Cincinnati
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cincinnati clear sky chart from 2005-11-05 to 2017-08-12.

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
36%
15462
19%
46341
12%
15418
44%
15418
21%
30748

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
17%
873
13%
2479
6%
868
24%
868
12%
1941
January16th to endNight
19%
768
14%
2496
7%
768
28%
768
12%
1846
February1st to 15thNight
20%
703
12%
2160
6%
701
26%
701
13%
1552
February16th to endNight
19%
631
14%
1893
7%
631
26%
631
14%
1377
March1st to 15thNight
22%
720
15%
2097
8%
720
29%
720
16%
1487
March16th to endNight
27%
768
16%
2112
8%
768
35%
768
19%
1490
April1st to 15thNight
28%
566
18%
1824
11%
566
39%
566
20%
1193
April16th to endNight
34%
540
21%
1651
8%
540
45%
540
22%
1048
May1st to 15thNight
30%
540
16%
1620
7%
540
38%
540
18%
1123
May16th to endNight
45%
562
18%
1684
10%
561
51%
561
24%
1048
June1st to 15thNight
54%
540
19%
1551
14%
540
59%
540
32%
893
June16th to endNight
53%
540
18%
1440
10%
540
59%
540
33%
878
July1st to 15thNight
53%
510
17%
1360
12%
510
57%
510
31%
865
July16th to endNight
62%
564
21%
1584
15%
531
71%
531
35%
892
August1st to 15thNight
63%
527
25%
1575
20%
524
67%
524
35%
903
August16th to endNight
70%
525
24%
1690
21%
525
75%
525
38%
892
September1st to 15thNight
62%
602
30%
1757
25%
602
66%
602
37%
992
September16th to endNight
53%
657
27%
1815
19%
657
58%
657
31%
1136
October1st to 15thNight
51%
660
29%
1848
23%
660
57%
660
33%
1096
October16th to endNight
36%
704
22%
2199
17%
704
45%
704
23%
1412
November1st to 15thNight
38%
700
26%
2276
19%
700
49%
700
26%
1336
November16th to endNight
26%
720
18%
2340
10%
720
35%
720
16%
1599
December1st to 15thNight
21%
720
11%
2340
7%
720
26%
720
11%
1769
December16th to endNight
16%
822
12%
2550
5%
822
24%
822
10%
1980

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
14%7%36%5%35%45%7%36%
47612
Night
14%7%36%424447%39%
46522
Cloud CoverDay
14%7%36%5%35%45%7%36%
47621
Night
14%7%36%5%2445%7%39%
46527
TransparencyDay
46%5%11%21%13%2
47311
Night
44%410%22%14%2
46341
SeeingDay
15%15%22%21%16%9%
5520
Night
15%20%22%25%14%1
15464

By Month

Percentage Cloud Cover NE (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
19%12%6%9%5%24445%25%
1453
16th to endDay
14%14%6%9%5%34346%27%
1728
February1st to 15thDay
16%12%48%5%25%346%30%
1700
16th to endDay
16%12%5%9%6%2443430%
1580
March1st to 15thDay
22%10%25%5%24446%31%
1853
16th to endDay
19%9%45%5%25%45%5%31%
2112
April1st to 15thDay
18%7%35%424446%38%
2133
16th to endDay
17%6%36%5%25%347%38%
2307
May1st to 15thDay
22%6%35%6%35%45%6%31%
2331
16th to endDay
12%6%25%5%37%5%6%8%35%
2431
June1st to 15thDay
11%326%5%346%6%8%41%
2405
16th to endDay
9%425%5%46%6%5%8%41%
2520
July1st to 15thDay
11%5%36%6%35%5%6%8%35%
2520
16th to endDay
7%425%5%47%7%7%11%37%
2474
August1st to 15thDay
7%425%6%45%6%6%10%41%
2288
16th to endDay
7%4245%45%5%7%10%42%
2157
September1st to 15thDay
10%5%345%3445%7%44%
1861
16th to endDay
14%425%424436%46%
1815
October1st to 15thDay
11%5%15%5%2435%7%45%
1782
16th to endDay
18%7%24423346%41%
1672
November1st to 15thDay
8%6%36%325%446%48%
1582
16th to endDay
17%10%36%5%23346%35%
1620
December1st to 15thDay
25%11%5%8%5%3334425%
1620
16th to endDay
20%14%5%7%5%33345%24%
1668
January1st to 15thNight
19%11%5%10%7%4443426%
2479
16th to endNight
17%13%5%7%5%25%335%29%
2496
February1st to 15thNight
20%10%48%424345%31%
2158
16th to endNight
17%12%46%5%3445%6%28%
1893
March1st to 15thNight
17%9%35%6%34446%33%
2084
16th to endNight
17%8%35%5%245%47%35%
2112
April1st to 15thNight
15%6%45%5%2345%6%39%
1824
16th to endNight
13%5%36%42445%8%40%
1651
May1st to 15thNight
18%6%35%425%45%6%35%
1620
16th to endNight
10%5%24425%6%6%10%42%
1682
June1st to 15thNight
6%4144244410%51%
1551
16th to endNight
6%224335%6%6%10%47%
1440
July1st to 15thNight
9%5%245%2435%9%46%
1440
16th to endNight
6%32443436%11%49%
1691
August1st to 15thNight
6%3244335%6%11%48%
1586
16th to endNight
5%3144235%5%11%54%
1690
September1st to 15thNight
10%41332335%7%53%
1757
16th to endNight
13%425%424335%49%
1815
October1st to 15thNight
10%314424447%50%
1848
16th to endNight
17%6%35%324345%43%
2199
November1st to 15thNight
13%5%2432345%6%47%
2276
16th to endNight
19%8%36%434445%34%
2340
December1st to 15thNight
22%11%5%8%42434427%
2340
16th to endNight
23%13%5%7%5%23345%24%
2550

