Morehead State University
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Morehead State University clear sky chart from 2005-11-06 to 2024-01-14.

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
40%
23835
19%
74581
13%
23783
46%
23783
22%
49872

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
18%
760
14%
2459
6%
757
28%
757
12%
1827
January11th to 20thNight
17%
735
14%
2386
7%
735
25%
735
11%
1826
January21st to endNight
17%
792
15%
2574
7%
792
27%
792
14%
1850
February1st to 10thNight
19%
720
12%
2277
5%
720
27%
720
13%
1710
February11th to 20thNight
15%
703
14%
2099
5%
700
24%
700
13%
1548
February21st to endNight
12%
592
14%
1776
4%
592
22%
592
12%
1362
March1st to 10thNight
22%
720
20%
2093
9%
720
32%
720
18%
1433
March11th to 20thNight
23%
720
17%
1980
8%
720
30%
720
18%
1412
March21st to endNight
29%
792
15%
2178
8%
792
35%
792
19%
1551
April1st to 10thNight
32%
684
20%
1944
10%
684
41%
684
26%
1269
April11th to 20thNight
37%
533
23%
1692
14%
533
46%
533
25%
1055
April21st to endNight
32%
540
19%
1620
8%
540
42%
540
23%
1107
May1st to 10thNight
36%
540
16%
1620
9%
540
42%
540
21%
1112
May11th to 20thNight
45%
531
16%
1592
10%
531
49%
531
22%
1104
May21st to endNight
57%
583
18%
1745
13%
582
61%
582
29%
1097
June1st to 10thNight
61%
540
18%
1620
15%
540
64%
540
33%
976
June11th to 20thNight
63%
540
18%
1620
16%
540
65%
540
33%
977
June21st to endNight
60%
540
18%
1620
16%
540
62%
540
31%
1001
July1st to 10thNight
59%
525
14%
1575
13%
525
60%
525
28%
1020
July11th to 20thNight
71%
522
18%
1566
16%
522
73%
522
34%
935
July21st to endNight
67%
591
20%
1672
18%
558
69%
558
30%
1055
August1st to 10thNight
68%
537
21%
1600
20%
534
69%
534
33%
965
August11th to 20thNight
67%
534
21%
1598
20%
534
68%
534
30%
1010
August21st to endNight
68%
594
24%
1903
24%
594
70%
594
34%
1095
September1st to 10thNight
65%
690
22%
1950
18%
690
67%
690
33%
1200
September11th to 20thNight
62%
720
27%
1980
19%
720
66%
720
36%
1200
September21st to endNight
52%
720
26%
1980
18%
720
58%
720
31%
1262
October1st to 10thNight
58%
720
27%
1988
23%
720
62%
720
37%
1177
October11th to 20thNight
42%
720
25%
2160
19%
720
50%
720
29%
1329
October21st to endNight
35%
792
25%
2414
18%
792
46%
792
24%
1583
November1st to 10thNight
45%
740
26%
2406
22%
740
55%
740
29%
1410
November11th to 20thNight
32%
760
24%
2470
15%
760
45%
760
22%
1555
November21st to endNight
35%
760
21%
2470
15%
760
44%
760
22%
1621
December1st to 10thNight
22%
760
14%
2470
7%
760
31%
760
13%
1803
December11th to 20thNight
26%
759
17%
2988
11%
759
35%
759
13%
2079
December21st to endNight
21%
826
9%
4496
7%
817
30%
817
7%
3356

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
15%8%36%5%35%5%5%7%36%
74894
Night
15%9%36%5%3445%7%38%
74878
TransparencyDay
47%6%11%21%14%2
74617
Night
45%6%11%21%15%3
74674
SeeingDay
22%12%25%21%13%6%
13715
Night
20%10%24%27%16%2
23847

