Davis Mountains State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Davis Mountains State Park clear sky chart from 2005-11-06 to 2024-11-04.

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
60%
24478
32%
97088
23%
24283
70%
24283
40%
42238

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 10thNight
48%
754
46%
3657
21%
736
64%
736
41%
1216
January11th to 20thNight
48%
755
47%
3574
21%
740
63%
740
43%
1171
January21st to endNight
47%
828
26%
3875
22%
814
65%
814
30%
1849
February1st to 10thNight
50%
760
39%
2280
21%
760
67%
760
49%
1088
February11th to 20thNight
47%
743
30%
2218
16%
740
60%
740
44%
1139
February21st to endNight
38%
628
35%
1884
16%
628
55%
628
47%
905
March1st to 10thNight
47%
755
38%
3634
16%
744
62%
744
34%
1487
March11th to 20thNight
44%
756
30%
3544
16%
740
56%
740
25%
1833
March21st to endNight
42%
646
27%
3311
23%
626
63%
626
36%
1252
April1st to 10thNight
47%
570
39%
1900
24%
570
67%
570
44%
904
April11th to 20thNight
44%
563
33%
1877
21%
563
62%
563
44%
883
April21st to endNight
49%
570
38%
1900
26%
570
70%
570
54%
808
May1st to 10thNight
52%
567
44%
2926
25%
559
69%
559
43%
957
May11th to 20thNight
58%
555
24%
2999
28%
541
67%
541
33%
1120
May21st to endNight
62%
605
23%
3086
25%
593
72%
593
40%
1025
June1st to 10thNight
74%
570
27%
1710
26%
570
77%
570
50%
848
June11th to 20thNight
73%
570
29%
1710
28%
570
78%
570
48%
869
June21st to endNight
78%
570
27%
1710
28%
570
79%
570
44%
905
July1st to 10thNight
78%
537
22%
2784
21%
535
79%
535
27%
1329
July11th to 20thNight
86%
535
25%
2430
31%
533
86%
533
43%
944
July21st to endNight
84%
604
20%
2811
28%
569
86%
569
28%
1401
August1st to 10thNight
87%
553
34%
2619
33%
545
88%
545
40%
1050
August11th to 20thNight
83%
543
20%
2678
29%
543
84%
543
31%
1142
August21st to endNight
80%
607
17%
3053
23%
605
80%
605
27%
1368
September1st to 10thNight
76%
570
23%
1900
27%
570
77%
570
34%
1060
September11th to 20thNight
77%
570
24%
2011
28%
570
78%
570
32%
1139
September21st to endNight
77%
570
29%
2090
31%
570
79%
570
36%
1070
October1st to 10thNight
75%
550
50%
3072
33%
550
77%
550
40%
998
October11th to 20thNight
67%
677
28%
3254
27%
674
73%
674
40%
1197
October21st to endNight
68%
816
46%
3764
27%
813
75%
813
54%
1189
November1st to 10thNight
66%
794
39%
2302
25%
794
73%
794
57%
1083
November11th to 20thNight
64%
950
36%
2470
20%
950
70%
950
56%
1265
November21st to endNight
54%
950
38%
2470
19%
950
65%
950
49%
1317
December1st to 10thNight
56%
950
37%
2470
20%
950
64%
950
48%
1365
December11th to 20thNight
47%
949
37%
2892
17%
949
60%
949
42%
1508
December21st to endNight
48%
988
28%
4223
20%
979
62%
979
43%
1554

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
331434446%7%61%
104492
Night
331333335%8%64%
103228
TransparencyDay
20%5%9%18%26%23%
104278
Night
18%5%9%19%25%23%
103031
SeeingDay
6%9%24%30%23%8%
14604
Night
5%6%23%39%25%3
24708