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
19%11%5%9%5%34435%25%
1453
16th to endDay
14%13%6%9%6%36%246%27%
1728
February1st to 15thDay
16%12%5%8%5%34446%30%
1700
16th to endDay
16%12%5%10%5%25%345%29%
1580
March1st to 15thDay
23%9%25%5%33346%31%
1863
16th to endDay
19%9%46%6%3445%6%31%
2111
April1st to 15thDay
18%6%35%434446%37%
2133
16th to endDay
17%6%25%5%34447%38%
2307
May1st to 15thDay
22%6%26%5%345%5%6%30%
2331
16th to endDay
11%5%26%6%36%5%6%9%35%
2431
June1st to 15thDay
11%325%5%25%6%6%9%41%
2405
16th to endDay
9%425%6%46%5%5%8%40%
2520
July1st to 15thDay
11%5%36%6%45%5%5%9%35%
2520
16th to endDay
8%424447%7%7%10%36%
2474
August1st to 15thDay
7%425%6%45%5%7%9%41%
2288
16th to endDay
7%415%5%35%5%7%9%42%
2157
September1st to 15thDay
11%425%5%445%5%6%44%
1861
16th to endDay
14%5%245%23446%46%
1815
October1st to 15thDay
11%5%25%5%2445%6%45%
1782
16th to endDay
18%6%25%5%23346%41%
1672
November1st to 15thDay
9%6%35%424336%48%
1582
16th to endDay
16%10%37%433346%36%
1620
December1st to 15thDay
25%10%5%7%6%23345%25%
1620
16th to endDay
20%13%6%6%5%34435%25%
1668
January1st to 15thNight
18%11%5%10%7%3433425%
2479
16th to endNight
17%13%5%8%5%3443429%
2496
February1st to 15thNight
19%10%48%434335%31%
2151
16th to endNight
17%12%47%5%245%5%6%28%
1893
March1st to 15thNight
17%9%35%6%3445%5%33%
2097
16th to endNight
16%8%35%5%245%46%35%
2112
April1st to 15thNight
14%7%35%42445%7%39%
1824
16th to endNight
14%5%26%5%25%35%8%40%
1651
May1st to 15thNight
18%6%35%5%3436%7%34%
1619
16th to endNight
9%4235%246%6%10%42%
1682
June1st to 15thNight
5%4245%234411%50%
1551
16th to endNight
5%315%435%5%7%10%47%
1440
July1st to 15thNight
9%5%3443435%8%46%
1440
16th to endNight
6%32443446%10%49%
1691
August1st to 15thNight
6%3244245%7%10%48%
1586
16th to endNight
5%22332446%9%55%
1690
September1st to 15thNight
9%41232345%7%54%
1757
16th to endNight
13%435%5%2333450%
1815
October1st to 15thNight
9%31442445%7%50%
1848
16th to endNight
17%6%35%324345%43%
2199
November1st to 15thNight
13%42442445%6%47%
2276
16th to endNight
19%9%36%5%24445%34%
2340
December1st to 15thNight
22%11%5%8%424345%26%
2340
16th to endNight
23%12%5%7%5%23445%24%
2550

