Balmorhea State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Balmorhea State Park clear sky chart from 2005-11-05 to 2018-11-30.

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
63%
17023
33%
51876
24%
16982
72%
16982
46%
25964

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
53%
777
36%
2328
22%
776
66%
776
43%
1207
January16th to endNight
55%
832
39%
2496
25%
832
69%
832
46%
1246
February1st to 15thNight
56%
762
36%
2289
23%
759
69%
759
48%
1110
February16th to endNight
44%
684
34%
2050
18%
684
59%
684
47%
1011
March1st to 15thNight
52%
780
33%
2332
20%
780
63%
780
44%
1168
March16th to endNight
51%
697
37%
2153
23%
697
65%
697
49%
1027
April1st to 15thNight
48%
584
36%
1948
21%
584
67%
584
44%
904
April16th to endNight
53%
579
37%
1929
26%
579
70%
579
54%
808
May1st to 15thNight
51%
584
31%
1949
25%
584
65%
584
47%
898
May16th to endNight
60%
610
29%
1878
25%
609
70%
609
46%
941
June1st to 15thNight
68%
585
30%
1755
24%
585
77%
585
54%
841
June16th to endNight
75%
585
26%
1755
25%
585
79%
585
48%
883
July1st to 15thNight
79%
555
22%
1792
24%
555
81%
555
42%
935
July16th to endNight
84%
612
26%
1931
29%
579
86%
579
41%
990
August1st to 15thNight
84%
575
28%
1908
34%
572
86%
572
46%
937
August16th to endNight
83%
621
23%
2070
27%
621
84%
621
36%
1136
September1st to 15thNight
78%
585
24%
1966
27%
585
79%
585
34%
1102
September16th to endNight
73%
582
27%
2145
29%
582
74%
582
32%
1171
October1st to 15thNight
71%
601
35%
2161
34%
601
75%
601
43%
1018
October16th to endNight
72%
832
38%
2496
27%
832
78%
832
55%
1179
November1st to 15thNight
67%
943
38%
2583
23%
943
73%
943
59%
1258
November16th to endNight
66%
1050
38%
2730
22%
1050
74%
1050
55%
1400
December1st to 15thNight
60%
975
37%
2535
21%
975
67%
975
50%
1368
December16th to endNight
52%
1033
37%
2697
19%
1033
64%
1033
50%
1426

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%21232445%7%60%
52392
Night
421232345%7%62%
52099
Cloud CoverDay
5%21232445%7%60%
52390
Night
5%21222345%7%62%
52099
TransparencyDay
23%5%8%16%24%21%
52112
Night
20%48%17%25%23%
51881
SeeingDay
6%5%20%32%27%8%
6817
Night
6%421%39%25%2
17030

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
5%5%13322246%61%
1940
16th to endDay
4312213336%67%
2080
February1st to 15thDay
2313214345%67%
1900
16th to endDay
2412223245%68%
1710
March1st to 15thDay
5%41322446%6%59%
1954
16th to endDay
4311213346%66%
2421
April1st to 15thDay
3112323347%66%
2330
16th to endDay
311212235%73%
2306
May1st to 15thDay
5%112324446%64%
2331
16th to endDay
5%111135%6%6%64%
2586
June1st to 15thDay
11221446%8%65%
2535
16th to endDay
4212425%5%6%8%55%
2535
July1st to 15thDay
7%2145%35%5%8%10%47%
2393
16th to endDay
42135%36%7%8%10%46%
2469
August1st to 15thDay
3213437%7%8%10%46%
2294
16th to endDay
43246%46%7%8%9%42%
2484
September1st to 15thDay
13%3145%346%7%8%40%
2324
16th to endDay
12%3134335%5%6%49%
2145
October1st to 15thDay
5%21341335%6%60%
2126
16th to endDay
5%21221322371%
2080
November1st to 15thDay
6%2221133470%
1921
16th to endDay
5%21112235%71%
1885
December1st to 15thDay
5%5%1221335%5%64%
1755
16th to endDay
45%12212446%64%
1888
January1st to 15thNight
6%412313335%62%
2328
16th to endNight
5%312213246%65%
2496
February1st to 15thNight
3313212336%66%
2282
16th to endNight
5%312213445%66%
2050
March1st to 15thNight
431331335%6%63%
2332
16th to endNight
4312213345%67%
2153
April1st to 15thNight
4212223346%66%
1948
16th to endNight
22223345%72%
1929
May1st to 15thNight
4212213346%66%
1949
16th to endNight
42122135%6%7%61%
1877
June1st to 15thNight
11232347%10%62%
1755
16th to endNight
31123245%7%11%57%
1755
July1st to 15thNight
42123245%6%12%53%
1892
16th to endNight
21134245%8%12%54%
2051
August1st to 15thNight
22133235%7%15%52%
1919
16th to endNight
3213436%6%8%13%47%
2070
September1st to 15thNight
8%3133235%8%11%48%
1966
16th to endNight
8%3144245%7%8%49%
2145
October1st to 15thNight
7%112212347%63%
2161
16th to endNight
5%211212335%70%
2496
November1st to 15thNight
4212212225%71%
2583
16th to endNight
4212213235%70%
2730
December1st to 15thNight
5%311212446%63%
2535
16th to endNight
4312223346%65%
2697

