Martin Dies, Jr. State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Martin Dies, Jr. State Park clear sky chart from 2005-11-05 to 2018-08-29.

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
50%
16657
24%
50607
17%
16610
57%
16610
30%
30476

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
33%
975
23%
2522
11%
970
40%
970
27%
1679
January16th to endNight
30%
1040
25%
2704
9%
1040
39%
1040
27%
1802
February1st to 15thNight
28%
935
22%
2463
8%
931
37%
931
26%
1640
February16th to endNight
24%
513
25%
1879
10%
513
40%
513
19%
1172
March1st to 15thNight
29%
585
25%
2145
14%
585
42%
585
21%
1311
March16th to endNight
37%
624
21%
2288
16%
624
47%
624
25%
1341
April1st to 15thNight
34%
584
22%
2041
13%
584
47%
584
25%
1205
April16th to endNight
41%
579
23%
1928
17%
579
51%
579
27%
1147
May1st to 15thNight
41%
584
20%
1918
16%
584
50%
584
27%
1159
May16th to endNight
61%
611
25%
1828
23%
609
67%
609
40%
1019
June1st to 15thNight
77%
585
20%
1755
21%
585
81%
585
44%
942
June16th to endNight
72%
585
18%
1755
19%
585
75%
585
35%
1038
July1st to 15thNight
80%
555
16%
1665
19%
555
81%
555
38%
973
July16th to endNight
81%
612
17%
1738
20%
579
83%
579
38%
993
August1st to 15thNight
88%
575
25%
1763
29%
572
89%
572
50%
871
August16th to endNight
72%
615
14%
2050
17%
615
72%
615
26%
1297
September1st to 15thNight
71%
540
18%
1882
19%
540
72%
540
29%
1092
September16th to endNight
71%
537
29%
1980
32%
537
73%
537
30%
1101
October1st to 15thNight
69%
711
31%
2151
25%
711
72%
711
42%
1142
October16th to endNight
57%
768
37%
2304
25%
768
66%
768
42%
1209
November1st to 15thNight
51%
760
27%
2280
20%
760
56%
760
34%
1326
November16th to endNight
45%
780
33%
2340
21%
780
56%
780
34%
1338
December1st to 15thNight
38%
964
24%
2524
12%
964
44%
964
25%
1749
December16th to endNight
30%
1040
19%
2704
8%
1040
36%
1040
21%
1930

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%5%25%5%35%5%5%7%39%
51636
Night
12%5%2432345%7%48%
50803
TransparencyDay
42%6%10%17%16%6%
51336
Night
34%5%12%19%18%8%
50608
SeeingDay
12%418%25%26%12%
6705
Night
15%6%22%31%20%3
16658

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 15thDay
19%6%23423245%44%
1746
16th to endDay
20%6%24323345%43%
1872
February1st to 15thDay
18%7%345%3423441%
1736
16th to endDay
19%7%35%424335%38%
1881
March1st to 15thDay
22%7%35%413235%39%
2145
16th to endDay
15%6%35%5%24445%42%
2286
April1st to 15thDay
14%6%35%5%345%5%5%40%
2237
16th to endDay
12%5%35%6%36%46%6%39%
2307
May1st to 15thDay
12%6%36%6%35%5%5%7%36%
2360
16th to endDay
8%435%6%47%6%7%9%36%
2638
June1st to 15thDay
6%426%7%48%6%8%10%33%
2535
16th to endDay
9%5%25%7%5%8%7%8%10%27%
2535
July1st to 15thDay
9%425%8%5%8%7%7%10%30%
2535
16th to endDay
7%5%37%7%47%8%7%9%32%
2674
August1st to 15thDay
4225%6%47%6%8%11%39%
2439
16th to endDay
10%5%26%6%5%8%7%6%8%32%
2448
September1st to 15thDay
12%425%6%46%6%5%7%38%
2074
16th to endDay
8%326%7%45%5%6%7%42%
1974
October1st to 15thDay
9%324434347%52%
1800
16th to endDay
12%313323335%59%
1920
November1st to 15thDay
9%5%26%5%2435%7%47%
1908
16th to endDay
13%5%2442333451%
1950
December1st to 15thDay
18%9%35%42334439%
1764
16th to endDay
19%10%46%5%23335%34%
1872
January1st to 15thNight
17%8%25%323335%44%
2522
16th to endNight
20%7%23322335%45%
2704
February1st to 15thNight
17%7%24422336%43%
2453
16th to endNight
16%7%25%32333443%
1879
March1st to 15thNight
19%6%25%323336%44%
2145
16th to endNight
11%6%34424347%47%
2288
April1st to 15thNight
11%5%24325%45%8%45%
2041
16th to endNight
12%5%2443435%8%46%
1928
May1st to 15thNight
10%5%3442445%9%43%
1917
16th to endNight
7%41332336%10%52%
1827
June1st to 15thNight
231332346%10%57%
1755
16th to endNight
5%313425%5%7%11%47%
1755
July1st to 15thNight
6%3124145%7%13%47%
1755
16th to endNight
3224425%5%8%12%47%
1846
August1st to 15thNight
211221347%13%59%
1773
16th to endNight
8%425%5%35%5%8%11%39%
2050
September1st to 15thNight
9%425%42447%8%46%
1882
16th to endNight
7%5%2343446%7%50%
1980
October1st to 15thNight
6%21332345%6%59%
2151
16th to endNight
10%31232234462%
2304
November1st to 15thNight
9%42442435%6%51%
2280
16th to endNight
13%5%13322335%55%
2340
December1st to 15thNight
18%8%25%413345%41%
2524
16th to endNight
20%9%35%423345%37%
2704

