Colorado Bend State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Colorado Bend State Park clear sky chart from 2005-11-05 to 2018-01-12.

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
50%
15982
28%
48378
19%
15936
59%
15936
39%
26559

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
37%
954
28%
2472
11%
951
47%
951
39%
1472
January16th to endNight
36%
891
33%
2427
14%
891
49%
891
37%
1420
February1st to 15thNight
34%
704
29%
2106
12%
698
48%
698
35%
1160
February16th to endNight
24%
632
31%
1894
9%
632
42%
632
35%
1047
March1st to 15thNight
34%
579
28%
2019
14%
579
49%
579
29%
1133
March16th to endNight
32%
576
27%
2112
15%
576
48%
576
31%
1108
April1st to 15thNight
27%
539
26%
1977
12%
539
48%
539
31%
1056
April16th to endNight
29%
540
27%
1724
13%
540
48%
540
33%
978
May1st to 15thNight
32%
539
24%
1620
14%
539
48%
539
34%
941
May16th to endNight
47%
562
25%
1684
18%
561
59%
561
37%
961
June1st to 15thNight
67%
540
23%
1620
23%
540
73%
540
52%
794
June16th to endNight
73%
540
25%
1620
27%
540
76%
540
43%
880
July1st to 15thNight
79%
510
24%
1530
25%
510
82%
510
48%
788
July16th to endNight
86%
564
30%
1594
35%
531
88%
531
54%
776
August1st to 15thNight
89%
539
33%
1667
39%
536
90%
536
59%
752
August16th to endNight
75%
573
23%
1949
29%
573
76%
573
35%
1062
September1st to 15thNight
76%
540
21%
1980
25%
540
77%
540
35%
1054
September16th to endNight
72%
537
30%
1980
29%
537
75%
537
33%
1062
October1st to 15thNight
68%
540
34%
1980
31%
540
74%
540
43%
933
October16th to endNight
55%
768
36%
2304
22%
768
64%
768
47%
1170
November1st to 15thNight
51%
825
29%
2345
17%
825
58%
825
41%
1316
November16th to endNight
48%
975
34%
2535
16%
975
57%
975
44%
1440
December1st to 15thNight
43%
975
29%
2535
15%
975
50%
975
37%
1566
December16th to endNight
37%
1040
27%
2704
11%
1040
46%
1040
34%
1690

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
9%42442445%6%51%
48949
Night
8%413323347%56%
48580
Cloud CoverDay
9%42442445%6%51%
48947
Night
8%313323347%56%
48580
TransparencyDay
32%5%10%20%21%10%
48647
Night
27%411%21%21%13%
48385
SeeingDay
9%5%20%32%25%6%
5795
Night
10%5%29%37%15%1
15986

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
13%6%24223235%53%
1710
16th to endDay
13%313223346%55%
1806
February1st to 15thDay
10%6%34312245%57%
1750
16th to endDay
12%5%23223345%54%
1580
March1st to 15thDay
14%6%24323435%49%
1941
16th to endDay
11%5%34323335%52%
2112
April1st to 15thDay
9%5%25%43435%5%49%
1971
16th to endDay
12%5%34424445%49%
2232
May1st to 15thDay
11%6%36%5%3436%6%41%
2331
16th to endDay
11%6%35%5%35%5%6%7%39%
2430
June1st to 15thDay
42134345%5%10%55%
2340
16th to endDay
7%3245%45%5%6%8%45%
2340
July1st to 15thDay
6%3235%36%6%6%9%46%
2340
16th to endDay
5%313435%5%6%10%50%
2466
August1st to 15thDay
2112325%46%8%60%
2280
16th to endDay
7%416%6%37%6%6%9%41%
2251
September1st to 15thDay
8%5%25%5%345%5%6%47%
1980
16th to endDay
9%3245%25%35%7%48%
1980
October1st to 15thDay
7%424323336%57%
1965
16th to endDay
7%21221322468%
1920
November1st to 15thDay
10%5%2442345%5%51%
1842
16th to endDay
9%41431222461%
1755
December1st to 15thDay
13%5%35%313335%51%
1755
16th to endDay
11%8%25%42335%6%45%
1872
January1st to 15thNight
11%5%24312335%56%
2472
16th to endNight
13%413322245%55%
2427
February1st to 15thNight
9%5%14313235%58%
2102
16th to endNight
11%422312346%56%
1894
March1st to 15thNight
12%414323447%50%
2019
16th to endNight
9%415%413336%56%
2112
April1st to 15thNight
7%4245%24446%54%
1977
16th to endNight
8%42442335%6%53%
1724
May1st to 15thNight
8%41343435%9%50%
1619
16th to endNight
6%41342446%10%50%
1683
June1st to 15thNight
1213223448%65%
1620
16th to endNight
42123345%6%9%57%
1620
July1st to 15thNight
41123234410%59%
1620
16th to endNight
31221435%14%59%
1702
August1st to 15thNight
211121235%8%68%
1677
16th to endNight
6%31442446%10%50%
1949
September1st to 15thNight
8%31332446%8%52%
1980
16th to endNight
8%41432435%9%51%
1980
October1st to 15thNight
7%212313346%63%
1980
16th to endNight
7%21231333465%
2304
November1st to 15thNight
7%5%23423245%59%
2345
16th to endNight
9%413313335%61%
2535
December1st to 15thNight
11%5%24323346%52%
2535
16th to endNight
12%6%24323345%51%
2704

