37%41
90
16th to endDay
16%8%41%22%10%
96
February1st to 15thDay
10%11%36%26%15%
90
16th to endDay
17%6%40%24%11%
81
March1st to 15thDay
32%8%27%22%8%
90
16th to endDay
14%11%31%30%12%
96
April1st to 15thDay
15%12%31%32%8%
90
16th to endDay
19%7%38%22%12%
222
May1st to 15thDay
14%10%42%25%7%
468
16th to endDay
11%433%32%15%1
517
June1st to 15thDay
5%13%41%32%7%
495
16th to endDay
10%110%36%30%11%
495
July1st to 15thDay
6%18%36%34%12%
475
16th to endDay
5%1335%38%16%
515
August1st to 15thDay
2335%35%21%
451
16th to endDay
12%16%36%23%18%
217
September1st to 15thDay
7%228%41%20%
135
16th to endDay
2317%49%26%
108
October1st to 15thDay
1337%44%13%
90
16th to endDay
15%210%39%27%5%
96
November1st to 15thDay
16%326%33%17%2
90
16th to endDay
27%7%24%25%7%6%
90
December1st to 15thDay
41%215%20%14%6%
90
16th to endDay
29%14%33%14%6%2
96
January1st to 15thNight
24%7%24%32%11%
900
16th to endNight
20%6%29%35%7%
891
February1st to 15thNight
20%9%28%34%7%
704
16th to endNight
18%8%39%27%6%
602
March1st to 15thNight
23%5%29%34%6%
540
16th to endNight
15%9%32%35%7%
576
April1st to 15thNight
15%6%41%30%6%
539
16th to endNight
18%7%36%29%7%
540
May1st to 15thNight
13%6%38%36%4
540
16th to endNight
9%229%41%16%
563
June1st to 15thNight
6%12%52%26%1
540
16th to endNight
8%10%43%34%2
540
July1st to 15thNight
5%7%41%41%4
510
16th to endNight
3340%46%6%
564
August1st to 15thNight
1240%49%6%
539
16th to endNight
7%430%52%6%
573
September1st to 15thNight
8%1227%52%7%
540
16th to endNight
10%7%30%43%7%
513
October1st to 15thNight
7%110%39%37%3
522
16th to endNight
8%320%40%25%2
704
November1st to 15thNight
14%322%37%20%2
700
16th to endNight
14%425%33%19%2
831
December1st to 15thNight
24%6%24%30%13%1
900
16th to endNight
22%8%25%30%11%1
960
Page generated at 2017-09-23 05:43:40. Version ac04

Copyright 2017 A. Danko


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