Okie-Tex Star Party
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Okie-Tex Star Party clear sky chart from 2005-11-05 to 2017-05-01.

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
50%
15404
31%
45613
18%
15359
62%
15359
45%
23645

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
49%
900
31%
2506
18%
895
59%
895
49%
1294
January16th to endNight
52%
825
38%
2515
24%
825
66%
825
49%
1223
February1st to 15thNight
40%
704
30%
2112
15%
700
54%
700
42%
1117
February16th to endNight
35%
632
37%
1894
13%
632
58%
632
43%
974
March1st to 15thNight
41%
720
30%
2160
14%
720
54%
720
44%
1105
March16th to endNight
35%
614
33%
2012
14%
614
57%
614
44%
974
April1st to 15thNight
30%
539
29%
1798
13%
539
51%
539
37%
904
April16th to endNight
37%
540
25%
1800
15%
540
54%
540
36%
938
May1st to 15thNight
40%
498
29%
1506
17%
498
58%
498
40%
802
May16th to endNight
40%
513
22%
1517
10%
513
54%
513
41%
821
June1st to 15thNight
46%
495
24%
1320
13%
495
55%
495
49%
709
June16th to endNight
56%
495
24%
1320
15%
495
63%
495
49%
712
July1st to 15thNight
69%
465
25%
1240
16%
465
74%
465
47%
689
July16th to endNight
66%
522
22%
1344
19%
489
67%
489
43%
759
August1st to 15thNight
69%
494
17%
1639
18%
491
72%
491
33%
935
August16th to endNight
67%
525
23%
1750
25%
525
70%
525
35%
951
September1st to 15thNight
61%
495
27%
1672
24%
495
69%
495
36%
895
September16th to endNight
58%
492
37%
1815
31%
492
71%
492
48%
797
October1st to 15thNight
50%
528
36%
1848
25%
528
63%
528
41%
903
October16th to endNight
60%
773
39%
2181
21%
773
69%
773
60%
1027
November1st to 15thNight
59%
875
38%
2275
18%
875
68%
875
61%
1128
November16th to endNight
54%
900
39%
2340
20%
900
64%
900
54%
1213
December1st to 15thNight
49%
900
33%
2361
16%
900
60%
900
49%
1278
December16th to endNight
43%
960
33%
2688
17%
960
55%
960
41%
1497

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
5%31332345%7%59%
46158
Night
5%31332335%7%60%
45791
Cloud CoverDay
5%31332345%7%59%
46156
Night
5%31332335%7%60%
45791
TransparencyDay
23%39%24%25%12%
45839
Night
23%310%24%25%12%
45613
SeeingDay
8%7%26%33%18%4
5118
Night
7%5%32%39%13%1
15406

By Month

Percentage Cloud Cover SW (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
35%1422233466%
1432
16th to endDay
2413213346%66%
1719
February1st to 15thDay
35%35%42332460%
1750
16th to endDay
3423323447%61%
1580
March1st to 15thDay
3413223347%62%
1800
16th to endDay
7%5%13212346%60%
2208
April1st to 15thDay
6%31322335%7%59%
2150
16th to endDay
8%5%22313447%56%
2160
May1st to 15thDay
8%323323437%57%
2126
16th to endDay
431232445%9%59%
2242
June1st to 15thDay
411222447%10%57%
2310
16th to endDay
221321346%9%62%
2310
July1st to 15thDay
5%2134345%7%9%51%
2310
16th to endDay
5%212325%6%8%9%51%
2414
August1st to 15thDay
5%223336%6%6%12%46%
1980
16th to endDay
6%3134245%7%9%52%
2100
September1st to 15thDay
10%325%5%2435%7%49%
1958
16th to endDay
222324346%66%
1815
October1st to 15thDay
7%313212336%65%
1779
16th to endDay
42221223473%
1680
November1st to 15thDay
2212211336%71%
1583
16th to endDay
45%12212235%70%
1620
December1st to 15thDay
26%3421235%6%62%
1596
16th to endDay
6%6%23313235%59%
1536
January1st to 15thNight
341331344465%
2506
16th to endNight
3413222246%64%
2515
February1st to 15thNight
4434314347%57%
2102
16th to endNight
4412323446%61%
1894
March1st to 15thNight
4413323447%60%
2160
16th to endNight
5%413312346%63%
2012
April1st to 15thNight
6%41232435%7%57%
1798
16th to endNight
8%31332435%6%56%
1800
May1st to 15thNight
8%312223447%58%
1505
16th to endNight
6%2123245%5%7%56%
1515
June1st to 15thNight
311332445%10%59%
1320
16th to endNight
321232447%10%57%
1320
July1st to 15thNight
3213326%5%8%10%51%
1320
16th to endNight
6%21342448%11%49%
1444
August1st to 15thNight
6%3145%35%6%8%11%41%
1650
16th to endNight
7%3123345%6%9%51%
1750
September1st to 15thNight
9%41232336%10%51%
1672
16th to endNight
4212312345%67%
1815
October1st to 15thNight
8%31221323463%
1848
16th to endNight
422212345%72%
2181
November1st to 15thNight
1212213245%72%
2275
16th to endNight
4412313235%68%
2340
December1st to 15thNight
3413313346%63%
2361
16th to endNight
6%5%23413335%58%
2688