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 10thDay
3312223246%73%
3167
11th to 20thDay
2212323245%74%
3170
21st to endDay
342434435%6%63%
3487
February1st to 10thDay
331334446%6%64%
1900
11th to 20thDay
3414233446%64%
1849
21st to endDay
231322335%8%68%
1570
March1st to 10thDay
2426%44446%8%56%
3130
11th to 20thDay
7%6%1433435%7%57%
3381
21st to endDay
131444446%7%62%
4130
April1st to 10thDay
231333436%7%66%
2280
11th to 20thDay
241433445%6%65%
2251
21st to endDay
2313322246%71%
2280
May1st to 10thDay
2212222247%75%
3800
11th to 20thDay
331323435%7%67%
3765
21st to endDay
211222335%6%74%
4444
June1st to 10thDay
21133445%8%8%61%
2470
11th to 20thDay
221445%5%5%7%8%58%
2470
21st to endDay
5%5%15%445%5%8%9%50%
2470
July1st to 10thDay
5%3145%5%8%6%8%10%44%
3815
11th to 20thDay
321345%6%5%8%9%54%
3800
21st to endDay
5%425%5%6%7%6%8%10%43%
4118
August1st to 10thDay
2213446%5%8%11%54%
3784
11th to 20thDay
4325%46%5%5%7%9%50%
3726
21st to endDay
4425%45%6%47%9%50%
4180
September1st to 10thDay
10%5%26%5%6%6%5%7%8%42%
2280
11th to 20thDay
10%5%27%5%5%6%5%7%7%40%
2166
21st to endDay
8%5%25%44445%7%52%
2090
October1st to 10thDay
321322324475%
3480
11th to 20thDay
4214223245%71%
3247
21st to endDay
2212212135%80%
3438
November1st to 10thDay
4412222245%71%
1828
11th to 20thDay
2414333445%68%
1710
21st to endDay
5%414322245%65%
1710
December1st to 10thDay
6%42333425%6%61%
1710
11th to 20thDay
2314345%46%8%61%
2161
21st to endDay
231222235%6%71%
3235
January1st to 10thNight
2213233245%71%
3788
11th to 20thNight
331322225%7%71%
3800
21st to endNight
4425%44445%8%57%
4180
February1st to 10thNight
341332335%7%65%
2280
11th to 20thNight
431434435%7%61%
2218
21st to endNight
331323345%7%65%
1884
March1st to 10thNight
3425%44436%8%59%
3734
11th to 20thNight
6%11%3433335%6%53%
3593
21st to endNight
2313335%36%7%64%
3511
April1st to 10thNight
4314334346%64%
1900
11th to 20thNight
431443335%7%63%
1877
21st to endNight
2312233245%73%
1900
May1st to 10thNight
2313222325%75%
3170
11th to 20thNight
5%41323335%6%66%
3140
21st to endNight
221233336%7%68%
3138
June1st to 10thNight
22144345%8%10%58%
1710
11th to 20thNight
32144446%8%8%55%
1710
21st to endNight
5%31344446%10%55%
1710
July1st to 10thNight
3325%44448%12%51%
3134
11th to 20thNight
211222336%11%67%
3170
21st to endNight
4414345%5%7%12%52%
3445
August1st to 10thNight
211233448%13%58%
3155
11th to 20thNight
221344449%12%56%
3113
21st to endNight
331433447%11%57%
3487
September1st to 10thNight
7%5%15%345%45%9%51%
1900
11th to 20thNight
7%6%15%45%5%47%11%47%
2011
21st to endNight
5%424335%46%8%55%
2090
October1st to 10thNight
2213322345%74%
3480
11th to 20thNight
4213223345%70%
3673
21st to endNight
221212212482%
4120
November1st to 10thNight
5%413222235%72%
2302
11th to 20thNight
25%13223345%68%
2470
21st to endNight
431433325%6%65%
2470
December1st to 10thNight
6%313334347%61%
2470
11th to 20thNight
25%25%43425%8%61%
3036
21st to endNight
2312223336%73%
4459

