San Angelo State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the San Angelo State Park clear sky chart from 2005-11-06 to 2024-03-08.

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
48%
24085
31%
79428
19%
23995
61%
23995
41%
39642

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
38%
940
38%
3952
13%
926
52%
926
34%
1788
January11th to 20thNight
39%
887
39%
3789
14%
873
53%
873
37%
1488
January21st to endNight
36%
824
25%
4075
16%
814
56%
814
26%
1945
February1st to 10thNight
33%
760
34%
2280
14%
760
51%
760
38%
1226
February11th to 20thNight
29%
743
26%
2218
10%
740
43%
740
34%
1241
February21st to endNight
25%
628
32%
1884
8%
628
45%
628
36%
998
March1st to 10thNight
30%
750
30%
2250
10%
750
46%
750
35%
1253
March11th to 20thNight
31%
544
28%
1984
14%
544
49%
544
31%
1022
March21st to endNight
27%
594
31%
2178
14%
594
51%
594
38%
1006
April1st to 10thNight
27%
540
33%
1855
13%
540
53%
540
38%
909
April11th to 20thNight
28%
533
30%
1777
12%
533
51%
533
37%
925
April21st to endNight
30%
540
33%
1800
14%
540
58%
540
44%
841
May1st to 10thNight
35%
540
30%
1625
16%
540
53%
540
41%
845
May11th to 20thNight
41%
531
24%
1593
18%
531
53%
531
40%
879
May21st to endNight
45%
582
26%
1745
16%
582
61%
582
43%
928
June1st to 10thNight
61%
540
24%
1620
20%
540
71%
540
55%
765
June11th to 20thNight
57%
540
29%
1620
23%
540
68%
540
59%
737
June21st to endNight
67%
540
28%
1620
28%
540
72%
540
53%
783
July1st to 10thNight
75%
525
21%
1575
21%
525
78%
525
44%
840
July11th to 20thNight
81%
522
35%
1566
36%
522
86%
522
65%
683
July21st to endNight
85%
591
36%
1700
41%
558
89%
558
64%
740
August1st to 10thNight
83%
537
32%
1779
38%
534
87%
534
60%
744
August11th to 20thNight
76%
534
30%
1778
35%
534
79%
534
40%
923
August21st to endNight
82%
594
26%
1980
28%
594
85%
594
45%
960
September1st to 10thNight
74%
540
27%
1912
30%
540
77%
540
37%
996
September11th to 20thNight
69%
540
26%
1980
28%
540
73%
540
34%
1042
September21st to endNight
67%
540
32%
1980
29%
540
74%
540
41%
949
October1st to 10thNight
65%
540
37%
1980
33%
540
73%
540
48%
879
October11th to 20thNight
53%
540
39%
1980
26%
540
69%
540
42%
919
October21st to endNight
52%
763
37%
2347
20%
763
63%
763
44%
1183
November1st to 10thNight
53%
925
33%
2405
16%
925
61%
925
50%
1311
November11th to 20thNight
50%
950
31%
2470
14%
950
58%
950
49%
1330
November21st to endNight
40%
950
33%
2470
13%
950
50%
950
39%
1479
December1st to 10thNight
43%
950
36%
2470
15%
950
56%
950
45%
1379
December11th to 20thNight
39%
950
33%
2885
14%
949
52%
949
35%
1628
December21st to endNight
39%
1038
22%
4306
14%
1026
52%
1026
32%
2078

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
8%423424447%59%
79109
Night
8%42332345%7%61%
80511
TransparencyDay
27%49%22%25%14%
78836
Night
24%39%22%26%16%
80304
SeeingDay
10%7%24%32%22%6%
13980
Night
9%7%31%38%14%1
24123

