Mission Tejas State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mission Tejas State Park clear sky chart from 2005-11-06 to 2024-01-12.

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
46%
23850
25%
74194
17%
23790
55%
23790
31%
43241

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
30%
950
28%
2458
9%
946
42%
946
30%
1563
January11th to 20thNight
29%
910
25%
2366
9%
910
39%
910
27%
1539
January21st to endNight
28%
990
27%
2574
9%
990
39%
990
29%
1679
February1st to 10thNight
25%
894
23%
2334
7%
894
34%
894
26%
1550
February11th to 20thNight
23%
704
20%
2098
7%
700
33%
700
22%
1358
February21st to endNight
20%
444
26%
1628
11%
444
38%
444
19%
1004
March1st to 10thNight
27%
540
24%
1980
12%
540
41%
540
21%
1212
March11th to 20thNight
27%
540
22%
1980
13%
540
39%
540
20%
1204
March21st to endNight
29%
594
23%
2178
13%
594
43%
594
26%
1249
April1st to 10thNight
29%
540
24%
1980
14%
540
44%
540
23%
1145
April11th to 20thNight
31%
533
24%
1783
13%
533
45%
533
26%
1040
April21st to endNight
32%
540
26%
1800
15%
540
49%
540
30%
1014
May1st to 10thNight
34%
540
22%
1701
16%
540
45%
540
31%
1001
May11th to 20thNight
44%
531
23%
1594
20%
531
53%
531
34%
944
May21st to endNight
52%
584
24%
1745
19%
582
63%
582
35%
1019
June1st to 10thNight
69%
540
20%
1620
21%
540
72%
540
40%
886
June11th to 20thNight
70%
540
23%
1620
23%
540
75%
540
51%
791
June21st to endNight
70%
540
23%
1620
26%
540
73%
540
38%
909
July1st to 10thNight
72%
525
20%
1575
22%
525
75%
525
37%
920
July11th to 20thNight
80%
522
23%
1566
26%
522
84%
522
51%
781
July21st to endNight
80%
591
20%
1673
22%
558
83%
558
43%
897
August1st to 10thNight
84%
537
28%
1601
32%
534
86%
534
58%
740
August11th to 20thNight
77%
534
25%
1659
28%
534
78%
534
37%
922
August21st to endNight
76%
594
20%
1980
22%
594
78%
594
32%
1150
September1st to 10thNight
73%
540
22%
1951
27%
540
75%
540
34%
1049
September11th to 20thNight
67%
540
22%
1980
25%
540
69%
540
29%
1138
September21st to endNight
71%
540
31%
1980
33%
540
73%
540
37%
989
October1st to 10thNight
70%
649
33%
2089
28%
649
74%
649
44%
1036
October11th to 20thNight
54%
720
34%
2160
20%
720
64%
720
39%
1198
October21st to endNight
47%
792
34%
2376
20%
792
57%
792
37%
1320
November1st to 10thNight
52%
740
30%
2220
21%
740
59%
740
37%
1253
November11th to 20thNight
45%
760
29%
2280
19%
760
53%
760
34%
1316
November21st to endNight
37%
874
27%
2394
15%
874
46%
874
29%
1531
December1st to 10thNight
35%
950
28%
2470
12%
950
44%
950
31%
1588
December11th to 20thNight
30%
949
26%
2865
11%
948
38%
948
23%
1856
December21st to endNight
31%
1039
16%
4316
11%
1026
39%
1026
19%
2450

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
12%6%35%5%35%5%5%7%44%
74961
Night
12%5%2442445%7%51%
74788
TransparencyDay
39%5%11%20%19%7%
74686
Night
34%411%20%21%10%
74583
SeeingDay
14%8%23%27%22%6%
13890
Night
15%8%25%32%17%2
23857

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
