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 2018-02-22.

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
50%
16508
31%
48844
18%
16463
62%
16463
45%
25355

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%
975
31%
2716
18%
970
60%
970
49%
1400
January16th to endNight
53%
893
39%
2724
25%
893
68%
893
51%
1294
February1st to 15thNight
40%
764
30%
2292
15%
760
54%
760
41%
1221
February16th to endNight
34%
660
38%
1978
13%
660
57%
660
42%
1027
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
41%
540
28%
1632
16%
540
57%
540
40%
872
May16th to endNight
41%
561
23%
1659
11%
561
55%
561
41%
899
June1st to 15thNight
48%
540
23%
1440
12%
540
56%
540
49%
777
June16th to endNight
55%
540
25%
1440
15%
540
63%
540
47%
788
July1st to 15thNight
69%
510
23%
1360
16%
510
74%
510
47%
758
July16th to endNight
66%
564
22%
1460
18%
531
67%
531
42%
836
August1st to 15thNight
68%
539
16%
1789
16%
536
70%
536
31%
1045
August16th to endNight
67%
573
25%
1910
28%
573
71%
573
36%
1029
September1st to 15thNight
63%
540
26%
1824
24%
540
71%
540
38%
959
September16th to endNight
56%
537
37%
1980
30%
537
70%
537
45%
902
October1st to 15thNight
48%
576
35%
2016
23%
576
62%
576
41%
979
October16th to endNight
60%
843
40%
2379
22%
843
69%
843
60%
1120
November1st to 15thNight
58%
950
37%
2470
18%
950
67%
950
61%
1233
November16th to endNight
54%
975
41%
2535
21%
975
64%
975
55%
1303
December1st to 15thNight
50%
975
33%
2558
17%
975
60%
975
49%
1378
December16th to endNight
43%
1040
33%
2912
18%
1040
55%
1040
42%
1614

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%
49419
Night
5%31332335%7%60%
49022
Cloud CoverDay
5%31332345%7%59%
49417
Night
5%31332335%7%60%
49022
TransparencyDay
23%39%24%25%12%
49100
Night
23%310%24%25%12%
48844
SeeingDay
8%7%26%33%19%5%
6226
Night
7%5%32%39%13%1
16510

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%13222335%66%
1552
16th to endDay
2412213346%67%
1862
February1st to 15thDay
35%35%42333460%
1900
16th to endDay
3423323447%60%
1642
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%323424437%56%
2319
16th to endDay
431231445%9%58%
2452
June1st to 15thDay
411222447%10%58%
2520
16th to endDay
221321346%9%62%
2520
July1st to 15thDay
5%2134345%7%9%52%
2520
16th to endDay
5%212325%6%8%9%51%
2606
August1st to 15thDay
5%223436%6%7%12%45%
2160
16th to endDay
6%3134245%7%9%52%
2292
September1st to 15thDay
9%31442335%7%51%
2136
16th to endDay
5%22324346%63%
1980
October1st to 15thDay
7%312212236%66%
1941
16th to endDay
42221223473%
1833
November1st to 15thDay
2213211336%70%
1718
16th to endDay
441221223470%
1755
December1st to 15thDay
25%23212346%64%
1729
16th to endDay
5%5%24323345%60%
1664
January1st to 15thNight
3412313445%65%
2716
16th to endNight
3412212246%67%
2724
February1st to 15thNight
4434314347%57%
2282
16th to endNight
5%412323446%60%
1978
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%57%
1631
16th to endNight
6%3123245%5%7%56%
1657
June1st to 15thNight
311332445%10%59%
1440
16th to endNight
321232447%10%56%
1440
July1st to 15thNight
3213326%5%8%11%51%
1440
16th to endNight
6%31342448%11%48%
1560
August1st to 15thNight
7%415%5%45%6%8%11%39%
1800
16th to endNight
6%3123345%5%9%52%
1910
September1st to 15thNight
8%41232336%10%52%
1824
16th to endNight
5%212312445%65%
1980
October1st to 15thNight
8%31221323464%
2016
16th to endNight
422212345%72%
2379
November1st to 15thNight
2212213246%71%
2470
16th to endNight
3412213235%68%
2535
December1st to 15thNight
2413323346%63%
2558
16th to endNight
5%5%23413335%59%
2912

