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 2017-09-20.

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
62%
15447
33%
47079
24%
15406
71%
15406
46%
23562

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
52%
717
35%
2148
21%
716
65%
716
42%
1122
January16th to endNight
52%
768
39%
2304
24%
768
67%
768
45%
1163
February1st to 15thNight
55%
702
36%
2109
22%
699
68%
699
48%
1023
February16th to endNight
43%
632
35%
1894
18%
632
59%
632
48%
923
March1st to 15thNight
52%
720
34%
2153
21%
720
63%
720
44%
1075
March16th to endNight
51%
643
38%
1987
23%
643
66%
643
50%
937
April1st to 15thNight
47%
539
35%
1798
20%
539
65%
539
43%
846
April16th to endNight
51%
540
37%
1800
26%
540
69%
540
54%
753
May1st to 15thNight
51%
539
30%
1799
24%
539
65%
539
46%
836
May16th to endNight
59%
562
28%
1730
24%
561
69%
561
44%
882
June1st to 15thNight
67%
540
28%
1620
23%
540
76%
540
54%
775
June16th to endNight
75%
540
27%
1620
26%
540
79%
540
48%
816
July1st to 15thNight
79%
510
22%
1646
25%
510
81%
510
43%
845
July16th to endNight
84%
564
26%
1771
29%
531
85%
531
40%
921
August1st to 15thNight
85%
539
26%
1789
33%
536
86%
536
45%
885
August16th to endNight
83%
573
24%
1910
28%
573
83%
573
35%
1061
September1st to 15thNight
78%
540
22%
1815
25%
540
78%
540
34%
1020
September16th to endNight
75%
507
28%
1870
31%
507
77%
507
32%
1007
October1st to 15thNight
72%
509
36%
1829
36%
509
76%
509
44%
846
October16th to endNight
74%
704
39%
2112
28%
704
80%
704
59%
962
November1st to 15thNight
66%
805
38%
2205
23%
805
72%
805
60%
1063
November16th to endNight
64%
900
38%
2340
20%
900
72%
900
53%
1225
December1st to 15thNight
59%
900
37%
2340
21%
900
67%
900
51%
1251
December16th to endNight
51%
954
36%
2490
18%
954
62%
954
50%
1325

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%
47727
Night
421232345%7%62%
47302
Cloud CoverDay
5%21232445%7%60%
47725
Night
421222345%7%62%
47302
TransparencyDay
23%5%8%16%24%21%
47447
Night
20%48%17%24%23%
47084
SeeingDay
6%5%20%33%26%7%
5307
Night
5%422%39%25%2
15454

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%23322345%61%
1790
16th to endDay
5%312213346%65%
1920
February1st to 15thDay
2313214335%68%
1750
16th to endDay
2412212245%70%
1580
March1st to 15thDay
5%41322345%6%60%
1804
16th to endDay
4211213346%67%
2235
April1st to 15thDay
3112323347%66%
2150
16th to endDay
311212235%74%
2160
May1st to 15thDay
5%112224346%65%
2151
16th to endDay
5%211135%6%6%63%
2382
June1st to 15thDay
1221346%8%67%
2340
16th to endDay
4212425%6%6%8%54%
2340
July1st to 15thDay
7%214425%5%7%9%48%
2209
16th to endDay
5%2135%36%7%9%10%44%
2277
August1st to 15thDay
3214437%7%8%10%45%
2160
16th to endDay
4425%6%46%7%7%8%41%
2292
September1st to 15thDay
13%3145%346%7%8%39%
2145
16th to endDay
10%3144336%5%6%50%
1859
October1st to 15thDay
6%213313347%62%
1799
16th to endDay
421121223473%
1760
November1st to 15thDay
5%222233471%
1641
16th to endDay
6%21112235%71%
1620
December1st to 15thDay
45%1221235%5%65%
1620
16th to endDay
45%12212346%64%
1743
January1st to 15thNight
6%412313335%61%
2148
16th to endNight
6%312213346%63%
2304
February1st to 15thNight
3313312336%67%
2102
16th to endNight
5%31221334467%
1894
March1st to 15thNight
441322335%6%63%
2153
16th to endNight
4312213345%68%
1987
April1st to 15thNight
5%212224346%65%
1798
16th to endNight
212223245%72%
1800
May1st to 15thNight
5%212213346%66%
1799
16th to endNight
42122235%7%7%59%
1729
June1st to 15thNight
11232346%10%63%
1620
16th to endNight
31123245%7%11%56%
1620
July1st to 15thNight
42123245%6%11%54%
1746
16th to endNight
21134245%8%12%52%
1891
August1st to 15thNight
22233235%7%14%52%
1800
16th to endNight
3213436%6%8%13%47%
1910
September1st to 15thNight
8%3134235%8%11%47%
1815
16th to endNight
6%214425%6%7%9%49%
1870
October1st to 15thNight
7%112212347%65%
1829
16th to endNight
3211112335%73%
2112
November1st to 15thNight
3212212225%73%
2205
16th to endNight
5%21231323469%
2340
December1st to 15thNight
5%311212446%65%
2340
16th to endNight
4312223345%65%
2490