By Month

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 10thDay
9%5%2432323463%
2847
11th to 20thDay
6%413322246%67%
2960
21st to endDay
10%6%2432345%6%56%
3487
February1st to 10thDay
9%424424436%59%
1900
11th to 20thDay
10%6%24324445%56%
1849
21st to endDay
9%6%23313346%60%
1570
March1st to 10thDay
10%6%24434447%51%
1870
11th to 20thDay
12%7%23324345%56%
1975
21st to endDay
8%323322347%63%
2178
April1st to 10thDay
8%324324447%60%
2099
11th to 20thDay
10%424423436%57%
2134
21st to endDay
10%424322346%62%
2160
May1st to 10thDay
9%42443445%6%56%
2335
11th to 20thDay
11%6%3442435%7%52%
2302
21st to endDay
9%435%43446%8%50%
2531
June1st to 10thDay
421232345%9%64%
2340
11th to 20thDay
421232445%8%63%
2340
21st to endDay
6%313325%46%9%56%
2340
July1st to 10thDay
7%3246%46%7%8%9%45%
2340
11th to 20thDay
321333445%7%66%
2340
21st to endDay
32123345%6%10%61%
2512
August1st to 10thDay
211222435%7%71%
2149
11th to 20thDay
6%424445%5%6%10%52%
2123
21st to endDay
43245%45%6%7%9%51%
2376
September1st to 10thDay
9%4235%35%6%5%7%52%
2048
11th to 20thDay
10%425%6%245%5%8%48%
1980
21st to endDay
10%313434446%57%
1980
October1st to 10thDay
6%31342345%6%63%
1980
11th to 20thDay
9%413323235%66%
1980
21st to endDay
11%32322223466%
1985
November1st to 10thDay
10%423223336%63%
1673
11th to 20thDay
6%423324346%64%
1710
21st to endDay
10%424433435%57%
1710
December1st to 10thDay
12%5%14424435%57%
1710
11th to 20thDay
8%5%24424446%56%
2161
21st to endDay
10%5%2321222466%
3135
January1st to 10thNight
7%5%24322335%64%
4108
11th to 20thNight
7%412212235%69%
4024
21st to endNight
11%5%24323347%57%
4180
February1st to 10thNight
9%5%23423346%60%
2280
11th to 20thNight
12%424433336%56%
2218
21st to endNight
9%5%1332335%6%60%
1884
March1st to 10thNight
10%5%2443445%5%55%
2250
11th to 20thNight
11%424324336%58%
1984
21st to endNight
6%413323448%62%
2178
April1st to 10thNight
6%413423448%61%
1855
11th to 20thNight
10%41342435%5%58%
1777
21st to endNight
8%31322334467%
1800
May1st to 10thNight
6%42333446%6%60%
1625
11th to 20thNight
9%32433447%9%53%
1593
21st to endNight
7%4233235%7%10%55%
1745
June1st to 10thNight
221232347%10%64%
1620
11th to 20thNight
311232447%9%65%
1620
21st to endNight
33223235%47%65%
1620
July1st to 10thNight
5%323435%6%7%12%52%
1620
11th to 20thNight
221221335%8%71%
1620
21st to endNight
211232447%11%65%
1800
August1st to 10thNight
221222345%7%70%
1790
11th to 20thNight
43245%35%5%7%10%53%
1778
21st to endNight
32124347%7%11%57%
1980
September1st to 10thNight
6%41343446%7%55%
1912
11th to 20thNight
9%4245%3446%8%52%
1980
21st to endNight
8%423323348%59%
1980
October1st to 10thNight
5%213323447%65%
1980
11th to 20thNight
11%31232233466%
1980
21st to endNight
9%42322333366%
2347
November1st to 10thNight
9%413323345%65%
2405
11th to 20thNight
5%31332445%5%65%
2470
21st to endNight
12%42432345%5%56%
2470
December1st to 10thNight
10%423323347%60%
2470
11th to 20thNight
9%424424447%55%
3036
21st to endNight
10%5%23323345%61%
4532