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
35%13222335%66%
1432
16th to endDay
3412213346%66%
1719
February1st to 15thDay
35%35%41343360%
1750
16th to endDay
3413313447%61%
1580
March1st to 15thDay
341322235%7%61%
1800
16th to endDay
6%413212347%59%
2206
April1st to 15thDay
6%31322245%7%60%
2150
16th to endDay
7%413323447%55%
2160
May1st to 15thDay
8%313324446%56%
2126
16th to endDay
4313324449%59%
2242
June1st to 15thDay
42122245%6%10%57%
2310
16th to endDay
221321336%10%61%
2310
July1st to 15thDay
5%2134346%7%9%51%
2310
16th to endDay
4212326%5%8%10%51%
2414
August1st to 15thDay
5%113426%7%8%11%46%
1980
16th to endDay
6%3134245%7%9%51%
2100
September1st to 15thDay
9%41443445%6%49%
1958
16th to endDay
312223346%66%
1815
October1st to 15thDay
6%313312346%64%
1779
16th to endDay
411121223474%
1680
November1st to 15thDay
2312212245%71%
1583
16th to endDay
4412212225%70%
1620
December1st to 15thDay
35%24312346%62%
1596
16th to endDay
6%6%24213345%59%
1536
January1st to 15thNight
341332334465%
2506
16th to endNight
3413222246%64%
2515
February1st to 15thNight
4434323348%57%
2102
16th to endNight
4413323446%61%
1894
March1st to 15thNight
45%13323346%61%
2160
16th to endNight
5%413212346%63%
2012
April1st to 15thNight
6%413224348%57%
1798
16th to endNight
8%42332345%6%57%
1800
May1st to 15thNight
8%31322335%6%58%
1505
16th to endNight
6%3133245%5%6%57%
1515
June1st to 15thNight
31332437%9%59%
1320
16th to endNight
321322447%9%57%
1320
July1st to 15thNight
3223326%5%8%10%51%
1320
16th to endNight
5%2144245%7%11%49%
1444
August1st to 15thNight
6%315%446%7%8%12%40%
1650
16th to endNight
6%3123345%6%9%51%
1750
September1st to 15thNight
9%41232435%10%51%
1672
16th to endNight
422313436%66%
1815
October1st to 15thNight
8%41222333464%
1848
16th to endNight
42121234472%
2181
November1st to 15thNight
1113213245%72%
2275
16th to endNight
4412212235%68%
2340
December1st to 15thNight
3424313346%63%
2361
16th to endNight
5%6%33323345%58%
2688