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%13223336%60%
1790
16th to endDay
5%312213345%65%
1920
February1st to 15thDay
2313213335%68%
1750
16th to endDay
2412123235%70%
1580
March1st to 15thDay
5%31221445%6%60%
1804
16th to endDay
421121325%6%67%
2233
April1st to 15thDay
3112224347%66%
2150
16th to endDay
311212135%75%
2160
May1st to 15thDay
5%112214346%65%
2151
16th to endDay
5%121235%7%6%63%
2382
June1st to 15thDay
1122346%7%68%
2340
16th to endDay
4212425%5%6%8%55%
2340
July1st to 15thDay
7%214435%47%9%49%
2209
16th to endDay
5%2135%35%7%8%10%45%
2277
August1st to 15thDay
3113437%7%7%11%46%
2160
16th to endDay
43246%46%7%7%8%43%
2292
September1st to 15thDay
14%3145%346%6%8%41%
2145
16th to endDay
10%3144345%5%6%51%
1859
October1st to 15thDay
6%213313347%62%
1799
16th to endDay
5%2111322374%
1760
November1st to 15thDay
5%2111223472%
1641
16th to endDay
6%21112235%71%
1620
December1st to 15thDay
5%5%12213345%65%
1620
16th to endDay
45%12212346%64%
1743
January1st to 15thNight
6%5%13313345%61%
2148
16th to endNight
6%312213346%63%
2304
February1st to 15thNight
3313212336%67%
2102
16th to endNight
5%31221334467%
1894
March1st to 15thNight
5%31221335%6%63%
2153
16th to endNight
4212113345%68%
1987
April1st to 15thNight
5%112223346%65%
1798
16th to endNight
21222324473%
1800
May1st to 15thNight
5%212213345%67%
1799
16th to endNight
42122135%6%7%60%
1729
June1st to 15thNight
1222346%10%63%
1620
16th to endNight
31122245%7%11%57%
1620
July1st to 15thNight
42123235%6%11%55%
1746
16th to endNight
21133345%7%13%52%
1891
August1st to 15thNight
32133235%7%15%52%
1800
16th to endNight
3213426%6%8%13%47%
1910
September1st to 15thNight
8%3143245%7%11%47%
1815
16th to endNight
6%214335%6%7%9%49%
1870
October1st to 15thNight
7%12212346%65%
1829
16th to endNight
321112235%73%
2112
November1st to 15thNight
422212225%73%
2205
16th to endNight
5%21231323369%
2340
December1st to 15thNight
5%311212446%65%
2340
16th to endNight
4312223445%65%
2490