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
13%6%14322245%53%
1710
16th to endDay
12%313213345%55%
1806
February1st to 15thDay
10%5%34312236%57%
1750
16th to endDay
12%5%23322345%54%
1580
March1st to 15thDay
14%6%24323445%49%
1941
16th to endDay
11%5%24423345%52%
2110
April1st to 15thDay
9%5%3442435%6%49%
1971
16th to endDay
11%5%345%23445%49%
2232
May1st to 15thDay
11%6%36%5%35%36%7%41%
2331
16th to endDay
10%6%35%5%36%46%7%39%
2430
June1st to 15thDay
42134245%5%9%55%
2340
16th to endDay
7%3245%36%5%6%9%45%
2340
July1st to 15thDay
6%3235%35%6%5%8%47%
2340
16th to endDay
5%3234246%6%10%50%
2466
August1st to 15thDay
211333446%8%60%
2280
16th to endDay
7%5%15%6%37%5%6%9%41%
2251
September1st to 15thDay
8%5%25%5%4445%6%47%
1980
16th to endDay
10%315%43445%7%48%
1980
October1st to 15thDay
6%424323336%57%
1965
16th to endDay
7%21221323469%
1920
November1st to 15thDay
10%42442435%5%51%
1842
16th to endDay
9%41441222461%
1755
December1st to 15thDay
13%6%24323335%51%
1755
16th to endDay
11%7%35%42335%6%46%
1872
January1st to 15thNight
11%5%24312335%56%
2472
16th to endNight
12%423322335%56%
2427
February1st to 15thNight
9%5%24313235%58%
2102
16th to endNight
11%413313345%57%
1894
March1st to 15thNight
12%424323437%50%
2019
16th to endNight
8%424413336%56%
2112
April1st to 15thNight
6%4245%24446%54%
1977
16th to endNight
8%42442335%7%52%
1724
May1st to 15thNight
8%413335%36%8%50%
1619
16th to endNight
6%42432447%10%50%
1683
June1st to 15thNight
1113223449%64%
1620
16th to endNight
421232446%9%57%
1620
July1st to 15thNight
421232345%10%58%
1620
16th to endNight
311221345%13%60%
1702
August1st to 15thNight
21221235%8%68%
1677
16th to endNight
6%31442447%11%50%
1949
September1st to 15thNight
8%32342446%8%52%
1980
16th to endNight
9%31332445%9%51%
1980
October1st to 15thNight
7%212323346%63%
1980
16th to endNight
6%21331333465%
2304
November1st to 15thNight
6%414423335%59%
2345
16th to endNight
9%413313235%61%
2535
December1st to 15thNight
11%5%24323346%52%
2535
16th to endNight
12%6%24322345%51%
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
34%25%19%25%12%
1711
16th to endDay
31%36%14%27%16%
1806
February1st to 15thDay
30%27%16%22%20%
1751
16th to endDay
32%35%18%24%15%
1580
March1st to 15thDay
38%38%12%22%14%
1941
16th to endDay
35%38%18%23%10%
2112
April1st to 15thDay
35%38%17%18%15%
1971
16th to endDay
36%46%18%21%11%
2232
May1st to 15thDay
42%410%14%17%9%
2331
16th to endDay
41%6%10%19%17%3
2434
June1st to 15thDay
24%6%12%25%24%7%
2340
16th to endDay
33%6%13%22%18%5%
2340
July1st to 15thDay
29%7%16%27%16%2
2201
16th to endDay
23%8%18%29%17%1
2311
August1st to 15thDay
19%6%15%35%20%2
2266
16th to endDay
36%8%14%26%11%2
2251
September1st to 15thDay
36%6%11%22%18%5%
1980
16th to endDay
34%5%9%20%20%9%
1980
October1st to 15thDay
28%411%21%20%14%
1965
16th to endDay
22%2417%31%22%
1920
November1st to 15thDay
33%48%22%20%10%
1842
16th to endDay
28%25%16%24%21%
1755
December1st to 15thDay
36%47%17%22%11%