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 10thDay
14%2413%27%40%
3168
11th to 20thDay
13%35%14%42%24%
3170
21st to endDay
21%47%18%33%16%
3487
February1st to 10thDay
18%47%14%25%31%
1900
11th to 20thDay
21%46%14%26%29%
1859
21st to endDay
15%35%14%30%33%
1570
March1st to 10thDay
22%46%11%25%32%
3130
11th to 20thDay
24%5%7%16%25%24%
3381
21st to endDay
18%47%9%30%32%
4130
April1st to 10thDay
17%36%13%28%33%
2280
11th to 20thDay
17%6%6%10%28%33%
2254
21st to endDay
15%35%12%34%32%
2280
May1st to 10thDay
11%35%11%22%48%
3800
11th to 20thDay
15%5%8%12%24%37%
3768
21st to endDay
10%47%15%19%45%
4444
June1st to 10thDay
16%7%13%21%26%17%
2470
11th to 20thDay
18%6%9%17%27%23%
2470
21st to endDay
25%7%12%22%20%13%
2470
July1st to 10thDay
28%9%17%29%15%2
3756
11th to 20thDay
20%8%15%32%21%3
3737
21st to endDay
30%9%14%26%18%4
3988
August1st to 10thDay
20%8%13%31%26%3
3772
11th to 20thDay
27%8%14%25%22%4
3762
21st to endDay
28%8%15%28%18%3
4179
September1st to 10thDay
36%9%13%17%15%10%
2280
11th to 20thDay
35%9%13%17%18%8%
2166
21st to endDay
29%6%9%20%23%13%
2090
October1st to 10thDay
12%5%6%13%25%39%
3480
11th to 20thDay
15%38%21%21%32%
3247
21st to endDay
10%2214%46%27%
3438
November1st to 10thDay
15%38%18%29%26%
1828
11th to 20thDay
18%46%21%28%22%
1710
21st to endDay
21%36%18%29%22%
1710
December1st to 10thDay
24%36%20%29%18%
1710
11th to 20thDay
20%47%18%30%21%
2159
21st to endDay
14%3415%32%32%
3235
January1st to 10thNight
15%3410%34%35%
3788
11th to 20thNight
14%25%15%34%30%
3800
21st to endNight
25%5%6%16%34%14%
4180
February1st to 10thNight
18%46%14%25%33%
2280
11th to 20thNight
23%48%12%24%29%
2218
21st to endNight
19%35%9%28%37%
1884
March1st to 10thNight
21%46%11%23%36%
3734
11th to 20thNight
24%13%6%11%23%23%
3593
21st to endNight
18%36%10%32%31%
3511
April1st to 10thNight
21%45%12%27%31%
1900
11th to 20thNight
20%5%8%12%24%32%
1877
21st to endNight
13%47%15%27%34%
1900
May1st to 10thNight
11%5%49%22%49%
3170
11th to 20thNight
18%6%8%14%19%35%
3141
21st to endNight
14%5%9%15%18%39%
3139
June1st to 10thNight
17%7%13%27%23%13%
1710
11th to 20thNight
20%6%11%20%25%18%
1710
21st to endNight
22%7%14%23%21%12%
1710
July1st to 10thNight
24%8%18%37%12%2
3084
11th to 20thNight
12%6%16%42%22%3
3110
21st to endNight
23%7%16%35%17%2
3336
August1st to 10thNight
14%6%15%35%27%3
3144
11th to 20thNight
19%6%21%33%19%2
3143
21st to endNight
21%7%20%32%17%3
3487
September1st to 10thNight
28%9%16%21%16%10%
1900
11th to 20thNight
29%10%17%20%16%8%
2011
21st to endNight
25%7%13%21%20%13%
2090
October1st to 10thNight
13%48%12%22%40%
3480
11th to 20thNight
15%411%18%19%33%
3673
21st to endNight
10%2313%42%29%
4120
November1st to 10thNight
16%36%15%34%25%
2302
11th to 20thNight
17%46%20%28%25%
2470
21st to endNight
21%46%16%31%23%
2470
December1st to 10thNight
23%47%20%26%20%
2470
11th to 20thNight
23%45%18%27%24%
3037
21st to endNight
15%3416%36%26%
4459