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
16%13%7%9%7%345%45%28%
1706
11th to 20thDay
20%14%6%11%6%3444423%
1647
21st to endDay
18%15%6%7%5%33346%29%
1782
February1st to 10thDay
20%12%5%10%6%33436%28%
1682
11th to 20thDay
20%10%5%9%5%35%45%5%29%
1748
21st to endDay
20%12%47%5%35%446%30%
1480
March1st to 10thDay
20%11%35%325%45%5%37%
1866
11th to 20thDay
20%9%48%6%3445%6%32%
1980
21st to endDay
20%10%46%5%35%45%6%31%
2178
April1st to 10thDay
13%9%47%6%4435%6%38%
2031
11th to 20thDay
18%7%35%5%35%446%39%
2217
21st to endDay
19%7%25%6%35%5%47%35%
2340
May1st to 10thDay
18%8%36%6%445%5%8%33%
2340
11th to 20thDay
19%8%37%6%35%5%5%6%33%
2301
21st to endDay
10%6%26%7%5%6%6%7%10%35%
2531
June1st to 10thDay
11%6%35%5%46%5%6%8%42%
2340
11th to 20thDay
9%5%26%5%46%6%6%9%41%
2340
21st to endDay
10%5%36%6%46%6%6%9%39%
2340
July1st to 10thDay
13%6%36%5%36%6%7%11%35%
2340
11th to 20thDay
10%6%36%7%46%7%6%9%37%
2340
21st to endDay
13%6%346%47%6%7%9%36%
2547
August1st to 10thDay
10%5%246%46%6%8%9%39%
2327
11th to 20thDay
11%7%36%7%46%6%7%10%34%
2303
21st to endDay
8%5%25%6%35%6%7%9%43%
2448
September1st to 10thDay
13%5%35%5%3446%7%45%
1990
11th to 20thDay
11%5%25%435%45%9%47%
1980
21st to endDay
17%5%35%5%23446%46%
1980
October1st to 10thDay
12%425%5%2436%7%50%
1971
11th to 20thDay
15%7%25%42435%5%48%
1800
21st to endDay
21%7%35%5%23346%41%
1940
November1st to 10thDay
11%7%24424336%52%
1672
11th to 20thDay
15%9%45%5%34346%41%
1710
21st to endDay
18%10%36%5%34445%39%
1710
December1st to 10thDay
24%13%5%7%42445%5%27%
1710
11th to 20thDay
18%14%48%5%34445%32%
2153
21st to endDay
17%19%48%7%45%5%5%6%21%
3124
January1st to 10thNight
17%12%5%10%7%345%5%5%28%
2459
11th to 20thNight
22%15%5%8%5%345%45%25%
2386
21st to endNight
18%11%6%8%6%3435%5%31%
2574
February1st to 10thNight
21%13%5%8%5%34445%27%
2277
11th to 20thNight
21%11%5%8%6%34435%30%
2098
21st to endNight
23%13%48%5%35%445%27%
1776
March1st to 10thNight
18%10%45%5%33345%39%
2093
11th to 20thNight
19%9%36%6%3445%7%34%
1980
21st to endNight
15%10%37%7%3445%7%34%
2178
April1st to 10thNight
15%7%244245%6%8%41%
1944
11th to 20thNight
15%8%245%3345%8%43%
1692
21st to endNight
18%7%36%5%345%5%6%39%
1620
May1st to 10thNight
18%5%36%6%346%6%7%36%
1620
11th to 20thNight
16%6%36%436%6%6%8%36%
1592
21st to endNight
9%6%246%35%5%7%11%41%
1744
June1st to 10thNight
8%5%24446%5%8%10%45%
1620
11th to 20thNight
6%435%5%35%6%6%10%46%
1620
21st to endNight
9%325%6%35%5%8%11%43%
1620
July1st to 10thNight
11%6%25%5%35%5%5%10%42%
1620
11th to 20thNight
6%4245%35%6%8%11%46%
1620
21st to endNight
9%5%26%5%45%5%7%8%44%
1771
August1st to 10thNight
7%425%5%35%5%7%11%46%
1611
11th to 20thNight
9%5%26%6%45%5%8%9%43%
1598
21st to endNight
7%5%25%4245%6%9%50%
1903
September1st to 10thNight
10%5%245%45%5%5%8%47%
1950
11th to 20thNight
10%5%345%3445%7%50%
1980
21st to endNight
10%6%35%5%3445%7%47%
1980
October1st to 10thNight
11%425%42345%8%52%
1988
11th to 20thNight
16%5%35%5%24447%47%
2160
21st to endNight
18%7%26%5%34446%42%
2414
November1st to 10thNight
11%7%34434346%50%
2406
11th to 20thNight
16%8%35%5%3345%6%43%
2470
21st to endNight
17%11%35%42445%6%40%
2470
December1st to 10thNight
22%13%46%5%34445%30%
2470
11th to 20thNight
17%12%5%9%5%34346%31%
3042
21st to endNight
18%18%5%8%6%45%45%6%20%
4532

