Ocean View Sky Shed
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Ocean View Sky Shed clear sky chart from 2005-11-06 to 2024-01-13.

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
42%
23777
14%
74608
9%
23731
48%
23731
14%
55531

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 10thNight
26%
757
15%
2564
7%
757
38%
757
11%
1901
January11th to 20thNight
28%
732
13%
2378
6%
732
36%
732
10%
1862
January21st to endNight
24%
792
17%
2574
7%
792
36%
792
13%
1919
February1st to 10thNight
26%
720
12%
2340
6%
720
36%
720
12%
1781
February11th to 20thNight
18%
700
13%
2125
5%
700
29%
700
12%
1617
February21st to endNight
26%
592
18%
1776
8%
592
38%
592
13%
1343
March1st to 10thNight
31%
720
16%
2057
7%
720
42%
720
18%
1486
March11th to 20thNight
26%
720
13%
1980
6%
720
34%
720
13%
1554
March21st to endNight
29%
792
13%
2107
6%
792
35%
792
14%
1670
April1st to 10thNight
27%
720
14%
1800
3%
720
34%
720
17%
1381
April11th to 20thNight
39%
711
20%
1775
7%
711
45%
711
21%
1319
April21st to endNight
41%
720
15%
1800
6%
720
45%
720
19%
1375
May1st to 10thNight
35%
720
11%
1800
4%
720
39%
720
16%
1424
May11th to 20thNight
49%
474
13%
1536
9%
474
53%
474
12%
1184
May21st to endNight
58%
388
13%
1551
14%
388
60%
388
12%
1128
June1st to 10thNight
60%
360
14%
1440
17%
360
62%
360
13%
1008
June11th to 20thNight
58%
360
11%
1440
9%
360
62%
360
11%
1062
June21st to endNight
65%
360
12%
1440
14%
360
68%
360
13%
1049
July1st to 10thNight
66%
350
11%
1400
14%
350
66%
350
13%
1009
July11th to 20thNight
74%
457
12%
1501
11%
457
75%
457
18%
1075
July21st to endNight
66%
591
10%
1672
7%
558
68%
558
16%
1277
August1st to 10thNight
66%
541
10%
1604
8%
538
67%
538
16%
1217
August11th to 20thNight
61%
710
12%
1774
7%
710
62%
710
17%
1403
August21st to endNight
64%
792
9%
1980
5%
792
64%
792
15%
1585
September1st to 10thNight
62%
720
18%
1800
11%
720
64%
720
20%
1374
September11th to 20thNight
60%
720
18%
1800
13%
720
61%
720
19%
1389
September21st to endNight
47%
720
13%
2022
10%
720
51%
720
14%
1601
October1st to 10thNight
53%
720
16%
2160
14%
720
57%
720
16%
1626
October11th to 20thNight
47%
720
18%
2160
14%
720
53%
720
15%
1622
October21st to endNight
43%
792
18%
2376
12%
792
51%
792
15%
1774
November1st to 10thNight
42%
740
16%
2316
11%
740
49%
740
15%
1678
November11th to 20thNight
37%
760
16%
2470
11%
760
44%
760
13%
1843
November21st to endNight
42%
760
16%
2512
12%
760
48%
760
14%
1865
December1st to 10thNight
29%
760
14%
2660
7%
760
40%
760
11%
1974
December11th to 20thNight
30%
760
16%
3169
8%
759
40%
759
10%
2253
December21st to endNight
33%
826
11%
4749
7%
817
44%
817
8%
2903

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
13%6%25%5%35%5%6%8%43%
74682
Night
14%6%25%5%3445%8%43%
75055
TransparencyDay
26%36%8%17%11%2
74394
Night
26%36%8%16%12%2
74862
SeeingDay
16%9%26%27%18%5%
14126
Night
16%8%26%31%16%2
23794

