Oakland(AR)
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Oakland(AR) clear sky chart from 2005-11-05 to 2017-09-24.

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
44%
15764
24%
47024
15%
15717
52%
15717
30%
28309

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
24%
900
25%
2327
8%
895
36%
895
26%
1508
January16th to endNight
24%
960
27%
2496
8%
960
36%
960
31%
1563
February1st to 15thNight
25%
880
19%
2288
5%
876
33%
876
27%
1502
February16th to endNight
19%
627
24%
1889
7%
627
34%
627
27%
1133
March1st to 15thNight
30%
540
21%
1980
14%
540
39%
540
19%
1246
March16th to endNight
31%
576
16%
2109
12%
576
39%
576
19%
1379
April1st to 15thNight
30%
539
24%
1797
11%
539
47%
539
29%
1015
April16th to endNight
36%
540
22%
1800
15%
540
49%
540
27%
1082
May1st to 15thNight
44%
540
19%
1703
15%
540
51%
540
27%
1073
May16th to endNight
52%
563
19%
1602
15%
561
58%
561
31%
1013
June1st to 15thNight
70%
540
24%
1440
20%
540
73%
540
48%
785
June16th to endNight
69%
540
26%
1440
20%
540
73%
540
44%
825
July1st to 15thNight
70%
510
17%
1501
17%
510
72%
510
33%
902
July16th to endNight
82%
564
25%
1594
28%
531
84%
531
43%
858
August1st to 15thNight
77%
539
24%
1628
28%
536
78%
536
40%
894
August16th to endNight
75%
573
23%
1910
27%
573
77%
573
35%
1056
September1st to 15thNight
67%
540
26%
1800
28%
540
70%
540
33%
1021
September16th to endNight
61%
571
30%
1903
25%
571
67%
571
34%
1056
October1st to 15thNight
55%
660
29%
1980
22%
660
60%
660
36%
1136
October16th to endNight
44%
704
31%
2112
19%
704
54%
704
36%
1198
November1st to 15thNight
42%
700
31%
2132
18%
700
55%
700
36%
1173
November16th to endNight
33%
798
25%
2418
14%
798
44%
798
27%
1484
December1st to 15thNight
31%
900
20%
2520
9%
900
41%
900
26%
1627
December16th to endNight
27%
960
22%
2655
8%
960
38%
960
23%
1780

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
12%5%25%42445%7%44%
47888
Night
12%5%24423346%49%
47220
TransparencyDay
38%6%12%23%16%3
47588
Night
34%5%11%24%19%4
47025
SeeingDay
13%6%22%27%22%7%
5813
Night
15%8%26%30%16%1
15764

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
16%5%2442433449%
1611
16th to endDay
14%7%25%323335%47%
1728
February1st to 15thDay
14%7%35%423445%44%
1575
16th to endDay
13%7%37%434245%42%
1591
March1st to 15thDay
17%7%35%313345%43%
1980
16th to endDay
19%7%345%24446%38%
2112
April1st to 15thDay
13%5%26%42435%5%45%
2151
16th to endDay
17%6%36%5%3445%6%36%
2160
May1st to 15thDay
15%5%35%5%25%45%6%39%
2246
16th to endDay
11%5%36%6%35%5%5%8%38%
2510
June1st to 15thDay
7%325%5%35%46%8%46%
2520
16th to endDay
4325%5%26%5%8%9%46%
2520
July1st to 15thDay
8%5%26%5%36%6%8%9%35%
2364
16th to endDay
5%324437%6%7%10%44%
2466
August1st to 15thDay
10%314435%5%8%9%42%
2322
16th to endDay
7%4235%35%6%6%8%45%
2292
September1st to 15thDay
12%5%245%345%6%6%44%
2160
16th to endDay
11%5%25%42445%7%47%
1900
October1st to 15thDay
13%5%14323335%53%
1650
16th to endDay
14%41331234455%
1760
November1st to 15thDay
10%5%24313345%56%
1725
16th to endDay
19%5%23313236%47%
1539
December1st to 15thDay
17%6%25%423346%43%
1440
16th to endDay
16%8%35%334345%40%
1566
January1st to 15thNight
15%6%14423345%47%
2327
16th to endNight
12%6%34423235%52%
2496
February1st to 15thNight
13%7%25%423345%46%
2278
16th to endNight
12%6%14434345%49%
1889
March1st to 15thNight
17%7%25%42335%6%42%
1980
16th to endNight
18%6%35%424346%40%
2109
April1st to 15thNight
11%5%23414347%52%
1797
16th to endNight
15%42433435%7%46%
1800
May1st to 15thNight
14%424424436%47%
1702
16th to endNight
11%32443446%9%45%
1601
June1st to 15thNight
5%21331336%11%55%
1440
16th to endNight
4223335%45%8%55%
1440
July1st to 15thNight
5%323435%5%7%9%48%
1591
16th to endNight
42134235%5%8%57%
1702
August1st to 15thNight
422342445%10%54%
1638
16th to endNight
5%31442447%9%50%
1910
September1st to 15thNight
9%41431445%8%52%
1800
16th to endNight
9%414422346%54%
1903
October1st to 15thNight
10%5%14323345%54%
1980
16th to endNight
13%41342223457%
2112
November1st to 15thNight
9%5%13322336%57%
2132
16th to endNight
16%7%23323335%48%
2418
December1st to 15thNight
18%6%24423346%44%
2520
16th to endNight
18%7%35%42333442%
2655