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
59%5%8%17%10%1
1707
11th to 20thDay
65%38%16%6%1
1647
21st to endDay
57%310%20%9%2
1782
February1st to 10thDay
61%48%18%9%1
1682
11th to 20thDay
57%48%19%10%2
1758
21st to endDay
57%48%18%10%3
1480
March1st to 10thDay
50%49%23%13%2
1866
11th to 20thDay
54%49%19%11%3
1980
21st to endDay
54%49%21%9%2
2178
April1st to 10thDay
46%49%24%13%3
2031
11th to 20thDay
46%5%8%19%17%5%
2217
21st to endDay
48%6%11%21%11%3
2340
May1st to 10thDay
49%6%12%22%9%2
2340
11th to 20thDay
51%6%11%19%11%1
2305
21st to endDay
41%11%13%22%13%1
2531
June1st to 10thDay
39%7%11%26%16%1
2340
11th to 20thDay
39%9%13%21%17%2
2340
21st to endDay
41%8%12%20%15%3
2340
July1st to 10thDay
42%10%14%18%16%1
2275
11th to 20thDay
41%9%12%20%14%2
2271
21st to endDay
41%8%13%24%12%2
2405
August1st to 10thDay
38%10%15%23%13%1
2314
11th to 20thDay
43%8%13%23%12%1
2303
21st to endDay
34%8%15%24%15%4
2448
September1st to 10thDay
38%6%13%20%17%6%
1990
11th to 20thDay
35%5%12%25%22%2
1980
21st to endDay
39%49%25%21%2
1980
October1st to 10thDay
33%6%12%24%22%3
1971
11th to 20thDay
38%48%25%21%3
1800
21st to endDay
45%310%24%17%2
1940
November1st to 10thDay
36%47%26%22%4
1672
11th to 20thDay
45%38%22%19%3
1710
21st to endDay
49%38%19%18%2
1710
December1st to 10thDay
59%411%18%8%1
1710
11th to 20thDay
56%310%17%14%1
2150
21st to endDay
63%411%16%5%1
3124
January1st to 10thNight
58%48%16%11%1
2459
11th to 20thNight
62%48%15%9%1
2386
21st to endNight
56%39%21%8%2
2574
February1st to 10thNight
59%49%18%9%1
2277
11th to 20thNight
58%38%19%11%1
2099
21st to endNight
62%39%13%10%3
1776
March1st to 10thNight
49%46%20%18%3
2093
11th to 20thNight
51%5%10%21%12%2
1980
21st to endNight
50%5%10%21%12%2
2178
April1st to 10thNight
39%6%11%23%18%2
1944
11th to 20thNight
40%5%11%19%19%7%
1692
21st to endNight
46%6%11%22%14%2
1620
May1st to 10thNight
46%7%11%21%11%4
1620
11th to 20thNight
45%9%12%21%12%2
1593
21st to endNight
35%10%16%21%16%2
1745
June1st to 10thNight
32%8%16%25%16%4
1620
11th to 20thNight
31%9%14%23%19%4
1620
21st to endNight
33%10%14%24%14%5%
1620
July1st to 10thNight
37%9%13%20%17%4
1575
11th to 20thNight
29%10%16%23%18%4
1566
21st to endNight
36%8%13%28%14%1
1672
August1st to 10thNight
32%8%16%27%16%2
1600
11th to 20thNight
36%9%15%25%15%1
1598
21st to endNight
29%8%13%27%18%5%
1903
September1st to 10thNight
34%7%13%21%18%8%
1950
11th to 20thNight
33%5%12%22%24%3
1980
21st to endNight
37%6%8%22%25%2
1980
October1st to 10thNight
31%5%11%25%22%5%
1988
11th to 20thNight
38%49%23%22%4
2160
21st to endNight
45%48%21%19%4
2414
November1st to 10thNight
37%48%24%22%5%
2406
11th to 20thNight
43%48%18%22%5%
2470
21st to endNight
46%410%23%15%2
2470
December1st to 10thNight
56%5%10%18%10%1
2470
11th to 20thNight
55%38%21%12%1
3044
21st to endNight
63%5%10%14%8%
4532