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
22%26%26%32%9%
1433
16th to endDay
20%16%30%30%11%
1719
February1st to 15thDay
29%28%25%24%10%
1751
16th to endDay
22%25%27%26%15%
1580
March1st to 15thDay
22%26%25%27%15%
1800
16th to endDay
25%27%24%27%12%
2208
April1st to 15thDay
23%37%25%25%14%
2150
16th to endDay
27%28%25%23%10%
2160
May1st to 15thDay
28%310%22%23%12%
2126
16th to endDay
22%5%13%21%23%13%
2246
June1st to 15thDay
20%414%23%23%12%
2310
16th to endDay
18%39%27%22%18%
2310
July1st to 15thDay
27%6%10%24%19%10%
2161
16th to endDay
24%6%15%27%20%5%
2251
August1st to 15thDay
27%6%19%24%14%7%
1967
16th to endDay
27%6%12%24%22%7%
2100
September1st to 15thDay
33%311%24%16%10%
1958
16th to endDay
18%27%24%31%15%
1815
October1st to 15thDay
21%28%18%34%13%
1779
16th to endDay
15%15%21%35%20%
1680
November1st to 15thDay
15%15%23%33%19%
1583
16th to endDay
19%1419%32%22%
1620
December1st to 15thDay
23%210%28%24%9%
1596
16th to endDay
27%28%25%27%8%
1536
January1st to 15thNight
22%27%29%29%9%
2506
16th to endNight
21%15%26%32%12%
2515
February1st to 15thNight
27%28%26%27%7%
2112
16th to endNight
23%3425%27%15%
1894
March1st to 15thNight
24%27%23%31%11%
2160
16th to endNight
22%29%24%24%16%
2012
April1st to 15thNight
25%38%26%23%13%
1798
16th to endNight
27%413%22%20%12%
1800
May1st to 15thNight
26%311%24%21%12%
1506
16th to endNight
25%5%17%15%18%17%
1517
June1st to 15thNight
20%5%18%24%17%14%
1320
16th to endNight
21%5%13%25%16%17%
1320
July1st to 15thNight
24%415%26%18%9%
1240
16th to endNight
27%420%25%16%4
1344
August1st to 15thNight
31%6%20%21%12%6%
1639
16th to endNight
27%7%12%27%18%6%
1750
September1st to 15thNight
28%5%17%25%15%8%
1672
16th to endNight
18%37%25%30%14%
1815
October1st to 15thNight
24%37%19%28%15%
1848
16th to endNight
15%25%22%34%20%
2181
November1st to 15thNight
15%26%22%31%22%
2275
16th to endNight
19%1420%31%21%
2340
December1st to 15thNight
23%28%29%28%7%
2361
16th to endNight
28%28%24%27%9%
2688

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
11%5%26%33%16%6%
90
16th to endDay
7%9%29%29%20%4
96
February1st to 15thDay
8%6%40%22%16%5%
90
16th to endDay
412%41%27%8%4
81
March1st to 15thDay
3343%33%15%1
90
16th to endDay
15%20%32%21%9%1
231
April1st to 15thDay
11%21%37%19%6%3
269
16th to endDay
15%20%38%22%3
270
May1st to 15thDay
10%13%31%28%14%1
383
16th to endDay
8%7%32%33%14%2
437
June1st to 15thDay
6%6%28%33%17%5%
420
16th to endDay
4325%33%26%7%
420
July1st to 15thDay
5%17%45%26%4
400
16th to endDay
5%211%38%34%7%
443
August1st to 15thDay
5%218%41%21%9%
255
16th to endDay
8%120%43%20%6%
268
September1st to 15thDay
9%223%41%17%6%
233
16th to endDay
4220%30%31%12%
90
October1st to 15thDay
8%5%16%32%24%12%
90
16th to endDay
5%134%34%18%6%
96
November1st to 15thDay
35%15%37%27%10%
90
16th to endDay
20%13%30%23%12%1
90
December1st to 15thDay
5%11%35%35%12%
90
16th to endDay
16%5%31%38%7%1
96
January1st to 15thNight
6%7%34%38%12%2
900
16th to endNight
5%5%33%41%12%
825
February1st to 15thNight
7%5%40%37%9%
704
16th to endNight
8%8%45%31%5%
632
March1st to 15thNight
6%8%39%35%8%
720
16th to endNight
7%10%43%30%7%
614
April1st to 15thNight
10%11%45%27%4
539
16th to endNight
11%8%40%33%6%
540
May1st to 15thNight
10%9%37%34%8%
498
16th to endNight
7%443%32%11%1
515
June1st to 15thNight
3440%41%9%
495
16th to endNight
3332%46%14%
495
July1st to 15thNight
4117%52%23%
465
16th to endNight
6%114%49%26%1
522
August1st to 15thNight
8%110%43%33%2
494
16th to endNight
8%116%45%25%2
525
September1st to 15thNight
12%119%49%16%
495
16th to endNight
4230%41%18%2
492
October1st to 15thNight
11%430%37%12%2
528
16th to endNight
5%327%41%17%3
773
November1st to 15thNight
3429%44%15%1
875
16th to endNight
6%6%29%41%13%2
900
December1st to 15thNight
5%7%33%40%11%1
900
16th to endNight
8%7%35%36%10%
960
Page generated at 2017-05-02 07:43:36. Version ac04

Copyright 2017 A. Danko


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