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 10thDay
15%7%25%4435%47%45%
1597
11th to 20thDay
15%7%35%5%3445%7%42%
1644
21st to endDay
15%6%35%42445%7%45%
1782
February1st to 10thDay
14%8%36%5%35%5%6%7%39%
1620
11th to 20thDay
20%6%3442345%5%45%
1721
21st to endDay
17%8%35%5%245%6%7%38%
1480
March1st to 10thDay
13%6%24423346%52%
1898
11th to 20thDay
16%6%34434447%43%
1980
21st to endDay
15%6%33425%5%6%8%41%
2247
April1st to 10thDay
13%5%24424348%51%
2160
11th to 20thDay
10%424435%5%5%7%49%
2134
21st to endDay
13%5%25%5%3446%7%45%
2160
May1st to 10thDay
14%5%25%3346%6%9%43%
2160
11th to 20thDay
15%7%25%5%245%6%8%41%
2369
21st to endDay
12%6%25%435%47%10%42%
2725
June1st to 10thDay
10%5%24436%6%8%12%41%
2520
11th to 20thDay
11%5%245%35%5%7%11%42%
2520
21st to endDay
7%4246%46%7%7%12%40%
2520
July1st to 10thDay
8%425%5%36%7%8%12%40%
2520
11th to 20thDay
7%4246%46%6%9%12%40%
2404
21st to endDay
6%4247%47%7%9%11%39%
2547
August1st to 10thDay
9%5%36%6%5%6%7%9%10%35%
2304
11th to 20thDay
10%7%26%6%46%7%7%10%35%
2126
21st to endDay
11%6%25%6%45%6%7%12%37%
2376
September1st to 10thDay
14%5%25%5%35%5%7%9%41%
2160
11th to 20thDay
13%7%26%5%3446%7%42%
2160
21st to endDay
19%7%25%5%345%48%37%
1934
October1st to 10thDay
18%5%35%42435%6%45%
1800
11th to 20thDay
14%5%26%424445%49%
1800
21st to endDay
12%5%25%6%24446%50%
1980
November1st to 10thDay
15%5%24334446%49%
1758
11th to 20thDay
14%6%245%24348%48%
1710
21st to endDay
14%4245%25%45%5%50%
1664
December1st to 10thDay
17%5%35%5%2446%7%41%
1520
11th to 20thDay
15%6%2432335%5%51%
1910
21st to endDay
16%6%35%5%3445%8%44%
2772
January1st to 10thNight
14%8%25%4245%47%45%
2564
11th to 20thNight
16%7%25%6%35%5%47%39%
2378
21st to endNight
17%6%25%434347%46%
2574
February1st to 10thNight
17%7%35%4345%5%6%41%
2340
11th to 20thNight
20%7%25%5%24447%40%
2123
21st to endNight
16%7%345%24346%46%
1776
March1st to 10thNight
13%5%25%5%2445%5%50%
2057
11th to 20thNight
17%7%345%35%46%6%40%
1980
21st to endNight
17%7%25%5%35%447%41%
2107
April1st to 10thNight
13%6%246%345%6%8%43%
1800
11th to 20thNight
12%5%245%2335%7%50%
1775
21st to endNight
15%6%24435%45%7%46%
1800
May1st to 10thNight
13%7%35%5%35%5%6%9%39%
1800
11th to 20thNight
14%5%246%35%46%11%39%
1535
21st to endNight
13%425%6%346%5%9%42%
1550
June1st to 10thNight
11%5%245%36%5%7%11%41%
1440
11th to 20thNight
8%5%36%5%45%6%7%10%41%
1440
21st to endNight
6%5%35%5%45%6%7%11%42%
1440
July1st to 10thNight
7%6%247%45%6%6%11%43%
1440
11th to 20thNight
7%425%5%36%6%8%10%44%
1551
21st to endNight
8%5%36%5%37%6%9%12%36%
1771
August1st to 10thNight
7%6%36%6%5%6%6%7%11%38%
1615
11th to 20thNight
10%7%36%7%35%6%7%9%38%
1774
21st to endNight
10%6%36%6%37%5%7%10%38%
1980
September1st to 10thNight
12%6%25%5%35%5%5%9%45%
1800
11th to 20thNight
12%7%25%6%3445%7%44%
1800
21st to endNight
18%8%35%6%4445%7%36%
2022
October1st to 10thNight
15%6%345%3445%6%47%
2160
11th to 20thNight
16%6%24423446%49%
2160
21st to endNight
14%5%24433446%49%
2376
November1st to 10thNight
15%6%25%42345%7%47%
2316
11th to 20thNight
15%5%35%42445%7%46%
2470
21st to endNight
12%5%25%435%45%7%49%
2512
December1st to 10thNight
17%7%36%6%35%446%40%
2660
11th to 20thNight
17%6%24423446%47%
3285
21st to endNight
13%6%35%5%345%6%7%44%
4884