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
6%5%13222336%61%
1940
16th to endDay
5%312213335%67%
2080
February1st to 15thDay
2313114335%67%
1900
16th to endDay
2312223345%69%
1710
March1st to 15thDay
5%41222445%7%59%
1954
16th to endDay
421121325%6%66%
2419
April1st to 15thDay
3112224347%67%
2330
16th to endDay
311212235%73%
2306
May1st to 15thDay
5%212224346%65%
2331
16th to endDay
5%111235%6%6%64%
2586
June1st to 15thDay
11122446%7%67%
2535
16th to endDay
4212325%5%6%8%56%
2535
July1st to 15thDay
7%214435%47%9%48%
2393
16th to endDay
4213435%7%8%10%47%
2469
August1st to 15thDay
3113437%7%7%11%47%
2294
16th to endDay
43146%36%7%7%9%44%
2484
September1st to 15thDay
14%3145%346%6%8%41%
2324
16th to endDay
12%3144345%5%6%49%
2145
October1st to 15thDay
5%213323447%60%
2126
16th to endDay
6%2221322372%
2080
November1st to 15thDay
6%21112235%70%
1921
16th to endDay
5%21112235%71%
1885
December1st to 15thDay
5%412213346%64%
1755
16th to endDay
45%12212446%64%
1888
January1st to 15thNight
6%413312346%62%
2328
16th to endNight
6%312213336%65%
2496
February1st to 15thNight
3313212336%66%
2282
16th to endNight
5%212213345%66%
2050
March1st to 15thNight
431231335%6%63%
2332
16th to endNight
5%212213345%67%
2153
April1st to 15thNight
4112223346%66%
1948
16th to endNight
2122324472%
1929
May1st to 15thNight
5%212213346%66%
1949
16th to endNight
42122135%6%7%62%
1877
June1st to 15thNight
1232347%10%63%
1755
16th to endNight
31122245%7%11%57%
1755
July1st to 15thNight
42123245%6%11%54%
1892
16th to endNight
21133335%7%12%54%
2051
August1st to 15thNight
21133235%6%15%52%
1919
16th to endNight
3213425%6%8%13%47%
2070
September1st to 15thNight
8%3143245%7%11%48%
1966
16th to endNight
8%3143245%7%8%49%
2145
October1st to 15thNight
7%1222235%6%63%
2161
16th to endNight
5%21212235%70%
2496
November1st to 15thNight
5%22212225%71%
2583
16th to endNight
421221223470%
2730
December1st to 15thNight
6%311212446%64%
2535
16th to endNight
4312223445%65%
2697