16%8%34423345%48%
1707
11th to 20thDay
19%7%25%323345%46%
1634
21st to endDay
19%7%34422336%48%
1782
February1st to 10thDay
22%8%36%5%33325%41%
1642
11th to 20thDay
23%7%35%5%23335%40%
1749
21st to endDay
22%6%35%42434442%
1628
March1st to 10thDay
20%7%36%43445%6%39%
1980
11th to 20thDay
19%7%26%5%3445%5%40%
1980
21st to endDay
16%7%35%5%34346%43%
2178
April1st to 10thDay
14%7%36%5%4445%7%42%
1980
11th to 20thDay
15%6%35%435%5%6%8%39%
2124
21st to endDay
12%5%345%35%5%5%7%46%
2160
May1st to 10thDay
13%6%36%6%35%5%6%8%40%
2255
11th to 20thDay
12%6%26%6%45%5%5%7%43%
2302
21st to endDay
9%6%36%6%5%6%6%7%10%36%
2531
June1st to 10thDay
6%435%6%46%7%8%10%40%
2340
11th to 20thDay
5%325%6%5%6%7%7%11%43%
2340
21st to endDay
7%5%26%6%47%7%7%11%39%
2340
July1st to 10thDay
9%5%46%8%47%7%7%11%33%
2340
11th to 20thDay
5%3245%46%7%8%11%44%
2340
21st to endDay
5%326%5%46%7%7%11%42%
2546
August1st to 10thDay
42234345%7%11%55%
2328
11th to 20thDay
6%4247%46%6%7%10%44%
2239
21st to endDay
7%426%7%5%6%7%7%10%40%
2376
September1st to 10thDay
8%5%35%6%46%5%6%7%46%
2004
11th to 20thDay
13%5%25%6%36%5%6%7%42%
1980
21st to endDay
7%324435%45%8%53%
1980
October1st to 10thDay
7%323434446%60%
1850
11th to 20thDay
13%5%23233445%55%
1800
21st to endDay
15%5%23323335%56%
1980
November1st to 10thDay
13%6%2442445%7%49%
1858
11th to 20thDay
13%5%24424446%52%
1900
21st to endDay
18%6%36%43344444%
1782
December1st to 10thDay
17%6%25%424446%45%
1710
11th to 20thDay
18%8%345%34345%43%
2161
21st to endDay
16%9%37%5%24435%42%
3135
January1st to 10thNight
16%7%24423447%49%
2458
11th to 20thNight
19%7%24323335%48%
2366
21st to endNight
17%8%35%423345%48%
2574
February1st to 10thNight
18%8%34324345%46%
2334
11th to 20thNight
20%8%35%32334445%
2098
21st to endNight
20%6%25%424445%44%
1628
March1st to 10thNight
17%7%35%5%33346%43%
1980
11th to 20thNight
16%6%36%4335%5%6%44%
1980
21st to endNight
15%5%35%423346%50%
2178
April1st to 10thNight
11%426%5%345%5%6%49%
1980
11th to 20thNight
13%5%25%425%45%7%47%
1783
21st to endNight
12%424424346%53%
1800
May1st to 10thNight
9%6%345%345%7%9%47%
1701
11th to 20thNight
12%425%42445%8%51%
1593
21st to endNight
9%424435%46%10%49%
1745
June1st to 10thNight
5%315%5%235%5%11%54%
1620
11th to 20thNight
322232346%9%64%
1620
21st to endNight
7%413435%5%7%11%51%
1620
July1st to 10thNight
5%3345%36%5%7%11%48%
1620
11th to 20thNight
32123244411%63%
1620
21st to endNight
4313335%6%8%14%51%
1772
August1st to 10thNight
321222246%11%65%
1611
11th to 20thNight
6%3245%25%5%7%12%50%
1659
21st to endNight
6%3235%35%7%9%12%45%
1980
September1st to 10thNight
7%4245%3445%9%52%
1951
11th to 20thNight
9%5%26%5%35%46%7%49%
1980
21st to endNight
7%42442345%7%59%
1980
October1st to 10thNight
5%31432445%7%63%
2089
11th to 20thNight
13%323424345%59%
2160
21st to endNight
16%41332233460%
2376
November1st to 10thNight
12%414323346%57%
2220
11th to 20thNight
11%6%24423446%54%
2280
21st to endNight
16%6%2442445%5%47%