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
59%410%14%10%
1454
16th to endDay
58%313%18%5%
1728
February1st to 15thDay
55%411%18%9%
1702
16th to endDay
56%310%21%7%
1580
March1st to 15thDay
54%412%20%7%
1863
16th to endDay
54%411%20%8%
2112
April1st to 15thDay
46%410%23%13%1
2133
16th to endDay
45%39%22%14%4
2307
May1st to 15thDay
51%6%11%17%10%1
2331
16th to endDay
44%7%12%21%12%1
2435
June1st to 15thDay
37%6%13%23%17%1
2405
16th to endDay
38%7%12%21%17%3
2520
July1st to 15thDay
44%5%11%18%17%2
2371
16th to endDay
36%9%13%23%13%2
2318
August1st to 15thDay
36%5%14%23%16%2
2275
16th to endDay
34%7%12%24%16%5%
2157
September1st to 15thDay
37%411%19%20%5%
1861
16th to endDay
39%47%21%25%1
1815
October1st to 15thDay
37%5%8%25%19%3
1782
16th to endDay
44%310%25%15%1
1672
November1st to 15thDay
37%47%25%20%4
1582
16th to endDay
50%38%22%14%
1620
December1st to 15thDay
62%39%15%8%
1620
16th to endDay
62%410%16%5%
1668
January1st to 15thNight
62%36%17%9%
2479
16th to endNight
58%49%20%6%1
2496
February1st to 15thNight
55%312%20%7%1
2160
16th to endNight
54%412%19%8%
1893
March1st to 15thNight
51%49%21%11%1
2097
16th to endNight
48%5%13%22%8%1
2112
April1st to 15thNight
44%49%22%16%2
1824
16th to endNight
41%410%20%15%7%
1651
May1st to 15thNight
48%5%11%22%9%1
1620
16th to endNight
35%7%14%21%16%4
1684
June1st to 15thNight
29%5%13%29%19%2
1551
16th to endNight
29%8%17%20%20%4
1440
July1st to 15thNight
36%5%11%23%18%5%
1360
16th to endNight
28%5%14%31%17%2
1584
August1st to 15thNight
29%6%14%28%19%2
1575
16th to endNight
25%5%13%28%21%5%
1690
September1st to 15thNight
28%5%11%24%24%6%
1757
16th to endNight
37%35%22%27%2
1815
October1st to 15thNight
33%38%28%21%4
1848
16th to endNight
44%37%26%15%2
2199
November1st to 15thNight
36%310%20%23%4
2276
16th to endNight
51%39%20%13%1
2340
December1st to 15thNight
60%310%16%8%
2340
16th to endNight
62%49%15%7%
2550

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
32%17%36%6%42
90
16th to endDay
26%29%33%9%2
96
February1st to 15thDay
23%32%28%13%2
90
16th to endDay
18%20%45%13%1
81
March1st to 15thDay
25%20%32%18%1
153
16th to endDay
19%23%31%15%8%1
288
April1st to 15thDay
18%23%23%20%11%2
270
16th to endDay
17%19%25%17%12%8%
270
May1st to 15thDay
22%19%25%18%9%5%
288
16th to endDay
19%15%22%20%12%9%
331
June1st to 15thDay
9%12%17%30%22%7%
380
16th to endDay
12%16%24%26%14%5%
495
July1st to 15thDay
13%11%20%26%17%10%
475
16th to endDay
9%9%9%25%23%22%
334
August1st to 15thDay
10%7%10%23%23%24%
297
16th to endDay
7%8%8%22%30%23%
268
September1st to 15thDay
7%7%14%16%37%16%
255
16th to endDay
18%8%14%15%29%13%
254
October1st to 15thDay
10%10%23%25%21%8%
255
16th to endDay
14%9%35%28%11%
184
November1st to 15thDay
10%13%24%23%18%10%
90
16th to endDay
24%16%37%16%4
90
December1st to 15thDay
22%20%35%13%8%
90
16th to endDay
30%21%37%10%
96
January1st to 15thNight
17%27%30%19%5%
873
16th to endNight
21%25%27%22%2
768
February1st to 15thNight
22%26%26%22%1
704
16th to endNight
21%25%26%23%1
631
March1st to 15thNight
19%23%29%21%5%
720
16th to endNight
17%23%27%23%7%
768
April1st to 15thNight
15%23%29%22%9%
566
16th to endNight
15%21%26%26%10%1
540
May1st to 15thNight
18%21%24%23%11%
540
16th to endNight
11%19%18%28%18%3
563
June1st to 15thNight
7%17%14%37%20%2
540
16th to endNight
5%16%18%33%23%1
540
July1st to 15thNight
11%12%13%31%27%3
510
16th to endNight
7%17%6%29%32%5%
564
August1st to 15thNight
7%9%11%32%33%4
527
16th to endNight
49%10%30%37%7%
525
September1st to 15thNight
9%11%11%27%34%5%
602
16th to endNight
12%11%13%27%29%5%
657
October1st to 15thNight
10%12%21%28%22%4
660
16th to endNight
16%16%27%26%12%1
704
November1st to 15thNight
13%21%23%22%17%1
700
16th to endNight
21%23%24%20%8%
720
December1st to 15thNight
24%22%24%19%7%
720
16th to endNight
25%27%25%17%3
822
Page generated at 2017-08-13 14:16:17. Version ac04

Copyright 2017 A. Danko


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