Lake Brownwood State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake Brownwood State Park clear sky chart from 2005-11-05 to

2017-09-12
.

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
53%
15515
30%
46892
21%
15472
62%
15472
42%
24931

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
42%
896
31%
2327
14%
895
52%
895
42%
1338
January16th to endNight
42%
882
35%
2418
16%
882
56%
882
43%
1325
February1st to 15thNight
37%
704
30%
2108
14%
698
51%
698
39%
1150
February16th to endNight
30%
632
33%
1894
11%
632
47%
632
39%
1012
March1st to 15thNight
34%
605
28%
2045
14%
605
49%
605
32%
1121
March16th to endNight
36%
576
28%
2112
18%
576
52%
576
35%
1052
April1st to 15thNight
29%
539
27%
1938
12%
539
51%
539
35%
971
April16th to endNight
34%
540
30%
1722
14%
540
54%
540
39%
912
May1st to 15thNight
37%
539
25%
1620
16%
539
51%
539
36%
927
May16th to endNight
49%
561
26%
1684
19%
561
62%
561
39%
949
June1st to 15thNight
68%
540
24%
1620
24%
540
74%
540
54%
771
June16th to endNight
70%
540
27%
1620
30%
540
74%
540
48%
837
July1st to 15thNight
80%
510
25%
1530
27%
510
82%
510
49%
778
July16th to endNight
87%
564
32%
1594
39%
531
89%
531
55%
769
August1st to 15thNight
89%
539
34%
1685
41%
536
90%
536
58%
762
August16th to endNight
83%
573
28%
1920
34%
573
83%
573
40%
999
September1st to 15thNight
74%
530
23%
1943
28%
530
75%
530
34%
1053
September16th to endNight
72%
492
31%
1815
32%
492
76%
492
38%
919
October1st to 15thNight
68%
495
37%
1815
36%
495
74%
495
45%
848
October16th to endNight
58%
690
37%
2098
24%
690
66%
690
50%
1024
November1st to 15thNight
56%
808
31%
2208
16%
808
63%
808
48%
1167
November16th to endNight
46%
900
33%
2340
16%
900
56%
900
45%
1335
December1st to 15thNight
45%
900
32%
2340
16%
900
53%
900
39%
1393
December16th to endNight
40%
960
29%
2496
13%
960
49%
960
38%
1519

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%423324446%55%
47759
Night
7%313323347%59%
47092
Cloud CoverDay
8%423424446%55%
47757
Night
7%313323347%59%
47092
TransparencyDay
29%5%10%21%22%10%
47457
Night
24%410%21%24%14%
46897
SeeingDay
8%420%31%26%8%
5482
Night
9%5%29%38%17%1
15522

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
12%423322225%57%
1611
16th to endDay
11%314213445%57%
1815
February1st to 15thDay
9%424222436%57%
1750
16th to endDay
11%5%13313225%59%
1580
March1st to 15thDay
12%6%23213346%52%
1914
16th to endDay
9%334323235%57%
2112
April1st to 15thDay
6%424324446%56%
2007
16th to endDay
9%5%24423345%55%
2237
May1st to 15thDay
11%5%24434446%48%
2331
16th to endDay
10%5%2443446%8%46%
2430
June1st to 15thDay
421242445%7%61%
2340
16th to endDay
6%313425%45%9%53%
2340
July1st to 15thDay
5%3145%35%6%6%8%49%
2340
16th to endDay
42125%35%5%6%10%53%
2466
August1st to 15thDay
2112335%5%5%8%60%
2262
16th to endDay
6%325%6%35%5%7%8%44%
2280
September1st to 15thDay
8%425%435%447%49%
1936
16th to endDay
8%324424446%53%
1815
October1st to 15thDay
8%312312345%61%
1815
16th to endDay
6%31211122470%
1763
November1st to 15thDay
7%313322345%61%
1647
16th to endDay
10%41331222463%
1620
December1st to 15thDay
13%5%24322325%53%
1620
16th to endDay
11%6%13313446%51%
1728
January1st to 15thNight
11%423222235%60%
2327
16th to endNight
10%41121334462%
2418
February1st to 15thNight
9%5%24313225%60%
2102
16th to endNight
10%412213246%59%
1894
March1st to 15thNight
12%313324436%54%
2045
16th to endNight
9%212323346%59%
2112
April1st to 15thNight
5%32342346%7%57%
1938
16th to endNight
6%323323346%60%
1722
May1st to 15thNight
8%41442345%8%53%
1619
16th to endNight
6%32322445%10%53%
1683
June1st to 15thNight
21232335%8%66%
1620
16th to endNight
421231345%10%60%
1620
July1st to 15thNight
411132346%10%59%
1620
16th to endNight
21222346%11%60%
1702
August1st to 15thNight
112322347%70%
1695
16th to endNight
5%2133245%6%10%54%
1920
September1st to 15thNight
8%31342445%8%52%
1943
16th to endNight
7%21432335%8%55%
1815
October1st to 15thNight
6%312213246%64%
1815
16th to endNight
7%31221123469%
2098
November1st to 15thNight
5%212313345%64%
2208
16th to endNight
10%31332223461%
2340
December1st to 15thNight
11%414322346%55%
2340
16th to endNight
10%5%14333345%54%
2496

