Lake Colorado City State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake Colorado City State Park clear sky chart from 2005-11-05 to 2017-12-20.

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
56%
15952
33%
48116
22%
15912
66%
15912
47%
24274

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
48%
896
34%
2327
16%
895
60%
895
49%
1268
January16th to endNight
48%
797
39%
2333
20%
797
63%
797
47%
1180
February1st to 15thNight
45%
702
32%
2110
17%
699
58%
699
41%
1105
February16th to endNight
37%
632
34%
1894
13%
632
55%
632
44%
960
March1st to 15thNight
39%
681
30%
2121
15%
681
52%
681
38%
1121
March16th to endNight
36%
576
31%
2112
19%
576
53%
576
40%
978
April1st to 15thNight
30%
539
32%
1798
14%
539
53%
539
40%
896
April16th to endNight
37%
540
34%
1800
19%
540
60%
540
47%
838
May1st to 15thNight
39%
539
28%
1626
18%
539
56%
539
44%
844
May16th to endNight
54%
561
28%
1684
19%
561
68%
561
47%
873
June1st to 15thNight
63%
540
25%
1620
21%
540
72%
540
56%
765
June16th to endNight
72%
540
28%
1620
26%
540
77%
540
57%
754
July1st to 15thNight
79%
510
24%
1530
26%
510
81%
510
49%
778
July16th to endNight
88%
564
33%
1611
38%
531
88%
531
57%
748
August1st to 15thNight
89%
539
31%
1789
40%
536
89%
536
54%
798
August16th to endNight
83%
573
30%
1910
34%
573
86%
573
45%
951
September1st to 15thNight
75%
540
27%
1914
30%
540
77%
540
37%
1003
September16th to endNight
68%
537
31%
1980
31%
537
73%
537
35%
1037
October1st to 15thNight
66%
540
37%
1980
35%
540
72%
540
47%
887
October16th to endNight
64%
722
42%
2258
27%
722
74%
722
58%
992
November1st to 15thNight
59%
950
33%
2470
15%
950
67%
950
57%
1269
November16th to endNight
53%
975
38%
2535
18%
975
63%
975
52%
1352
December1st to 15thNight
49%
975
36%
2535
18%
975
59%
975
47%
1414
December16th to endNight
46%
984
35%
2559
17%
984
57%
984
43%
1463

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
6%313323346%59%
48718
Night
6%312323347%62%
48316
Cloud CoverDay
6%313323346%59%
48716
Night
6%312313347%62%
48316
TransparencyDay
25%39%22%25%13%
48418
Night
22%38%22%26%17%
48119
SeeingDay
7%418%33%27%8%
5791
Night
7%427%41%18%1
15961

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
9%413312145%60%
1611
16th to endDay
7%422212345%61%
1902
February1st to 15thDay
6%312212336%65%
1750
16th to endDay
8%42221222465%
1580
March1st to 15thDay
9%413323346%57%
1839
16th to endDay
6%423213336%61%
2112
April1st to 15thDay
5%314323435%62%
2147
16th to endDay
5%313212335%66%
2160
May1st to 15thDay
9%414324347%55%
2325
16th to endDay
7%42342445%6%54%
2430
June1st to 15thDay
2212323347%66%
2340
16th to endDay
421242445%8%58%
2340
July1st to 15thDay
7%213425%46%9%51%
2340
16th to endDay
2212436%5%6%8%56%
2445
August1st to 15thDay
2124345%5%7%61%
2160
16th to endDay
5%3145%45%5%7%9%47%
2292
September1st to 15thDay
8%4244346%6%8%46%
2045
16th to endDay
11%413423446%53%
1980
October1st to 15thDay
7%413322345%61%
1980
16th to endDay
421221222472%
1948
November1st to 15thDay
6%313212246%65%
1718
16th to endDay
7%31221133468%
1755
December1st to 15thDay
11%5%12312346%57%
1755
16th to endDay
8%5%23313335%58%
1764
January1st to 15thNight
9%312213225%64%
2327
16th to endNight
7%312212235%66%
2333
February1st to 15thNight
7%5%13312235%62%
2102
16th to endNight
7%312223336%63%
1894
March1st to 15thNight
9%423323336%58%
2121
16th to endNight
7%412313347%62%
2112
April1st to 15thNight
6%313224236%62%
1798
16th to endNight
5%212212335%67%
1800
May1st to 15thNight
5%313323347%61%
1625
16th to endNight
421222346%10%58%
1683
June1st to 15thNight
11122235%6%8%64%
1620
16th to endNight
21231346%11%62%
1620
July1st to 15thNight
43124144410%58%
1620
16th to endNight
1122145%6%11%61%
1720
August1st to 15thNight
111231345%11%63%
1800
16th to endNight
321332446%9%58%
1910
September1st to 15thNight
8%31432345%10%51%
1914
16th to endNight
8%3144235%6%6%53%
1980
October1st to 15thNight
6%212313246%65%
1980
16th to endNight
221221223375%
2258
November1st to 15thNight
422212246%68%
2470
16th to endNight
7%212212335%66%
2535
December1st to 15thNight
9%413222235%61%
2535
16th to endNight
6%413333445%58%
2559