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 10thDay
9%20%33%28%10%1
270
11th to 20thDay
7%14%36%29%13%1
270
21st to endDay
5%21%34%29%8%3
297
February1st to 10thDay
9%14%33%27%17%1
270
11th to 20thDay
10%17%41%21%11%
270
21st to endDay
9%19%44%21%6%1
225
March1st to 10thDay
7%14%46%22%9%1
270
11th to 20thDay
10%18%41%21%7%3
390
21st to endDay
7%21%45%21%6%
506
April1st to 10thDay
6%17%44%23%8%1
460
11th to 20thDay
6%19%46%23%6%1
452
21st to endDay
5%17%43%29%6%1
460
May1st to 10thDay
411%44%28%11%2
463
11th to 20thDay
5%8%34%39%11%3
488
21st to endDay
4434%40%17%2
702
June1st to 10thDay
3216%44%31%5%
680
11th to 20thDay
2212%44%35%5%
680
21st to endDay
6%27%33%41%12%
680
July1st to 10thDay
5%2427%40%21%
501
11th to 20thDay
41228%43%21%
484
21st to endDay
31432%42%19%
531
August1st to 10thDay
31320%46%26%
487
11th to 20thDay
5%35%25%40%21%
477
21st to endDay
8%2322%42%23%
539
September1st to 10thDay
9%35%32%34%16%
490
11th to 20thDay
9%17%31%34%17%
376
21st to endDay
9%110%34%31%16%
300
October1st to 10thDay
9%214%32%33%11%
300
11th to 20thDay
6%5%24%36%23%6%
300
21st to endDay
7%10%26%28%18%11%
330
November1st to 10thDay
8%8%27%32%20%6%
279
11th to 20thDay
6%11%26%32%17%9%
270
21st to endDay
9%19%29%26%12%4
270
December1st to 10thDay
10%10%28%34%15%2
270
11th to 20thDay
6%17%36%29%11%1
270
21st to endDay
5%19%36%29%10%1
297
January1st to 10thNight
6%8%32%39%13%2
760
11th to 20thNight
7%8%33%36%15%1
760
21st to endNight
5%9%33%38%14%1
836
February1st to 10thNight
5%11%31%35%17%1
760
11th to 20thNight
7%6%36%39%12%1
744
21st to endNight
5%11%42%35%6%
628
March1st to 10thNight
5%10%34%38%12%1
760
11th to 20thNight
7%10%32%34%15%1
760
21st to endNight
49%42%37%8%1
648
April1st to 10thNight
5%10%34%39%12%1
570
11th to 20thNight
6%9%37%40%8%
563
21st to endNight
28%38%42%9%1
570
May1st to 10thNight
46%34%44%13%1
570
11th to 20thNight
7%5%25%48%14%1
561
21st to endNight
35%25%49%18%
617
June1st to 10thNight
2116%54%26%1
570
11th to 20thNight
4113%54%26%2
570
21st to endNight
5%27%47%38%1
570
July1st to 10thNight
425%35%52%3
555
11th to 20thNight
3339%50%5%
552
21st to endNight
21236%55%4
624
August1st to 10thNight
21124%65%7%
567
11th to 20thNight
41225%60%9%
564
21st to endNight
5%1127%60%5%
627
September1st to 10thNight
8%3326%54%6%
570
11th to 20thNight
9%1436%46%4
570
21st to endNight
7%26%38%42%5%
570
October1st to 10thNight
5%210%45%35%4
570
11th to 20thNight
9%316%44%26%3
694
21st to endNight
6%419%39%26%7%
836
November1st to 10thNight
7%220%40%27%5%
794
11th to 20thNight
5%5%22%43%24%2
950
21st to endNight
6%9%25%39%18%4
950
December1st to 10thNight
8%5%26%41%17%3
950
11th to 20thNight
5%8%34%39%13%1
950
21st to endNight
5%12%31%38%12%2
998
Page generated at 2024-11-01 21:47:32. Version ac07

Copyright © 2024 Attilla Danko.


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