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
12%41332223457%
1611
16th to endDay
11%313313445%57%
1815
February1st to 15thDay
9%423312436%57%
1750
16th to endDay
11%5%23312225%59%
1580
March1st to 15thDay
12%6%23223346%52%
1914
16th to endDay
9%424323335%57%
2110
April1st to 15thDay
6%424324346%56%
2007
16th to endDay
9%433423345%54%
2237
May1st to 15thDay
11%5%2443445%6%48%
2331
16th to endDay
9%5%3443446%8%45%
2430
June1st to 15thDay
421242445%6%61%
2340
16th to endDay
6%21343445%9%53%
2340
July1st to 15thDay
5%315%5%26%5%6%8%48%
2340
16th to endDay
42135%25%5%5%10%53%
2466
August1st to 15thDay
2112335%5%5%9%59%
2262
16th to endDay
6%325%6%35%5%6%9%44%
2280
September1st to 15thDay
9%425%435%446%48%
1936
16th to endDay
8%3144235%46%53%
1815
October1st to 15thDay
7%313323345%60%
1815
16th to endDay
6%31211122470%
1763
November1st to 15thDay
7%413312345%61%
1647
16th to endDay
10%42231123463%
1620
December1st to 15thDay
13%5%23423325%53%
1620
16th to endDay
11%7%1331345%6%51%
1728
January1st to 15thNight
11%324212235%60%
2327
16th to endNight
10%41121334462%
2418
February1st to 15thNight
9%42431222460%
2102
16th to endNight
10%412213246%59%
1894
March1st to 15thNight
12%4233235%36%54%
2045
16th to endNight
9%213323346%59%
2112
April1st to 15thNight
5%32342346%7%56%
1938
16th to endNight
6%324323346%60%
1722
May1st to 15thNight
8%32442345%8%52%
1619
16th to endNight
6%323325%45%10%53%
1683
June1st to 15thNight
211131336%8%65%
1620
16th to endNight
421231345%9%60%
1620
July1st to 15thNight
411132346%10%59%
1620
16th to endNight
211232346%11%60%
1702
August1st to 15thNight
1232325%7%69%
1695
16th to endNight
5%21332447%10%54%
1920
September1st to 15thNight
8%31342345%9%52%
1943
16th to endNight
7%31332346%8%55%
1815
October1st to 15thNight
7%312212346%64%
1815
16th to endNight
7%312211235%69%
2098
November1st to 15thNight
5%212323345%64%
2208
16th to endNight
10%31332223461%
2340
December1st to 15thNight
11%324312445%55%
2340
16th to endNight
10%5%24333345%54%
2496