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
30%21%33%13%21
270
11th to 20thDay
38%19%32%11%
249
21st to endDay
32%30%26%11%1
264
February1st to 10thDay
35%25%28%9%3
240
11th to 20thDay
41%27%27%5%
240
21st to endDay
37%21%34%7%1
198
March1st to 10thDay
33%22%31%11%3
306
11th to 20thDay
29%22%30%14%5%
420
21st to endDay
31%19%28%16%5%
462
April1st to 10thDay
25%20%27%20%8%1
420
11th to 20thDay
22%18%31%18%7%3
412
21st to endDay
27%17%31%17%6%2
420
May1st to 10thDay
27%17%28%17%9%4
423
11th to 20thDay
22%11%30%20%12%4
447
21st to endDay
15%7%25%27%17%9%
485
June1st to 10thDay
15%6%24%32%16%8%
450
11th to 20thDay
12%8%25%31%16%8%
450
21st to endDay
13%7%27%25%18%10%
450
July1st to 10thDay
16%5%16%22%20%21%
445
11th to 20thDay
11%6%21%31%19%13%
444
21st to endDay
14%420%28%22%13%
488
August1st to 10thDay
15%318%27%23%13%
446
11th to 20thDay
15%416%32%22%11%
439
21st to endDay
10%5%16%30%25%13%
495
September1st to 10thDay
16%416%23%28%13%
450
11th to 20thDay
13%315%26%30%12%
450
21st to endDay
19%8%20%25%23%5%
450
October1st to 10thDay
16%7%22%28%20%6%
450
11th to 20thDay
18%12%30%22%14%3
450
21st to endDay
25%13%31%23%7%1
455
November1st to 10thDay
17%13%35%25%8%2
270
11th to 20thDay
31%16%28%18%6%1
270
21st to endDay
29%15%37%15%41
270
December1st to 10thDay
32%22%29%13%4
270
11th to 20thDay
29%18%33%14%5%
270
21st to endDay
34%21%32%11%1
297
January1st to 10thNight
27%20%30%19%4
760
11th to 20thNight
32%17%29%18%3
735
21st to endNight
26%19%34%19%2
792
February1st to 10thNight
30%14%34%20%3
720
11th to 20thNight
30%20%32%17%1
703
21st to endNight
34%15%34%15%1
592
March1st to 10thNight
27%17%31%22%5%
720
11th to 20thNight
27%16%30%20%7%
720
21st to endNight
21%16%29%27%7%
792
April1st to 10thNight
23%13%29%27%8%
684
11th to 20thNight
20%11%28%27%12%1
533
21st to endNight
21%8%34%28%8%1
540
May1st to 10thNight
20%9%28%27%12%2
540
11th to 20thNight
18%7%23%34%17%2
531
21st to endNight
11%220%33%29%4
584
June1st to 10thNight
9%321%41%22%3
540
11th to 20thNight
8%317%40%28%4
540
21st to endNight
11%220%37%26%4
540
July1st to 10thNight
14%215%28%32%10%
525
11th to 20thNight
6%212%38%37%5%
522
21st to endNight
12%211%35%35%6%
591
August1st to 10thNight
10%28%37%37%7%
537
11th to 20thNight
11%210%35%35%7%
534
21st to endNight
10%212%33%37%7%
594
September1st to 10thNight
12%313%32%35%6%
690
11th to 20thNight
13%315%29%35%6%
720
21st to endNight
13%5%22%30%28%2
720
October1st to 10thNight
13%6%19%31%27%4
720
11th to 20thNight
19%8%27%29%15%2
720
21st to endNight
22%12%27%25%12%2
792
November1st to 10thNight
17%9%26%30%17%2
740
11th to 20thNight
21%13%30%25%10%
760
21st to endNight
24%14%24%28%9%1
760
December1st to 10thNight
30%16%26%24%4
760
11th to 20thNight
25%13%32%24%6%1
760
21st to endNight
29%16%28%24%3
836
Page generated at 2024-01-11 04:22:41. Version ac07

Copyright 2024 Attilla Danko


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