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
27%2416%29%22%
2848
11th to 20thDay
21%28%16%34%18%
2960
21st to endDay
30%36%19%30%11%
3487
February1st to 10thDay
30%25%17%25%21%
1900
11th to 20thDay
32%25%21%22%18%
1859
21st to endDay
28%3313%31%22%
1570
March1st to 10thDay
34%36%16%26%15%
1870
11th to 20thDay
32%35%18%22%19%
1975
21st to endDay
24%28%23%24%19%
2178
April1st to 10thDay
26%38%19%24%21%
2099
11th to 20thDay
31%36%15%25%20%
2134
21st to endDay
26%26%20%27%18%
2160
May1st to 10thDay
30%39%18%23%17%
2335
11th to 20thDay
34%39%23%21%10%
2306
21st to endDay
32%5%12%24%21%7%
2531
June1st to 10thDay
19%5%12%31%26%7%
2340
11th to 20thDay
19%5%11%29%26%11%
2340
21st to endDay
24%5%12%26%24%9%
2340
July1st to 10thDay
33%7%18%27%12%3
2276
11th to 20thDay
17%5%13%34%24%7%
2271
21st to endDay
16%5%18%40%19%1
2372
August1st to 10thDay
14%412%35%30%5%
2136
11th to 20thDay
28%6%15%30%16%4
2123
21st to endDay
28%6%15%26%20%5%
2376
September1st to 10thDay
31%6%10%23%21%9%
2048
11th to 20thDay
34%5%11%21%22%7%
1980
21st to endDay
27%48%23%25%14%
1980
October1st to 10thDay
22%410%25%26%12%
1980
11th to 20thDay
23%37%18%28%22%
1980
21st to endDay
26%2417%32%20%
1985
November1st to 10thDay
25%26%26%25%16%
1673
11th to 20thDay
23%29%21%27%18%
1710
21st to endDay
31%25%18%28%16%
1710
December1st to 10thDay
31%26%20%28%13%
1710
11th to 20thDay
30%29%17%24%18%
2159
21st to endDay
26%2220%31%20%
3135
January1st to 10thNight
25%3317%33%20%
4108
11th to 20thNight
20%25%21%29%23%
4024
21st to endNight
30%35%19%28%15%
4180
February1st to 10thNight
28%27%16%24%22%
2280
11th to 20thNight
32%25%16%23%21%
2218
21st to endNight
28%25%14%27%24%
1884
March1st to 10thNight
30%36%18%25%18%
2250
11th to 20thNight
30%38%17%21%21%
1984
21st to endNight
22%411%21%22%19%
2178
April1st to 10thNight
23%48%23%20%22%
1855
11th to 20thNight
27%48%19%20%21%
1777
21st to endNight
21%39%24%29%15%
1800
May1st to 10thNight
24%5%10%21%24%16%
1625
11th to 20thNight
27%5%15%22%22%9%
1594
21st to endNight
23%6%17%27%21%7%
1746
June1st to 10thNight
17%418%32%24%5%
1620
11th to 20thNight
15%414%31%27%10%
1620
21st to endNight
17%5%13%27%28%10%
1620
July1st to 10thNight
24%5%19%32%16%3
1575
11th to 20thNight
12%314%32%29%11%
1566
21st to endNight
12%417%40%25%2
1700
August1st to 10thNight
13%411%33%32%6%
1779
11th to 20thNight
26%5%14%30%21%5%
1778
21st to endNight
20%6%18%27%21%7%
1980
September1st to 10thNight
26%7%11%24%22%10%
1912
11th to 20thNight
29%5%14%22%22%7%
1980
21st to endNight
25%29%25%22%16%
1980
October1st to 10thNight
20%312%25%24%16%
1980
11th to 20thNight
24%27%18%27%22%
1980
21st to endNight
24%2418%29%23%
2347
November1st to 10thNight
24%27%22%25%20%
2405
11th to 20thNight
22%37%21%27%21%
2470
21st to endNight
31%35%16%27%18%
2470
December1st to 10thNight
27%28%22%26%16%
2470
11th to 20thNight
31%26%18%25%18%
3037
21st to endNight
27%3317%30%19%
4532