2394
December1st to 10thNight
16%6%243245%46%47%
2470
11th to 20thNight
16%8%26%5%23336%46%
3036
21st to endNight
16%7%25%423335%50%
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
40%36%18%24%8%
1708
11th to 20thDay
43%25%18%23%8%
1634
21st to endDay
41%2417%24%12%
1782
February1st to 10thDay
50%2414%19%10%
1642
11th to 20thDay
50%26%15%19%8%
1759
21st to endDay
47%27%13%18%13%
1628
March1st to 10thDay
48%37%14%19%8%
1980
11th to 20thDay
46%37%15%21%7%
1980
21st to endDay
44%48%16%23%6%
2178
April1st to 10thDay
43%49%20%16%7%
1980
11th to 20thDay
44%410%15%18%9%
2124
21st to endDay
38%5%9%20%24%5%
2160
May1st to 10thDay
42%5%10%20%16%6%
2255
11th to 20thDay
42%412%23%17%2
2306
21st to endDay
43%6%14%20%16%1
2531
June1st to 10thDay
38%6%15%25%14%2
2340
11th to 20thDay
34%6%14%28%16%3
2340
21st to endDay
38%9%14%24%14%2
2340
July1st to 10thDay
42%10%18%21%8%
2276
11th to 20thDay
32%6%19%27%14%1
2271
21st to endDay
33%7%22%27%10%
2405
August1st to 10thDay
25%6%18%34%15%1
2314
11th to 20thDay
34%7%18%26%12%2
2239
21st to endDay
39%8%16%23%11%3
2376
September1st to 10thDay
36%6%13%20%17%8%
2004
11th to 20thDay
40%6%13%16%18%7%
1980
21st to endDay
31%5%9%22%21%13%
1980
October1st to 10thDay
26%410%22%23%15%
1850
11th to 20thDay
32%46%17%25%16%
1800
21st to endDay
34%35%15%29%15%
1980
November1st to 10thDay
36%48%20%23%10%
1858
11th to 20thDay
36%36%20%24%11%
1900
21st to endDay
45%36%18%20%9%
1782
December1st to 10thDay
42%39%18%19%9%
1710
11th to 20thDay
45%26%16%22%9%
2159
21st to endDay
47%25%14%24%9%
3135
January1st to 10thNight
38%35%19%23%12%
2458
11th to 20thNight
41%27%17%22%10%
2366
21st to endNight
41%2415%23%14%
2574
February1st to 10thNight
43%35%16%18%15%
2334
11th to 20thNight
45%36%16%20%11%
2098
21st to endNight
44%38%12%16%16%
1628
March1st to 10thNight
44%37%15%20%11%
1980
11th to 20thNight
41%5%10%13%23%8%
1980
21st to endNight
37%411%16%22%10%
2178
April1st to 10thNight
38%49%21%17%11%
1980
11th to 20thNight
37%411%20%17%12%
1783
21st to endNight
34%410%19%25%7%
1800
May1st to 10thNight
35%414%20%20%7%
1701
11th to 20thNight
34%413%26%20%3
1594
21st to endNight
32%5%18%28%16%1
1746
June1st to 10thNight
26%6%17%31%18%1
1620
11th to 20thNight
18%5%19%34%20%4
1620
21st to endNight
28%6%15%29%20%2
1620
July1st to 10thNight
30%7%22%31%10%1
1575
11th to 20thNight
18%6%27%31%16%1
1566
21st to endNight
22%8%28%29%12%1
1673
August1st to 10thNight
14%5%25%36%17%3
1601
11th to 20thNight
27%7%20%28%14%3
1659
21st to endNight
30%9%20%25%13%4
1980
September1st to 10thNight
30%5%16%23%17%9%
1951
11th to 20thNight
35%6%15%19%17%9%
1980
21st to endNight
27%311%21%26%12%
1980
October1st to 10thNight
22%5%8%26%21%18%
2089
11th to 20thNight
30%36%18%25%18%
2160
21st to endNight
31%26%16%26%19%
2376
November1st to 10thNight
31%49%19%26%12%
2220
11th to 20thNight
33%37%19%24%13%
2280
21st to endNight
40%38%16%22%11%
2394
December1st to 10thNight
39%39%19%20%9%
2470