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
31%16%17%29%12%
1612
16th to endDay
29%27%17%27%15%
1815
February1st to 15thDay
27%36%18%23%19%
1751
16th to endDay
30%3418%26%17%
1580
March1st to 15thDay
34%49%12%25%13%
1914
16th to endDay
30%38%21%24%11%
2112
April1st to 15thDay
28%5%9%20%18%16%
2007
16th to endDay
31%5%6%17%25%13%
2237
May1st to 15thDay
37%5%9%18%17%10%
2331
16th to endDay
35%7%11%20%20%4
2434
June1st to 15thDay
21%6%13%25%26%6%
2340
16th to endDay
28%7%12%26%17%7%
2340
July1st to 15thDay
29%7%17%26%16%1
2201
16th to endDay
23%6%18%33%15%2
2311
August1st to 15thDay
21%6%15%32%20%3
2248
16th to endDay
35%7%14%24%15%2
2280
September1st to 15thDay
34%6%12%19%21%6%
1936
16th to endDay
29%5%9%20%23%11%
1815
October1st to 15thDay
25%410%21%24%13%
1815
16th to endDay
19%35%19%31%20%
1763
November1st to 15thDay
26%38%25%23%13%
1647
16th to endDay
26%25%16%28%20%
1620
December1st to 15thDay
35%25%16%26%12%
1620
16th to endDay
33%47%19%26%9%
1728
January1st to 15thNight
28%15%18%25%19%
2327
16th to endNight
25%35%16%27%20%
2418
February1st to 15thNight
28%37%14%23%23%
2112
16th to endNight
27%36%17%25%19%
1894
March1st to 15thNight
30%49%15%22%16%
2045
16th to endNight
25%411%20%25%11%
2112
April1st to 15thNight
24%6%11%18%20%19%
1938
16th to endNight
25%5%11%18%25%13%
1722
May1st to 15thNight
30%5%11%22%18%12%
1620
16th to endNight
25%8%15%23%19%6%
1685
June1st to 15thNight
16%415%31%25%6%
1620
16th to endNight
20%5%12%30%24%6%
1620
July1st to 15thNight
18%7%17%32%20%3
1530
16th to endNight
14%6%19%33%21%3
1594
August1st to 15thNight
14%414%32%29%4
1685
16th to endNight
23%7%16%28%19%5%
1920
September1st to 15thNight
28%7%11%23%21%7%
1943
16th to endNight
25%5%10%20%23%13%
1815
October1st to 15thNight
20%411%25%21%15%
1815
16th to endNight
19%35%16%30%23%
2098
November1st to 15thNight
21%47%25%23%18%
2208
16th to endNight
27%26%15%25%22%
2340
December1st to 15thNight
30%37%19%25%13%
2340
16th to endNight
32%46%16%25%14%
2496

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
15%13%26%31%12%1
90
16th to endDay
10%9%41%26%10%2
96
February1st to 15thDay
5%12%36%33%11%1
90
16th to endDay
14%344%32%13
81
March1st to 15thDay
16%12%30%28%12%
90
16th to endDay
6%9%34%33%15%1
96
April1st to 15thDay
7%14%44%26%7%
126
16th to endDay
12%11%43%22%9%
347
May1st to 15thDay
14%8%37%30%7%1
468
16th to endDay
13%5%29%32%16%1
517
June1st to 15thDay
4117%46%25%4
495
16th to endDay
5%12%39%33%8%
495
July1st to 15thDay
5%7%38%40%7%
475
16th to endDay
3426%46%19%
515
August1st to 15thDay
3321%48%22%
416
16th to endDay
8%7%32%36%14%
320
September1st to 15thDay
4117%39%34%
123
16th to endDay
7%1211%51%26%
90
October1st to 15thDay
25%35%43%13%
90
16th to endDay
10%422%25%32%5%
96
November1st to 15thDay
15%5%27%33%14%3
90
16th to endDay
22%15%23%26%11%1
90
December1st to 15thDay
22%5%26%28%10%6%
90
16th to endDay
14%12%43%21%7%
96
January1st to 15thNight
13%8%30%37%8%
900
16th to endNight
12%8%34%37%7%
882
February1st to 15thNight
12%7%39%33%6%
704
16th to endNight
13%9%45%28%3
632
March1st to 15thNight
12%8%42%30%5%
605
16th to endNight
9%9%44%32%5%
576
April1st to 15thNight
5%8%54%27%3
539
16th to endNight
6%6%50%28%7%
540
May1st to 15thNight
9%7%43%32%6%
540
16th to endNight
6%238%38%14%
563
June1st to 15thNight
3123%51%19%1
540
16th to endNight
417%51%24%1
540
July1st to 15thNight
5%8%50%31%2
510
16th to endNight
3347%42%2
564
August1st to 15thNight
1337%55%2
539
16th to endNight
6%340%43%5%
573
September1st to 15thNight
8%6%41%38%3
530
16th to endNight
7%110%45%32%2
492
October1st to 15thNight
7%121%43%25%1
495
16th to endNight
9%425%38%21%1
690
November1st to 15thNight
7%429%40%17%
808
16th to endNight
12%6%31%36%12%
900
December1st to 15thNight
13%6%31%38%9%
900
16th to endNight
13%7%36%34%8%
960
Page generated at 2017-09-13 06:39:21. Version ac04

Copyright 2017 A. Danko


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