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
13%16%33%31%6%1
270
11th to 20thDay
13%17%30%28%10%2
270
21st to endDay
11%12%43%23%9%2
297
February1st to 10thDay
17%12%41%22%8%
270
11th to 20thDay
17%11%42%24%41
270
21st to endDay
16%14%46%20%3
225
March1st to 10thDay
16%10%41%26%7%
261
11th to 20thDay
22%12%35%18%11%2
240
21st to endDay
13%17%39%23%6%1
264
April1st to 10thDay
12%14%44%24%6%1
359
11th to 20thDay
12%18%42%23%4
412
21st to endDay
11%17%40%25%6%1
420
May1st to 10thDay
11%10%38%32%7%1
598
11th to 20thDay
15%6%29%34%14%3
625
21st to endDay
10%5%31%38%14%1
679
June1st to 10thDay
5%217%48%25%4
630
11th to 20thDay
3122%46%23%4
630
21st to endDay
3213%39%35%7%
630
July1st to 10thDay
7%37%34%37%12%
621
11th to 20thDay
215%38%44%10%
618
21st to endDay
2334%46%15%
650
August1st to 10thDay
21334%44%16%
447
11th to 20thDay
8%1433%40%14%
437
21st to endDay
5%16%30%41%17%
495
September1st to 10thDay
7%2431%38%18%
338
11th to 20thDay
5%26%29%38%20%
270
21st to endDay
14%27%29%33%15%
270
October1st to 10thDay
4216%37%33%7%
270
11th to 20thDay
11%427%33%21%3
270
21st to endDay
18%7%27%26%18%4
297
November1st to 10thDay
16%430%31%18%2
270
11th to 20thDay
13%10%27%31%13%6%
270
21st to endDay
17%16%30%21%12%3
270
December1st to 10thDay
18%6%27%37%10%3
270
11th to 20thDay
9%14%35%30%11%1
270
21st to endDay
18%11%38%23%11%
297
January1st to 10thNight
11%7%39%34%9%
950
11th to 20thNight
12%9%34%35%9%
893
21st to endNight
11%10%39%34%6%
836
February1st to 10thNight
14%9%40%31%6%
760
11th to 20thNight
14%12%42%29%3
744
21st to endNight
14%15%44%25%2
628
March1st to 10thNight
13%11%42%30%5%
750
11th to 20thNight
13%12%42%29%5%
544
21st to endNight
7%13%50%27%3
594
April1st to 10thNight
6%12%51%27%4
540
11th to 20thNight
10%8%51%27%3
533
21st to endNight
7%10%50%27%5%
540
May1st to 10thNight
6%9%46%34%4
540
11th to 20thNight
11%5%38%35%10%
531
21st to endNight
7%340%39%11%1
584
June1st to 10thNight
3228%51%15%1
540
11th to 20thNight
2235%51%10%
540
21st to endNight
3220%52%21%1
540
July1st to 10thNight
7%19%48%33%2
525
11th to 20thNight
39%56%30%1
522
21st to endNight
26%61%31%1
591
August1st to 10thNight
119%53%36%1
537
11th to 20thNight
5%17%45%37%5%
534
21st to endNight
417%41%43%4
594
September1st to 10thNight
6%19%44%37%2
540
11th to 20thNight
10%17%44%35%2
540
21st to endNight
10%115%46%28%1
540
October1st to 10thNight
6%123%47%23%
540
11th to 20thNight
12%6%26%41%14%1
540
21st to endNight
11%6%27%40%15%1
763
November1st to 10thNight
12%427%40%16%1
925
11th to 20thNight
7%8%30%41%13%1
950
21st to endNight
14%8%34%31%11%1
950
December1st to 10thNight
13%6%35%36%10%
950
11th to 20thNight
13%11%32%37%7%
950
21st to endNight
12%9%36%37%6%
1045
Page generated at 2024-03-05 06:24:01. Version ac07

Copyright © 2024 Attilla Danko.


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