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
25%25%16%31%17%
1941
16th to endDay
19%35%14%31%25%
2080
February1st to 15thDay
19%27%14%25%30%
1901
16th to endDay
18%3410%30%32%
1710
March1st to 15thDay
24%35%14%25%26%
1954
16th to endDay
18%36%11%27%33%
2421
April1st to 15thDay
18%36%8%27%34%
2330
16th to endDay
14%25%10%28%38%
2306
May1st to 15thDay
21%35%10%23%35%
2331
16th to endDay
17%5%9%14%21%31%
2589
June1st to 15thDay
14%5%10%16%25%26%
2535
16th to endDay
24%5%9%18%23%18%
2535
July1st to 15thDay
29%9%14%23%16%5%
2264
16th to endDay
28%9%14%26%16%4
2326
August1st to 15thDay
27%10%15%24%20%2
2281
16th to endDay
34%10%14%21%14%4
2484
September1st to 15thDay
38%9%12%15%15%6%
2324
16th to endDay
34%7%9%16%23%8%
2145
October1st to 15thDay
24%5%8%20%22%18%
2126
16th to endDay
19%2412%30%29%
2080
November1st to 15thDay
18%36%21%28%22%
1921
16th to endDay
17%25%15%28%30%
1885
December1st to 15thDay
21%35%18%31%18%
1755
16th to endDay
21%26%21%30%17%
1888
January1st to 15thNight
24%35%13%32%20%
2328
16th to endNight
21%3412%31%26%
2496
February1st to 15thNight
19%26%10%24%35%
2292
16th to endNight
20%36%9%25%35%
2050
March1st to 15thNight
21%35%13%24%30%
2332
16th to endNight
19%26%11%25%33%
2153
April1st to 15thNight
19%36%9%24%35%
1948
16th to endNight
14%28%13%22%38%
1929
May1st to 15thNight
19%36%12%22%34%
1950
16th to endNight
20%6%9%16%19%27%
1879
June1st to 15thNight
16%5%9%21%26%20%
1755
16th to endNight
19%5%13%20%20%20%
1755
July1st to 15thNight
22%7%15%29%19%4
1792
16th to endNight
20%9%13%30%21%4
1931
August1st to 15thNight
19%7%18%27%25%2
1908
16th to endNight
24%10%15%27%17%4
2070
September1st to 15thNight
28%8%16%24%13%8%
1966
16th to endNight
30%6%11%20%22%9%
2145
October1st to 15thNight
21%5%10%22%18%21%
2161
16th to endNight
17%25%12%28%32%
2496
November1st to 15thNight
17%25%18%32%24%
2583
16th to endNight
19%1412%30%32%
2730
December1st to 15thNight
20%46%17%26%23%
2535
16th to endNight
20%26%16%32%20%
2697

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%6%28%31%22%
135
16th to endDay
6%15%27%29%15%5%
144
February1st to 15thDay
48%19%35%27%4
135
16th to endDay
7%16%28%33%11%2
120
March1st to 15thDay
39%38%33%13%2
139
16th to endDay
415%40%28%8%3
352
April1st to 15thDay
7%13%41%30%5%1
329
16th to endDay
5%17%38%30%7%
318
May1st to 15thDay
6%12%39%30%10%
348
16th to endDay
6%329%42%18%
545
June1st to 15thDay
114%45%33%4
570
16th to endDay
319%40%36%9%
570
July1st to 15thDay
5%7%27%40%18%
418
16th to endDay
4426%42%21%
391
August1st to 15thDay
4323%46%21%
359
16th to endDay
6%6%24%43%18%
396
September1st to 15thDay
10%6%32%38%12%
359
16th to endDay
19%10%29%27%13%
180
October1st to 15thDay
12%17%25%30%13%
180
16th to endDay
11%116%26%29%15%
192
November1st to 15thDay
12%421%31%23%7%
180
16th to endDay
8%10%24%25%25%5%
178
December1st to 15thDay
11%7%20%37%21%1
135
16th to endDay
8%7%31%36%14%
144
January1st to 15thNight
8%5%27%38%16%3
780
16th to endNight
7%7%26%37%18%1
832
February1st to 15thNight
6%8%25%37%21%1
764
16th to endNight
7%8%37%37%9%
684
March1st to 15thNight
7%9%26%37%16%1
780
16th to endNight
6%7%32%38%14%1
697
April1st to 15thNight
5%8%36%40%9%
584
16th to endNight
28%33%43%11%
579
May1st to 15thNight
6%5%34%43%10%
585
16th to endNight
5%228%45%17%
611
June1st to 15thNight
26%52%19%
585
16th to endNight
317%52%24%1
585
July1st to 15thNight
49%44%38%2
555
16th to endNight
25%42%44%4
612
August1st to 15thNight
3330%59%3
575
16th to endNight
3429%55%6%
621
September1st to 15thNight
9%333%46%7%
585
16th to endNight
10%8%37%38%3
582
October1st to 15thNight
9%113%42%30%3
601
16th to endNight
7%214%35%31%8%
832
November1st to 15thNight
6%120%36%28%5%
943
16th to endNight
5%5%18%38%28%3
1050
December1st to 15thNight
7%5%23%41%19%2
975
16th to endNight
6%8%28%40%13%2
1033
Page generated at 2018-12-01 10:35:34. Version ac04

Copyright 2018 A. Danko


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