1755
16th to endDay
38%38%16%22%10%
1872
January1st to 15thNight
31%26%17%24%17%
2472
16th to endNight
31%35%15%25%19%
2427
February1st to 15thNight
29%37%13%23%22%
2112
16th to endNight
29%36%17%22%19%
1894
March1st to 15thNight
33%49%12%24%15%
2019
16th to endNight
30%310%19%23%11%
2112
April1st to 15thNight
31%48%18%19%17%
1977
16th to endNight
31%411%18%21%12%
1724
May1st to 15thNight
30%5%12%22%19%9%
1620
16th to endNight
29%6%15%27%17%3
1685
June1st to 15thNight
17%5%15%28%26%6%
1620
16th to endNight
23%7%14%28%21%4
1620
July1st to 15thNight
20%6%21%32%17%1
1530
16th to endNight
16%6%23%35%17%1
1594
August1st to 15thNight
13%418%37%22%3
1667
16th to endNight
27%7%20%27%12%4
1949
September1st to 15thNight
28%6%16%23%19%6%
1980
16th to endNight
30%5%11%24%18%10%
1980
October1st to 15thNight
22%313%26%18%15%
1980
16th to endNight
22%35%15%27%25%
2304
November1st to 15thNight
28%38%23%22%13%
2345
16th to endNight
26%27%16%24%21%
2535
December1st to 15thNight
33%39%16%22%13%
2535
16th to endNight
36%27%15%24%13%
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
17%8%35%30%8%
123
16th to endDay
10%15%41%22%8%1
96
February1st to 15thDay
5%11%38%34%10%
90
16th to endDay
13%12%45%23%4
81
March1st to 15thDay
24%10%32%25%6%1
90
16th to endDay
4347%34%10%
96
April1st to 15thDay
11%13%33%34%7%
90
16th to endDay
12%15%43%20%7%
342
May1st to 15thDay
14%10%40%25%7%
468
16th to endDay
15%7%30%32%12%1
517
June1st to 15thDay
4116%46%26%4
495
16th to endDay
5%210%42%31%7%
495
July1st to 15thDay
418%40%37%7%
475
16th to endDay
41330%47%13%
515
August1st to 15thDay
2334%45%13%
433
16th to endDay
10%5%32%35%16%
291
September1st to 15thDay
2322%47%23%
135
16th to endDay
13%2226%37%17%
135
October1st to 15thDay
210%29%42%15%
135
16th to endDay
15%5%18%28%30%2
144
November1st to 15thDay
21%5%25%31%13%2
135
16th to endDay
17%8%31%24%13%5%
135
December1st to 15thDay
19%428%31%12%3
135
16th to endDay
21%13%39%19%5%
144
January1st to 15thNight
14%8%34%32%8%
956
16th to endNight
13%9%37%31%7%
891
February1st to 15thNight
11%11%38%31%5%
704
16th to endNight
14%10%49%23%2
632
March1st to 15thNight
16%9%37%32%3
579
16th to endNight
9%13%43%29%4
576
April1st to 15thNight
9%8%52%27%2
539
16th to endNight
10%8%48%26%6%
540
May1st to 15thNight
9%8%46%29%5%
540
16th to endNight
8%238%36%13%
563
June1st to 15thNight
224%53%18%
540
16th to endNight
4115%54%20%2
540
July1st to 15thNight
410%53%28%2
510
16th to endNight
36%51%34%3
564
August1st to 15thNight
2245%43%4
539
16th to endNight
7%5%41%39%4
573
September1st to 15thNight
8%7%41%37%4
540
16th to endNight
10%18%40%35%4
537
October1st to 15thNight
7%117%42%27%2
540
16th to endNight
8%427%37%19%2
768
November1st to 15thNight
9%331%38%15%1
825
16th to endNight
12%7%29%36%12%1
975
December1st to 15thNight
15%6%30%38%8%
975
16th to endNight
16%9%33%33%7%
1040
Page generated at 2018-01-12 21:01:24. Version ac04

Copyright 2018 A. Danko


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