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
9%413323145%60%
1611
16th to endDay
7%423212345%61%
1902
February1st to 15thDay
6%312213336%65%
1750
16th to endDay
8%42321223464%
1580
March1st to 15thDay
8%313323346%57%
1839
16th to endDay
6%423313337%61%
2110
April1st to 15thDay
5%313323435%62%
2147
16th to endDay
5%31231333466%
2160
May1st to 15thDay
9%423323447%54%
2325
16th to endDay
7%414424446%54%
2430
June1st to 15thDay
3212323347%65%
2340
16th to endDay
421232345%7%59%
2340
July1st to 15thDay
6%213425%46%9%51%
2340
16th to endDay
2212436%46%8%56%
2445
August1st to 15thDay
21124445%47%61%
2160
16th to endDay
5%315%5%35%6%7%8%47%
2292
September1st to 15thDay
9%4243345%7%8%46%
2045
16th to endDay
11%413423446%52%
1980
October1st to 15thDay
7%412323345%61%
1980
16th to endDay
431221232373%
1948
November1st to 15thDay
6%212213247%65%
1718
16th to endDay
7%31121223467%
1755
December1st to 15thDay
11%413312346%57%
1755
16th to endDay
8%423323335%58%
1764
January1st to 15thNight
9%312213235%64%
2327
16th to endNight
7%31221223466%
2333
February1st to 15thNight
7%413313235%62%
2102
16th to endNight
7%312223336%63%
1894
March1st to 15thNight
9%413324335%58%
2121
16th to endNight
7%412312346%62%
2112
April1st to 15thNight
6%313324336%62%
1798
16th to endNight
5%212212345%66%
1800
May1st to 15thNight
5%213323347%61%
1625
16th to endNight
411222346%10%58%
1683
June1st to 15thNight
11122235%6%7%65%
1620
16th to endNight
21231346%10%62%
1620
July1st to 15thNight
42134144410%58%
1620
16th to endNight
12215%5%5%11%62%
1720
August1st to 15thNight
21231346%11%63%
1800
16th to endNight
322332446%9%57%
1910
September1st to 15thNight
8%31342336%10%51%
1914
16th to endNight
9%3144235%5%6%53%
1980
October1st to 15thNight
6%212312246%65%
1980
16th to endNight
221211223375%
2258
November1st to 15thNight
4212212345%68%
2470
16th to endNight
7%212322335%66%
2535
December1st to 15thNight
9%412223235%61%
2535
16th to endNight
6%413333445%58%
2559

