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 2017-03-19.

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%
15019
19%
45046
12%
14975
43%
14975
21%
29956

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%
720
16%
1980
8%
720
34%
720
19%
1397
April1st to 15thNight
28%
519
19%
1672
12%
519
39%
519
20%
1091
April16th to endNight
32%
495
21%
1514
8%
495
44%
495
21%
963
May1st to 15thNight
31%
495
17%
1485
7%
495
39%
495
18%
1031
May16th to endNight
45%
514
17%
1540
10%
513
51%
513
24%
952
June1st to 15thNight
52%
495
20%
1422
14%
495
58%
495
30%
839
June16th to endNight
53%
495
17%
1320
9%
495
59%
495
33%
806
July1st to 15thNight
53%
465
18%
1240
13%
465
57%
465
30%
788
July16th to endNight
61%
522
19%
1459
13%
489
71%
489
34%
834
August1st to 15thNight
62%
494
26%
1474
21%
491
67%
491
35%
840
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%
45754
Night
14%7%36%424447%39%
45227
Cloud CoverDay
14%7%36%5%35%45%7%36%
45763
Night
14%7%36%5%24447%39%
45232
TransparencyDay
46%5%11%21%13%2
45453
Night
45%410%22%14%2
45046
SeeingDay
15%15%21%20%16%9%
4909
Night
15%20%22%25%14%1
15021

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%24445%31%
1975
April1st to 15thDay
19%7%35%424446%38%
1954
16th to endDay
18%6%35%5%25%346%39%
2115
May1st to 15thDay
22%6%36%6%25%45%6%30%
2136
16th to endDay
11%5%26%5%37%5%6%8%35%
2223
June1st to 15thDay
11%326%5%35%6%6%8%40%
2204
16th to endDay
9%425%5%46%6%6%8%39%
2310
July1st to 15thDay
11%5%36%6%36%5%6%9%35%
2310
16th to endDay
7%425%5%48%7%7%11%35%
2291
August1st to 15thDay
7%425%6%45%6%6%10%41%
2145
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%4245%47%35%
1980
April1st to 15thNight
15%6%45%5%2345%6%40%
1672
16th to endNight
13%6%36%42445%8%40%
1514
May1st to 15thNight
18%6%35%5%25%45%7%34%
1485
16th to endNight
9%424425%6%6%10%43%
1538
June1st to 15thNight
6%4144344410%49%
1422
16th to endNight
6%224335%6%6%10%47%
1320
July1st to 15thNight
9%5%246%3445%8%47%
1320
16th to endNight
7%325%43436%11%47%
1566
August1st to 15thNight
6%32443346%11%49%
1485
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%45%5%3445%5%31%
1974
April1st to 15thDay
19%6%35%434446%37%
1954
16th to endDay
18%6%25%5%34346%39%
2115
May1st to 15thDay
21%6%26%6%345%5%6%30%
2136
16th to endDay
11%5%26%7%36%5%5%9%35%
2223
June1st to 15thDay
11%425%5%25%6%6%9%39%
2204
16th to endDay
9%425%6%47%6%6%8%39%
2310
July1st to 15thDay
12%5%36%6%35%5%5%9%34%
2310
16th to endDay
8%4345%48%7%7%11%35%
2291
August1st to 15thDay
6%425%6%45%5%7%9%41%
2145
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
17%8%35%5%25%5%47%35%
1980
April1st to 15thNight
15%6%35%424446%39%
1672
16th to endNight
14%5%26%5%25%35%8%40%
1514
May1st to 15thNight
19%6%35%5%35%36%7%34%
1484
16th to endNight
9%4235%25%6%6%10%42%
1538
June1st to 15thNight
6%4245%244411%49%
1422
16th to endNight
5%315%335%5%7%10%47%
1320
July1st to 15thNight
9%5%35%43435%7%47%
1320
16th to endNight
6%32443446%11%47%
1566
August1st to 15thNight
6%3244235%6%10%49%
1485
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
53%410%21%8%
1975
April1st to 15thDay
47%39%23%13%1
1954
16th to endDay
46%38%23%14%4
2115
May1st to 15thDay
52%6%11%17%10%1
2136
16th to endDay
44%7%12%21%12%1
2227
June1st to 15thDay
38%6%13%24%15%1
2204
16th to endDay
40%7%12%20%15%3
2310
July1st to 15thDay
44%5%10%19%17%2
2161
16th to endDay
37%9%14%23%11%2
2135
August1st to 15thDay
36%5%14%24%16%2
2132
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%412%23%9%1
1980
April1st to 15thNight
44%49%22%17%2
1672
16th to endNight
41%49%21%14%8%
1514
May1st to 15thNight
48%5%11%23%9%1
1485
16th to endNight
35%7%15%21%16%4
1540
June1st to 15thNight
31%5%12%29%18%2
1422
16th to endNight
29%8%17%20%20%3
1320
July1st to 15thNight
36%5%10%23%19%5%
1240
16th to endNight
29%5%15%31%16%2
1459
August1st to 15thNight
28%5%13%28%20%2
1474
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
21%25%28%14%9%1
238
April1st to 15thDay
19%25%20%21%10%2
210
16th to endDay
19%18%21%16%13%10%
210
May1st to 15thDay
20%19%25%19%9%6%
228
16th to endDay
18%16%18%21%13%10%
267
June1st to 15thDay
10%14%17%29%19%7%
314
16th to endDay
11%16%22%27%15%5%
420
July1st to 15thDay
14%13%19%23%18%11%
400
16th to endDay
9%11%7%24%23%23%
277
August1st to 15thDay
7%7%9%24%22%27%
253
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%24%26%23%6%
720
April1st to 15thNight
15%24%29%21%8%
519
16th to endNight
15%22%26%24%10%1
495
May1st to 15thNight
17%22%22%24%12%
495
16th to endNight
11%20%17%28%18%4
515
June1st to 15thNight
7%19%13%37%18%2
495
16th to endNight
5%18%16%33%24%1
495
July1st to 15thNight
11%13%13%30%27%3
465
16th to endNight
7%18%6%30%31%5%
522
August1st to 15thNight
8%10%11%32%32%5%
494
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 2017-03-20 08:18:33. Version ac04

Copyright 2017 A. Danko


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