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
38%39%26%18%3
1612
16th to endDay
38%310%28%15%3
1728
February1st to 15thDay
42%313%24%13%2
1576
16th to endDay
44%49%24%14%3
1591
March1st to 15thDay
42%48%22%15%5%
1980
16th to endDay
48%5%12%20%12%1
2114
April1st to 15thDay
39%411%23%18%2
2151
16th to endDay
46%6%10%19%14%2
2160
May1st to 15thDay
44%7%11%20%14%1
2246
16th to endDay
43%9%13%21%10%2
2514
June1st to 15thDay
33%8%15%23%17%
2520
16th to endDay
30%8%16%26%15%2
2520
July1st to 15thDay
40%10%14%21%11%1
2225
16th to endDay
29%10%16%28%13%1
2311
August1st to 15thDay
33%9%15%24%15%1
2308
16th to endDay
33%8%16%21%14%5%
2292
September1st to 15thDay
37%7%11%21%16%6%
2160
16th to endDay
35%6%8%25%21%2
1900
October1st to 15thDay
35%49%23%21%5%
1650
16th to endDay
31%38%28%21%6%
1760
November1st to 15thDay
31%38%26%21%8%
1725
16th to endDay
39%48%22%22%2
1539
December1st to 15thDay
42%411%22%16%1
1440
16th to endDay
45%5%10%20%15%2
1566
January1st to 15thNight
38%49%23%21%2
2327
16th to endNight
36%210%28%18%3
2496
February1st to 15thNight
39%410%25%15%2
2288
16th to endNight
35%413%25%17%4
1889
March1st to 15thNight
42%6%9%19%17%4
1980
16th to endNight
45%5%10%21%14%1
2109
April1st to 15thNight
32%5%12%24%20%5%
1797
16th to endNight
36%5%12%26%15%2
1800
May1st to 15thNight
38%6%12%21%17%3
1703
16th to endNight
34%8%17%22%14%2
1603
June1st to 15thNight
22%5%16%32%21%1
1440
16th to endNight
25%6%14%27%21%4
1440
July1st to 15thNight
30%9%13%27%16%2
1501
16th to endNight
21%8%16%32%18%1
1594
August1st to 15thNight
23%8%16%31%18%2
1628
16th to endNight
26%8%17%22%18%5%
1910
September1st to 15thNight
30%7%10%26%17%8%
1800
16th to endNight
30%5%9%20%28%4
1903
October1st to 15thNight
31%410%21%25%6%
1980
16th to endNight
31%38%24%24%8%
2112
November1st to 15thNight
29%39%25%24%7%
2132
16th to endNight
38%37%23%22%3
2418
December1st to 15thNight
40%411%23%16%2
2520
16th to endNight
45%310%21%15%3
2655

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
30%17%37%12%2
90
16th to endDay
18%33%30%12%5%
96
February1st to 15thDay
21%15%46%13%21
90
16th to endDay
19%25%32%14%7%
81
March1st to 15thDay
28%22%31%15%2
90
16th to endDay
16%24%40%14%4
98
April1st to 15thDay
13%17%31%28%8%
270
16th to endDay
23%10%32%22%8%2
270
May1st to 15thDay
17%10%33%22%14%1
383
16th to endDay
13%6%34%26%15%4
517
June1st to 15thDay
9%118%34%28%8%
495
16th to endDay
6%221%35%27%7%
495
July1st to 15thDay
9%215%37%25%9%
475
16th to endDay
6%5%24%40%22%
515
August1st to 15thDay
11%9%27%38%12%
475
16th to endDay
11%7%31%36%12%
332
September1st to 15thDay
11%211%25%36%13%
315
16th to endDay
12%316%31%26%9%
174
October1st to 15thDay
8%7%34%28%17%2
90
16th to endDay
19%229%38%8%2
96
November1st to 15thDay
8%6%34%26%20%3
90
16th to endDay
37%18%22%12%8%
90
December1st to 15thDay
22%15%33%18%36%
90
16th to endDay
23%19%37%16%2
96
January1st to 15thNight
22%16%33%22%4
900
16th to endNight
16%16%39%24%3
960
February1st to 15thNight
19%14%37%26%2
880
16th to endNight
18%14%44%20%1
627
March1st to 15thNight
20%11%34%30%2
540
16th to endNight
22%8%34%28%6%
576
April1st to 15thNight
14%12%39%27%5%
539
16th to endNight
16%9%34%31%7%
540
May1st to 15thNight
15%5%30%34%12%1
540
16th to endNight
14%324%35%20%2
563
June1st to 15thNight
7%214%43%30%2
540
16th to endNight
6%15%41%32%3
540
July1st to 15thNight
8%11%40%35%4
510
16th to endNight
4434%45%9%
564
August1st to 15thNight
6%7%34%43%7%
539
16th to endNight
6%10%36%39%5%
573
September1st to 15thNight
11%112%31%37%5%
540
16th to endNight
11%416%31%31%5%
571
October1st to 15thNight
15%322%31%23%3
660
16th to endNight
15%8%27%33%14%
704
November1st to 15thNight
13%10%30%30%15%
700
16th to endNight
23%11%29%25%11%
798
December1st to 15thNight
23%10%30%28%6%
900
16th to endNight
23%14%31%26%4
960
Page generated at 2017-09-25 08:02:19. Version ac04

Copyright 2017 A. Danko


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