Lake Casa Blanca International State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake Casa Blanca International State Park clear sky chart from 2005-11-05 to 2017-09-22.

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
55%
15256
27%
47061
19%
15215
62%
15215
38%
25908

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
49%
867
24%
2299
13%
867
54%
867
32%
1478
January16th to endNight
46%
768
28%
2304
17%
768
54%
768
32%
1354
February1st to 15thNight
44%
704
30%
2112
15%
700
57%
700
37%
1172
February16th to endNight
35%
632
28%
1894
11%
632
48%
632
40%
1011
March1st to 15thNight
40%
598
29%
2038
16%
598
54%
598
33%
1106
March16th to endNight
30%
576
25%
2112
13%
576
47%
576
33%
1108
April1st to 15thNight
31%
539
27%
1977
12%
539
51%
539
36%
993
April16th to endNight
31%
540
27%
1805
14%
540
49%
540
32%
1018
May1st to 15thNight
32%
539
23%
1640
12%
539
45%
539
32%
969
May16th to endNight
43%
562
28%
1683
17%
561
59%
561
41%
918
June1st to 15thNight
68%
540
24%
1620
24%
540
74%
540
58%
747
June16th to endNight
66%
540
22%
1620
21%
540
72%
540
41%
881
July1st to 15thNight
71%
510
19%
1530
20%
510
74%
510
41%
846
July16th to endNight
81%
564
27%
1668
31%
531
85%
531
47%
831
August1st to 15thNight
83%
539
30%
1789
33%
536
86%
536
55%
789
August16th to endNight
78%
573
24%
1943
27%
573
81%
573
36%
1058
September1st to 15thNight
73%
540
19%
1980
22%
540
75%
540
28%
1150
September16th to endNight
74%
513
22%
1891
24%
513
76%
513
30%
1058
October1st to 15thNight
72%
495
33%
1815
33%
495
75%
495
41%
868
October16th to endNight
68%
630
36%
2038
28%
630
73%
630
48%
971
November1st to 15thNight
61%
727
31%
2127
20%
727
65%
727
40%
1178
November16th to endNight
59%
900
32%
2340
18%
900
65%
900
44%
1344
December1st to 15thNight
50%
900
28%
2340
17%
900
53%
900
33%
1507
December16th to endNight
49%
960
26%
2496
14%
960
53%
960
36%
1553

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%424424447%51%
47804
Night
9%313323347%56%
47266
TransparencyDay
32%5%11%20%19%10%
47512
Night
27%5%13%22%18%11%
47064
SeeingDay
8%218%39%25%6%
5160
Night
11%325%44%14%1
15263