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 10thDay
25%38%7%20%9%1
1598
11th to 20thDay
25%40%7%15%11%2
1644
21st to endDay
27%36%7%17%12%2
1782
February1st to 10thDay
29%35%7%17%10%2
1620
11th to 20thDay
28%35%5%15%15%3
1730
21st to endDay
30%35%8%13%11%4
1480
March1st to 10thDay
21%35%7%20%14%3
1898
11th to 20thDay
27%35%7%15%12%3
1980
21st to endDay
29%36%9%15%10%1
2247
April1st to 10thDay
22%35%8%17%14%5%
2160
11th to 20thDay
23%35%7%16%15%4
2134
21st to endDay
25%35%8%16%13%3
2160
May1st to 10thDay
27%36%9%16%10%1
2160
11th to 20thDay
30%37%8%15%7%2
2373
21st to endDay
25%37%11%18%9%
2725
June1st to 10thDay
22%37%12%20%9%1
2520
11th to 20thDay
27%36%10%17%8%1
2520
21st to endDay
25%38%11%17%9%1
2520
July1st to 10thDay
23%39%12%17%9%1
2450
11th to 20thDay
23%39%14%16%8%1
2331
21st to endDay
23%39%15%15%7%
2405
August1st to 10thDay
26%38%11%18%6%1
2291
11th to 20thDay
29%37%9%16%8%1
2126
21st to endDay
28%37%12%13%8%2
2376
September1st to 10thDay
25%38%9%12%13%3
2160
11th to 20thDay
27%35%5%18%14%1
2160
21st to endDay
32%36%5%12%13%2
1934
October1st to 10thDay
27%36%316%16%3
1800
11th to 20thDay
27%35%418%13%3
1800
21st to endDay
26%36%416%15%3
1980
November1st to 10thDay
21%40%5%18%14%2
1758
11th to 20thDay
23%39%9%16%12%2
1710
21st to endDay
24%38%6%17%13%2
1664
December1st to 10thDay
24%39%10%15%11%1
1520
11th to 20thDay
27%31%5%20%12%5%
1906
21st to endDay
29%24%9%24%13%1
2772
January1st to 10thNight
24%39%7%17%11%2
2564
11th to 20thNight
28%41%7%13%10%1
2378
21st to endNight
27%36%5%17%12%2
2574
February1st to 10thNight
30%36%416%12%3
2340
11th to 20thNight
29%35%5%16%12%3
2125
21st to endNight
28%36%6%14%13%4
1776
March1st to 10thNight
22%35%7%17%16%2
2057
11th to 20thNight
31%36%8%13%10%2
1980
21st to endNight
30%36%6%15%10%2
2107
April1st to 10thNight
26%36%8%13%14%3
1800
11th to 20thNight
22%35%7%17%15%5%
1775
21st to endNight
25%36%6%17%13%3
1800
May1st to 10thNight
28%36%9%16%9%2
1800
11th to 20thNight
30%37%9%13%9%2
1536
21st to endNight
25%38%11%17%9%
1551
June1st to 10thNight
24%37%10%20%10%
1440
11th to 20thNight
27%38%13%14%8%1
1440
21st to endNight
24%40%11%16%8%2
1440
July1st to 10thNight
24%39%12%16%7%2
1400
11th to 20thNight
20%39%15%16%10%1
1501
21st to endNight
24%40%14%16%6%
1672
August1st to 10thNight
25%38%15%17%5%
1604
11th to 20thNight
29%36%11%15%8%
1774
21st to endNight
30%38%11%15%6%1
1980
September1st to 10thNight
24%37%9%15%13%3
1800
11th to 20thNight
26%36%6%16%15%1
1800
21st to endNight
32%36%5%13%13%2
2022
October1st to 10thNight
26%37%314%17%2
2160
11th to 20thNight
27%35%5%17%13%3
2160
21st to endNight
25%37%416%14%4
2376
November1st to 10thNight
21%40%5%16%16%2
2316
11th to 20thNight
25%39%7%14%13%3
2470
21st to endNight
24%39%6%16%13%2
2512
December1st to 10thNight
25%38%7%15%12%2
2660
11th to 20thNight
29%32%7%13%16%3
3288
21st to endNight
28%25%11%21%14%1
4884