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
27%16%22%28%13%
1612
16th to endDay
25%25%16%32%16%
1902
February1st to 15thDay
20%36%22%26%21%
1751
16th to endDay
24%2319%31%19%
1580
March1st to 15thDay
28%26%17%29%16%
1839
16th to endDay
24%37%20%25%18%
2112
April1st to 15thDay
23%27%15%23%25%
2147
16th to endDay
21%26%18%28%22%
2160
May1st to 15thDay
29%47%16%23%18%
2325
16th to endDay
29%49%18%25%12%
2434
June1st to 15thDay
17%411%27%28%10%
2340
16th to endDay
23%413%27%20%11%
2340
July1st to 15thDay
26%5%15%30%17%3
2201
16th to endDay
20%5%15%34%20%3
2291
August1st to 15thDay
21%5%14%27%26%5%
2147
16th to endDay
31%6%14%26%17%4
2292
September1st to 15thDay
32%413%22%21%5%
2045
16th to endDay
31%38%20%24%10%
1980
October1st to 15thDay
26%210%23%23%13%
1980
16th to endDay
17%25%16%34%23%
1948
November1st to 15thDay
20%26%24%28%17%
1718
16th to endDay
21%1418%32%20%
1755
December1st to 15thDay
28%15%20%29%12%
1755
16th to endDay
29%15%22%29%10%
1764
January1st to 15thNight
24%1420%29%19%
2327
16th to endNight
23%2418%29%23%
2333
February1st to 15thNight
26%25%15%25%24%
2112
16th to endNight
23%2416%27%24%
1894
March1st to 15thNight
28%26%16%24%21%
2121
16th to endNight
23%29%23%24%17%
2112
April1st to 15thNight
24%38%19%21%22%
1798
16th to endNight
20%29%18%27%22%
1800
May1st to 15thNight
22%5%11%18%22%19%
1626
16th to endNight
20%6%15%21%22%13%
1685
June1st to 15thNight
16%412%28%27%10%
1620
16th to endNight
15%315%30%23%10%
1620
July1st to 15thNight
23%213%33%21%5%
1530
16th to endNight
15%415%31%29%3
1611
August1st to 15thNight
15%413%28%29%8%
1789
16th to endNight
21%5%14%27%24%6%
1910
September1st to 15thNight
28%412%26%20%8%
1914
16th to endNight
29%49%20%22%13%
1980
October1st to 15thNight
20%211%25%22%15%
1980
16th to endNight
15%15%18%33%26%
2258
November1st to 15thNight
18%27%26%25%20%
2470
16th to endNight
21%2413%33%24%
2535
December1st to 15thNight
26%15%19%27%18%
2535
16th to endNight
27%2421%26%17%
2559

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
18%326%30%15%5%
90
16th to endDay
5%10%27%35%16%5%
96
February1st to 15thDay
6%5%27%32%23%4
90
16th to endDay
8%237%27%20%3
81
March1st to 15thDay
12%242%28%13%1
90
16th to endDay
26%32%34%18%6%
96
April1st to 15thDay
7%13%45%27%6%
266
16th to endDay
6%17%38%24%8%4
270
May1st to 15thDay
12%7%34%33%10%1
462
16th to endDay
12%5%29%37%13%1
517
June1st to 15thDay
5%116%49%23%3
495
16th to endDay
5%111%37%34%9%
495
July1st to 15thDay
7%1437%40%8%
475
16th to endDay
2228%49%16%
494
August1st to 15thDay
324%47%22%
315
16th to endDay
6%6%34%34%17%
332
September1st to 15thDay
31428%41%22%
200
16th to endDay
21%222%31%20%
135
October1st to 15thDay
5%8%34%43%6%
135
16th to endDay
6%122%31%27%10%
144
November1st to 15thDay
17%119%32%20%8%
135
16th to endDay
13%11%24%22%16%11%
135
December1st to 15thDay
14%6%25%28%20%3
135
16th to endDay
10%12%29%33%14%
108
January1st to 15thNight
12%5%30%39%12%
900
16th to endNight
8%7%32%41%9%
797
February1st to 15thNight
9%7%33%39%10%
704
16th to endNight
8%9%40%36%4
632
March1st to 15thNight
12%7%37%37%5%
681
16th to endNight
9%7%44%32%5%
576
April1st to 15thNight
7%8%51%29%3
539
16th to endNight
7%7%45%35%4
540
May1st to 15thNight
6%5%45%37%4
540
16th to endNight
6%234%45%11%
563
June1st to 15thNight
2129%50%15%
540
16th to endNight
3118%52%23%
540
July1st to 15thNight
6%6%51%33%1
510
16th to endNight
2446%43%2
564
August1st to 15thNight
1140%53%3
539
16th to endNight
31440%45%4
573
September1st to 15thNight
10%6%38%40%3
540
16th to endNight
11%11%46%29%
537
October1st to 15thNight
6%122%47%20%
540
16th to endNight
4424%42%22%1
722
November1st to 15thNight
6%326%42%19%1
950
16th to endNight
8%429%38%17%1
975
December1st to 15thNight
12%431%40%12%
975
16th to endNight
9%7%33%39%9%
984
Page generated at 2017-12-21 06:04:44. Version ac04

Copyright 2017 A. Danko


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