11th to 20thNight
43%26%14%22%13%
3037
21st to endNight
40%26%14%29%9%
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
26%15%39%16%31
270
11th to 20thDay
27%13%36%17%7%1
245
21st to endDay
27%19%37%14%3
264
February1st to 10thDay
28%18%33%17%3
240
11th to 20thDay
38%21%28%12%1
240
21st to endDay
31%24%37%6%3
198
March1st to 10thDay
30%17%35%15%3
240
11th to 20thDay
22%29%33%13%4
240
21st to endDay
23%16%39%17%4
264
April1st to 10thDay
22%16%45%16%1
240
11th to 20thDay
23%17%25%25%10%1
402
21st to endDay
15%12%40%26%5%1
420
May1st to 10thDay
18%10%36%27%8%1
518
11th to 20thDay
15%9%26%33%15%2
625
21st to endDay
11%7%28%33%17%4
679
June1st to 10thDay
7%317%38%28%9%
630
11th to 20thDay
6%218%43%25%6%
630
21st to endDay
8%315%33%30%11%
630
July1st to 10thDay
8%13%31%37%12%
621
11th to 20thDay
318%33%44%12%
618
21st to endDay
418%33%42%11%
684
August1st to 10thDay
5%15%31%46%12%
626
11th to 20thDay
6%1431%46%12%
553
21st to endDay
10%19%16%44%21%
495
September1st to 10thDay
6%5%29%42%18%
294
11th to 20thDay
9%13%31%34%12%
270
21st to endDay
11%212%32%29%14%
270
October1st to 10thDay
7%319%39%25%7%
270
11th to 20thDay
11%6%34%29%15%5%
270
21st to endDay
25%11%27%20%13%3
297
November1st to 10thDay
15%7%30%31%14%3
270
11th to 20thDay
18%13%33%26%7%2
270
21st to endDay
24%16%30%22%6%2
270
December1st to 10thDay
20%10%34%22%11%3
270
11th to 20thDay
29%15%32%19%5%
270
21st to endDay
25%14%40%15%5%1
297
January1st to 10thNight
22%12%33%26%7%
950
11th to 20thNight
25%15%28%25%7%
910
21st to endNight
22%12%34%28%4
990
February1st to 10thNight
23%14%35%24%3
894
11th to 20thNight
28%14%32%23%3
704
21st to endNight
27%14%35%21%2
444
March1st to 10thNight
23%13%34%23%7%
540
11th to 20thNight
20%14%35%25%6%
540
21st to endNight
16%11%41%27%5%
594
April1st to 10thNight
11%13%41%27%7%
540
11th to 20thNight
16%13%36%24%11%
533
21st to endNight
13%12%41%24%10%1
540
May1st to 10thNight
11%9%42%28%9%1
540
11th to 20thNight
13%5%33%34%13%2
531
21st to endNight
10%329%38%17%3
584
June1st to 10thNight
6%115%43%32%4
540
11th to 20thNight
3119%50%24%2
540
21st to endNight
7%112%44%29%6%
540
July1st to 10thNight
5%19%45%34%6%
525
11th to 20thNight
329%44%35%6%
522
21st to endNight
417%42%41%5%
591
August1st to 10thNight
417%47%37%6%
537
11th to 20thNight
7%7%44%37%5%
534
21st to endNight
7%17%35%42%8%
594
September1st to 10thNight
8%9%36%40%6%
540
11th to 20thNight
11%210%28%42%6%
540
21st to endNight
9%39%36%37%5%
540
October1st to 10thNight
6%216%39%31%6%
649
11th to 20thNight
14%6%22%38%18%2
720
21st to endNight
18%8%25%29%18%2
792
November1st to 10thNight
14%426%35%19%2
740
11th to 20thNight
14%10%26%38%12%
760
21st to endNight
20%11%29%27%13%1
874
December1st to 10thNight
21%9%32%29%9%1
950
11th to 20thNight
25%11%29%30%5%
950
21st to endNight
22%14%29%28%7%
1045
Page generated at 2024-01-09 15:24:22. Version ac07

Copyright 2024 Attilla Danko


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