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 10thDay
20%18%40%17%5%
218
11th to 20thDay
20%19%39%20%2
248
21st to endDay
20%15%39%21%41
264
February1st to 10thDay
19%15%44%16%6%
240
11th to 20thDay
27%19%36%15%3
389
21st to endDay
21%16%41%18%21
346
March1st to 10thDay
13%19%42%21%5%
420
11th to 20thDay
20%18%36%20%5%1
420
21st to endDay
15%16%37%26%6%
462
April1st to 10thDay
16%17%37%22%7%1
420
11th to 20thDay
11%13%34%28%11%3
412
21st to endDay
14%12%34%30%10%1
420
May1st to 10thDay
17%11%34%26%11%2
423
11th to 20thDay
19%5%27%30%17%2
447
21st to endDay
18%420%29%22%7%
485
June1st to 10thDay
13%318%33%27%6%
450
11th to 20thDay
13%6%20%29%24%9%
450
21st to endDay
9%416%40%26%6%
450
July1st to 10thDay
9%19%35%37%10%
445
11th to 20thDay
8%28%32%39%11%
444
21st to endDay
8%115%34%33%10%
488
August1st to 10thDay
12%213%35%30%9%
446
11th to 20thDay
13%211%31%30%13%
439
21st to endDay
12%214%27%33%12%
495
September1st to 10thDay
16%314%28%25%14%
450
11th to 20thDay
14%317%30%25%10%
450
21st to endDay
21%7%21%27%20%4
450
October1st to 10thDay
21%419%25%23%7%
450
11th to 20thDay
15%9%25%28%20%3
450
21st to endDay
16%8%32%27%12%4
495
November1st to 10thDay
18%9%27%27%14%5%
408
11th to 20thDay
16%15%32%23%12%2
370
21st to endDay
17%15%27%23%16%2
324
December1st to 10thDay
23%10%43%18%5%2
180
11th to 20thDay
16%15%36%23%9%
180
21st to endDay
22%14%31%20%12%1
198
January1st to 10thNight
17%17%34%25%6%
760
11th to 20thNight
20%14%31%27%7%
732
21st to endNight
20%13%38%26%2
792
February1st to 10thNight
21%10%41%24%4
720
11th to 20thNight
23%17%38%18%3
703
21st to endNight
20%14%36%26%4
592
March1st to 10thNight
17%11%38%28%6%
720
11th to 20thNight
21%11%37%23%6%1
720
21st to endNight
19%11%36%28%6%
792
April1st to 10thNight
18%12%38%26%7%
720
11th to 20thNight
13%10%34%32%11%1
711
21st to endNight
15%8%31%37%9%1
720
May1st to 10thNight
15%9%34%32%9%1
720
11th to 20thNight
16%325%40%15%1
474
21st to endNight
15%316%38%24%4
389
June1st to 10thNight
13%317%41%23%4
360
11th to 20thNight
11%218%41%25%4
360
21st to endNight
8%214%44%29%2
360
July1st to 10thNight
7%113%42%34%3
350
11th to 20thNight
7%16%41%41%4
457
21st to endNight
9%312%41%32%4
591
August1st to 10thNight
9%110%42%32%5%
541
11th to 20thNight
13%211%36%32%6%
710
21st to endNight
13%211%30%37%8%
792
September1st to 10thNight
15%211%35%30%8%
720
11th to 20thNight
15%212%34%31%6%
720
21st to endNight
22%5%16%33%23%2
720
October1st to 10thNight
18%5%16%29%26%6%
720
11th to 20thNight
18%8%22%31%18%2
720
21st to endNight
16%9%27%28%17%3
792
November1st to 10thNight
19%8%24%29%16%4
740
11th to 20thNight
16%11%31%27%13%1
760
21st to endNight
14%12%29%31%13%1
760
December1st to 10thNight
21%13%32%25%9%1
760
11th to 20thNight
19%10%36%28%7%
760
21st to endNight
18%12%30%33%7%
836
Page generated at 2024-01-10 19:35:22. Version ac07

Copyright 2024 Attilla Danko


Ocean View Sky Shed Clear Sky Chart |Charts Home