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
18%6%35%223336%44%
1650
16th to endDay
13%5%1332345%6%49%
1920
February1st to 15thDay
12%5%25%42333452%
1750
16th to endDay
12%5%12322235%57%
1580
March1st to 15thDay
13%42332345%6%50%
1920
16th to endDay
10%423423347%53%
2110
April1st to 15thDay
10%314323446%55%
1971
16th to endDay
9%42342345%7%51%
2151
May1st to 15thDay
10%4245%2446%7%47%
2307
16th to endDay
9%4245%25%46%7%48%
2430
June1st to 15thDay
2112435%349%61%
2340
16th to endDay
5%2235%36%45%9%51%
2340
July1st to 15thDay
7%425%5%35%45%7%47%
2340
16th to endDay
42235%3446%9%51%
2382
August1st to 15thDay
2113314448%65%
2160
16th to endDay
7%315%5%36%5%5%6%50%
2259
September1st to 15thDay
10%5%26%6%45%5%47%39%
1980
16th to endDay
9%425%6%45%5%7%8%41%
1881
October1st to 15thDay
6%323323346%58%
1815
16th to endDay
7%313323345%61%
1822
November1st to 15thDay
9%6%26%412335%51%
1728
16th to endDay
12%5%13314235%56%
1620
December1st to 15thDay
22%6%23324345%40%
1620
16th to endDay
16%5%24423335%48%
1728
January1st to 15thNight
18%423323345%48%
2299
16th to endNight
15%413323335%51%
2304
February1st to 15thNight
11%414313336%56%
2102
16th to endNight
11%413312445%58%
1894
March1st to 15thNight
10%424324246%56%
2038
16th to endNight
8%31342445%8%53%
2112
April1st to 15thNight
8%213315%35%9%55%
1977
16th to endNight
10%413324347%52%
1805
May1st to 15thNight
7%4244345%7%7%49%
1640
16th to endNight
6%21342346%10%53%
1683
June1st to 15thNight
112212349%68%
1620
16th to endNight
31133245%6%10%56%
1620
July1st to 15thNight
5%3133245%6%9%54%
1620
16th to endNight
321321345%8%61%
1782
August1st to 15thNight
221222347%70%
1800
16th to endNight
331443445%8%55%
1943
September1st to 15thNight
7%5%245%245%6%8%47%
1980
16th to endNight
9%41342347%10%47%
1891
October1st to 15thNight
5%213312345%64%
1815
16th to endNight
6%31221222469%
2038
November1st to 15thNight
10%323213346%58%
2127
16th to endNight
9%412313335%61%
2340
December1st to 15thNight
19%5%22312236%49%
2340
16th to endNight
16%423313235%53%
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
42%36%16%17%13%
1651
16th to endDay
34%48%18%19%14%
1920
February1st to 15thDay
36%36%13%19%20%
1751
16th to endDay
31%36%19%26%14%
1580
March1st to 15thDay
34%49%18%16%16%
1920
16th to endDay
29%5%13%16%18%16%
2112
April1st to 15thDay
29%411%17%21%15%
1971
16th to endDay
31%5%9%17%19%15%
2151
May1st to 15thDay
35%5%10%21%18%8%
2307
16th to endDay
33%6%10%20%22%6%
2434
June1st to 15thDay
20%6%11%25%27%8%
2340
16th to endDay
29%7%14%23%20%4
2340
July1st to 15thDay
34%6%13%23%18%2
2201
16th to endDay
25%8%16%33%14%1
2234
August1st to 15thDay
17%6%16%35%22%
2147
16th to endDay
33%8%15%26%13%2
2259
September1st to 15thDay
43%7%13%18%13%3
1980
16th to endDay
37%8%14%16%14%7%
1881
October1st to 15thDay
27%49%18%29%9%
1815
16th to endDay
24%47%19%25%18%
1822
November1st to 15thDay
35%49%18%21%11%
1728
16th to endDay
31%47%17%18%21%
1620
December1st to 15thDay
46%5%8%13%14%12%
1620
16th to endDay
39%47%16%19%13%
1728
January1st to 15thNight
38%47%14%18%16%
2299
16th to endNight
34%48%16%21%15%
2304
February1st to 15thNight
29%37%17%18%23%
2112
16th to endNight
27%39%19%23%15%
1894
March1st to 15thNight
30%411%18%18%16%
2038
16th to endNight
28%5%13%17%18%15%
2112
April1st to 15thNight
25%5%13%20%20%14%
1977
16th to endNight
31%5%11%20%18%13%
1805
May1st to 15thNight
31%7%13%21%14%11%
1641
16th to endNight
25%6%15%27%20%4
1685
June1st to 15thNight
12%6%18%28%27%6%
1620
16th to endNight
22%9%16%27%21%2
1620
July1st to 15thNight
23%8%23%28%14%1
1530
16th to endNight
17%8%25%35%11%1
1668
August1st to 15thNight
14%5%20%43%15%
1789
16th to endNight
25%9%21%31%9%2
1943
September1st to 15thNight
32%9%20%21%13%3
1980
16th to endNight
29%9%18%22%13%6%
1891
October1st to 15thNight
22%5%12%24%23%12%
1815
16th to endNight
21%27%20%26%21%
2038
November1st to 15thNight
27%49%19%26%11%
2127
16th to endNight
26%49%19%17%23%
2340
December1st to 15thNight
38%49%17%17%12%
2340
16th to endNight
34%37%17%19%16%
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
20%223%38%15%
90
16th to endDay
14%7%34%23%19%
96
February1st to 15thDay
7%335%28%20%4
90
16th to endDay
8%7%34%37%11%1
81
March1st to 15thDay
22%227%26%16%4
90
16th to endDay
7%134%48%8%
96
April1st to 15thDay
10%35%43%11%
90
16th to endDay
6%7%40%32%12%
261
May1st to 15thDay
12%342%34%7%
444
16th to endDay
11%427%47%8%
517
June1st to 15thDay
18%58%27%3
495
16th to endDay
410%47%30%6%
495
July1st to 15thDay
7%11%43%33%3
475
16th to endDay
3342%41%7%
431
August1st to 15thDay
4239%39%14%
315
16th to endDay
6%1443%27%16%
299
September1st to 15thDay
8%314%48%25%
135
16th to endDay
312%48%34%
108
October1st to 15thDay
6%414%36%37%
90
16th to endDay
8%6%11%26%37%10%
96
November1st to 15thDay
15%423%28%23%4
90
16th to endDay
12%11%22%27%20%6%
90
December1st to 15thDay
31%318%16%16%13%
90
16th to endDay
19%5%25%31%14%4
96
January1st to 15thNight
20%221%42%12%
872
16th to endNight
16%5%24%45%7%
768
February1st to 15thNight
14%5%31%39%8%
704
16th to endNight
14%440%35%4
632
March1st to 15thNight
14%7%36%36%5%
598
16th to endNight
9%7%50%31%1
576
April1st to 15thNight
8%453%31%1
539
16th to endNight
10%5%51%29%3
540
May1st to 15thNight
7%6%49%33%2
540
16th to endNight
7%242%41%5%
563
June1st to 15thNight
225%63%8%
540
16th to endNight
424%56%12%
540
July1st to 15thNight
7%14%63%13%
510
16th to endNight
319%67%18%
564
August1st to 15thNight
38%64%22%1
539
16th to endNight
45%61%24%2
573
September1st to 15thNight
9%6%47%31%5%
540
16th to endNight
9%8%42%32%6%
513
October1st to 15thNight
6%14%48%28%1
495
16th to endNight
8%216%45%26%
630
November1st to 15thNight
10%221%43%21%1
727
16th to endNight
10%321%42%20%2
900
December1st to 15thNight
21%320%40%13%1
900
16th to endNight
18%323%39%14%
960
Page generated at 2017-09-23 05:43:35. Version ac04

Copyright 2017 A. Danko


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