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
26%35%16%30%18%
1791
16th to endDay
20%36%14%30%24%
1920
February1st to 15thDay
19%27%13%24%32%
1751
16th to endDay
17%2411%32%32%
1580
March1st to 15thDay
23%35%13%26%27%
1804
16th to endDay
18%36%10%26%34%
2235
April1st to 15thDay
18%46%8%27%34%
2150
16th to endDay
12%25%9%29%39%
2160
May1st to 15thDay
21%35%10%22%36%
2151
16th to endDay
17%6%9%13%22%30%
2385
June1st to 15thDay
13%5%10%16%25%27%
2340
16th to endDay
25%5%9%19%22%16%
2340
July1st to 15thDay
29%8%13%24%18%6%
2080
16th to endDay
29%10%15%25%15%3
2134
August1st to 15thDay
28%10%15%23%20%2
2147
16th to endDay
36%10%13%20%13%4
2292
September1st to 15thDay
39%9%12%16%15%5%
2145
16th to endDay
32%7%9%17%22%10%
1859
October1st to 15thDay
23%47%19%24%20%
1799
16th to endDay
17%25%12%30%32%
1760
November1st to 15thDay
17%35%19%28%25%
1641
16th to endDay
17%25%13%28%31%
1620
December1st to 15thDay
20%35%18%31%19%
1620
16th to endDay
21%26%20%31%16%
1743
January1st to 15thNight
25%35%12%30%21%
2148
16th to endNight
22%3413%31%25%
2304
February1st to 15thNight
19%25%10%23%36%
2112
16th to endNight
20%25%9%26%35%
1894
March1st to 15thNight
21%35%13%25%30%
2153
16th to endNight
19%26%12%24%35%
1987
April1st to 15thNight
20%47%8%25%34%
1798
16th to endNight
14%28%12%22%39%
1800
May1st to 15thNight
20%37%12%21%35%
1800
16th to endNight
21%6%10%16%18%26%
1731
June1st to 15thNight
16%5%9%21%25%20%
1620
16th to endNight
20%5%14%21%19%19%
1620
July1st to 15thNight
22%5%14%30%21%5%
1646
16th to endNight
21%9%14%30%20%3
1771
August1st to 15thNight
19%7%18%25%26%2
1789
16th to endNight
24%11%14%27%17%4
1910
September1st to 15thNight
28%8%16%24%14%7%
1815
16th to endNight
29%6%12%20%21%9%
1870
October1st to 15thNight
20%49%22%20%22%
1829
16th to endNight
14%25%12%28%35%
2112
November1st to 15thNight
16%2416%32%26%
2205
16th to endNight
20%1410%28%33%
2340
December1st to 15thNight
19%46%18%26%24%
2340
16th to endNight
21%25%16%33%19%
2490

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%36%33%13%
90
16th to endDay
9%20%31%20%14%3
96
February1st to 15thDay
411%17%32%28%5%
90
16th to endDay
7%19%19%33%16%3
81
March1st to 15thDay
36%36%35%15%3
94
16th to endDay
315%40%28%7%3
288
April1st to 15thDay
7%15%42%27%5%1
269
16th to endDay
418%40%29%7%
270
May1st to 15thDay
6%13%40%30%7%
288
16th to endDay
7%331%41%16%
469
June1st to 15thDay
114%47%32%4
495
16th to endDay
319%40%37%8%
495
July1st to 15thDay
5%7%30%40%15%
354
16th to endDay
4428%42%19%
327
August1st to 15thDay
5%323%46%21%
315
16th to endDay
8%7%27%43%13%
332
September1st to 15thDay
9%8%33%36%12%
300
16th to endDay
11%8%34%29%14%
102
October1st to 15thDay
18%115%26%24%13%
90
16th to endDay
6%216%27%30%17%
96
November1st to 15thDay
15%322%28%24%5%
90
16th to endDay
15%13%26%23%17%3
90
December1st to 15thDay
11%10%20%32%24%2
90
16th to endDay
10%8%29%40%11%
96
January1st to 15thNight
8%5%28%37%16%3
720
16th to endNight
7%8%27%37%17%1
768
February1st to 15thNight
6%9%25%35%21%1
704
16th to endNight
7%8%37%35%9%
632
March1st to 15thNight
7%10%26%36%18%1
720
16th to endNight
5%8%31%37%14%1
643
April1st to 15thNight
5%8%36%39%9%
539
16th to endNight
28%35%42%10%
540
May1st to 15thNight
6%5%34%41%11%
540
16th to endNight
5%328%44%17%
563
June1st to 15thNight
26%52%19%
540
16th to endNight
317%52%25%2
540
July1st to 15thNight
410%46%35%2
510
16th to endNight
25%43%43%4
564
August1st to 15thNight
3229%60%3
539
16th to endNight
4428%54%6%
573
September1st to 15thNight
9%333%45%7%
540
16th to endNight
8%7%40%39%3
507
October1st to 15thNight
8%113%43%29%3
509
16th to endNight
4215%36%32%8%
704
November1st to 15thNight
5%222%34%29%5%
805
16th to endNight
6%6%19%38%27%3
900
December1st to 15thNight
7%5%25%40%19%2
900
16th to endNight
6%8%29%40%12%2
954
Page generated at 2017-09-21 06:18:10. Version ac04

Copyright 2017 A. Danko


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