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
42%3416%22%10%
1747
16th to endDay
43%35%14%22%11%
1872
February1st to 15thDay
48%25%15%19%9%
1737
16th to endDay
48%46%13%18%8%
1881
March1st to 15thDay
48%37%13%21%6%
2145
16th to endDay
43%48%16%22%5%
2288
April1st to 15thDay
45%46%15%18%8%
2237
16th to endDay
42%6%9%15%19%6%
2307
May1st to 15thDay
46%6%9%16%14%6%
2360
16th to endDay
40%8%13%21%14%1
2642
June1st to 15thDay
42%9%13%19%15%
2535
16th to endDay
46%9%15%17%9%
2535
July1st to 15thDay
44%10%17%19%8%
2396
16th to endDay
42%11%17%22%6%
2519
August1st to 15thDay
34%9%20%26%9%
2425
16th to endDay
46%11%16%17%7%1
2448
September1st to 15thDay
43%7%15%16%12%5%
2074
16th to endDay
38%8%10%18%17%6%
1974
October1st to 15thDay
32%49%21%16%14%
1800
16th to endDay
29%3413%32%16%
1920
November1st to 15thDay
37%5%9%18%20%8%
1908
16th to endDay
36%45%14%26%12%
1950
December1st to 15thDay
48%37%17%15%6%
1764
16th to endDay
52%36%17%15%5%
1872
January1st to 15thNight
42%26%15%21%11%
2522
16th to endNight
43%2414%20%13%
2704
February1st to 15thNight
43%26%15%19%11%
2463
16th to endNight
44%46%15%17%11%
1879
March1st to 15thNight
42%38%14%20%10%
2145
16th to endNight
37%5%11%16%22%6%
2288
April1st to 15thNight
36%5%9%20%16%10%
2041
16th to endNight
35%6%10%19%18%9%
1928
May1st to 15thNight
36%6%13%17%18%7%
1918
16th to endNight
27%5%17%28%18%2
1829
June1st to 15thNight
22%7%16%34%18%1
1755
16th to endNight
27%10%20%27%12%
1755
July1st to 15thNight
25%11%30%23%9%
1665
16th to endNight
24%10%31%25%8%
1738
August1st to 15thNight
15%8%28%33%12%1
1763
16th to endNight
36%10%24%18%8%2
2050
September1st to 15thNight
33%7%20%19%12%5%
1882
16th to endNight
31%6%13%19%19%9%
1980
October1st to 15thNight
24%5%9%25%18%15%
2151
16th to endNight
26%25%14%29%21%
2304
November1st to 15thNight
32%412%20%22%7%
2280
16th to endNight
32%37%14%27%14%
2340
December1st to 15thNight
45%46%19%14%9%
2524
16th to endNight
49%45%14%17%7%
2704

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
24%11%37%15%8%2
135
16th to endDay
20%21%36%15%4
144
February1st to 15thDay
20%14%40%22%1
135
16th to endDay
25%22%37%13%1
120
March1st to 15thDay
25%13%47%7%6%
135
16th to endDay
18%13%38%21%6%
144
April1st to 15thDay
16%12%35%23%11%1
236
16th to endDay
20%7%26%28%13%3
319
May1st to 15thDay
18%427%31%15%2
377
16th to endDay
8%424%34%22%5%
597
June1st to 15thDay
8%13%35%32%10%
570
16th to endDay
10%111%29%33%14%
570
July1st to 15thDay
8%17%26%35%21%
550
16th to endDay
5%5%22%43%23%
595
August1st to 15thDay
7%318%47%22%
502
16th to endDay
13%1315%36%28%
384
September1st to 15thDay
46%24%40%23%
229
16th to endDay
5%15%30%43%13%
135
October1st to 15thDay
215%40%24%17%
135
16th to endDay
18%424%18%25%9%
144
November1st to 15thDay
8%437%31%16%1
135
16th to endDay
17%6%35%28%6%5%
135
December1st to 15thDay
27%5%30%21%7%7%
135
16th to endDay
30%16%33%17%1
144
January1st to 15thNight
22%12%27%28%8%
975
16th to endNight
24%10%30%28%4
1040
February1st to 15thNight
23%11%31%27%5%
935
16th to endNight
22%12%38%23%2
513
March1st to 15thNight
24%9%33%27%5%
585
16th to endNight
14%8%36%29%10%
624
April1st to 15thNight
15%7%39%28%8%
584
16th to endNight
15%6%32%32%12%
579
May1st to 15thNight
15%434%32%12%1
585
16th to endNight
8%223%38%23%3
611
June1st to 15thNight
410%45%34%5%
585
16th to endNight
6%11%37%37%6%
585
July1st to 15thNight
5%437%39%12%
555
16th to endNight
3429%53%8%
612
August1st to 15thNight
2335%48%9%
575
16th to endNight
9%1429%43%11%
615
September1st to 15thNight
10%17%29%40%11%
540
16th to endNight
11%18%29%39%9%
537
October1st to 15thNight
7%214%36%34%5%
711
16th to endNight
11%5%21%33%25%2
768
November1st to 15thNight
10%7%26%33%20%1
760
16th to endNight
16%7%26%32%15%
780
December1st to 15thNight
24%8%25%29%11%
964
16th to endNight
26%10%28%27%6%
1040
Page generated at 2018-08-30 04:34:19. Version ac04

Copyright 2018 A. Danko


Martin Dies, Jr. State Park Clear Sky Chart |Charts Home