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%
1552
16th to endDay
2412213336%67%
1862
February1st to 15thDay
3435%41343460%
1900
16th to endDay
35%13323447%60%
1642
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%31332435%6%56%
2319
16th to endDay
431232345%9%59%
2452
June1st to 15thDay
42122245%6%10%57%
2520
16th to endDay
321231346%9%61%
2520
July1st to 15thDay
5%2134346%7%8%52%
2520
16th to endDay
4212326%6%8%10%51%
2606
August1st to 15thDay
5%2145%36%6%8%11%45%
2160
16th to endDay
6%3134245%6%9%52%
2292
September1st to 15thDay
9%31443345%7%51%
2136
16th to endDay
5%22223346%63%
1980
October1st to 15thDay
7%31332345%65%
1941
16th to endDay
41221223473%
1833
November1st to 15thDay
2313212245%70%
1718
16th to endDay
4412212225%70%
1755
December1st to 15thDay
35%24212346%64%
1729
16th to endDay
5%5%24213345%60%
1664
January1st to 15thNight
3413323345%64%
2716
16th to endNight
3413222246%66%
2724
February1st to 15thNight
4434323348%56%
2282
16th to endNight
4413323446%60%
1978
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%31322435%6%57%
1631
16th to endNight
6%3133245%5%6%57%
1657
June1st to 15thNight
22332436%9%59%
1440
16th to endNight
321322447%9%56%
1440
July1st to 15thNight
3222426%5%8%10%50%
1440
16th to endNight
6%215%4245%7%11%48%
1560
August1st to 15thNight
7%325%446%7%8%12%38%
1800
16th to endNight
6%3123345%6%9%52%
1910
September1st to 15thNight
9%41232435%10%52%
1824
16th to endNight
5%22313445%64%
1980
October1st to 15thNight
8%31221333464%
2016
16th to endNight
32121234472%
2379
November1st to 15thNight
1213213245%71%
2470
16th to endNight
3412212235%69%
2535
December1st to 15thNight
3324323346%63%
2558
16th to endNight
5%5%33323345%59%
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
21%27%26%32%9%
1553
16th to endDay
19%15%30%31%12%
1862
February1st to 15thDay
28%210%25%23%9%
1901
16th to endDay
23%25%26%26%15%
1642
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%39%23%23%11%
2319
16th to endDay
22%5%13%22%23%13%
2456
June1st to 15thDay
19%415%23%22%14%
2520
16th to endDay
18%39%26%22%18%
2520
July1st to 15thDay
27%6%10%24%20%10%
2371
16th to endDay
24%6%15%27%20%5%
2443
August1st to 15thDay
28%7%19%24%14%6%
2147
16th to endDay
26%6%11%24%22%8%
2292
September1st to 15thDay
31%310%26%17%10%
2136
16th to endDay
21%27%23%29%14%
1980
October1st to 15thDay
21%28%18%33%15%
1941
16th to endDay
15%15%21%36%19%
1833
November1st to 15thDay
16%25%24%33%18%
1718
16th to endDay
19%1420%32%22%
1755
December1st to 15thDay
22%29%28%25%10%
1729
16th to endDay
26%28%25%27%8%
1664
January1st to 15thNight
21%27%29%28%9%
2716
16th to endNight
20%15%25%33%13%
2724
February1st to 15thNight
27%29%26%26%7%
2292
16th to endNight
24%3425%27%14%
1978
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%410%25%21%11%
1632
16th to endNight
25%5%16%16%18%17%
1659
June1st to 15thNight
20%5%17%23%16%15%
1440
16th to endNight
22%5%12%25%17%16%
1440
July1st to 15thNight
24%415%25%19%9%
1360
16th to endNight
28%421%24%16%4
1460
August1st to 15thNight
32%7%21%20%12%6%
1789
16th to endNight
27%7%12%26%20%5%
1910
September1st to 15thNight
27%5%16%27%16%7%
1824
16th to endNight
20%37%23%29%14%
1980
October1st to 15thNight
24%38%18%28%16%
2016
16th to endNight
15%25%22%34%20%
2379
November1st to 15thNight
16%26%23%31%20%
2470
16th to endNight
19%1421%31%21%
2535
December1st to 15thNight
22%28%29%28%8%
2558
16th to endNight
27%27%23%27%10%
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
8%6%28%35%16%4
135
16th to endDay
5%9%23%34%20%6%
144
February1st to 15thDay
5%5%49%21%12%5%
135
16th to endDay
5%12%46%26%7%4
100
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%11%31%29%15%1
456
16th to endDay
9%7%33%33%13%2
517
June1st to 15thDay
6%6%27%33%19%6%
495
16th to endDay
4324%35%25%6%
495
July1st to 15thDay
5%15%42%27%8%
475
16th to endDay
6%19%36%36%9%
513
August1st to 15thDay
6%218%40%23%8%
315
16th to endDay
8%119%41%22%6%
332
September1st to 15thDay
7%120%39%19%10%
291
16th to endDay
14%320%28%24%8%
135
October1st to 15thDay
10%5%22%31%22%8%
135
16th to endDay
3434%31%16%9%
144
November1st to 15thDay
4425%35%23%6%
135
16th to endDay
15%12%28%24%15%3
135
December1st to 15thDay
5%9%35%31%13%3
135
16th to endDay
11%439%34%9%1
144
January1st to 15thNight
5%6%34%38%12%1
975
16th to endNight
5%5%32%41%13%1
893
February1st to 15thNight
6%5%41%36%9%
764
16th to endNight
8%8%45%30%5%
660
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%8%36%35%8%
540
16th to endNight
7%443%31%11%1
563
June1st to 15thNight
3438%42%10%
540
16th to endNight
3332%46%13%
540
July1st to 15thNight
4117%51%23%
510
16th to endNight
6%113%49%26%1
564
August1st to 15thNight
9%111%43%32%1
539
16th to endNight
7%115%46%26%2
573
September1st to 15thNight
11%118%49%18%
540
16th to endNight
5%230%40%17%2
537
October1st to 15thNight
11%5%32%37%11%2
576
16th to endNight
4428%41%17%3
843
November1st to 15thNight
3430%43%15%2
950
16th to endNight
6%6%29%40%13%2
975
December1st to 15thNight
47%33%40%12%1
975
16th to endNight
8%7%36%36%10%
1040
Page generated at 2018-02-23 10:21:29. Version ac04

Copyright 2018 A. Danko


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