Millersburg
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Millersburg 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
43%
15305
19%
46392
13%
15261
49%
15261
24%
30636

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%
720
13%
2327
7%
716
25%
716
13%
1776
January16th to endNight
20%
768
16%
2496
8%
768
30%
768
15%
1804
February1st to 15thNight
20%
704
13%
2161
5%
701
28%
701
16%
1570
February16th to endNight
17%
631
13%
1893
6%
631
24%
631
15%
1391
March1st to 15thNight
24%
720
17%
2079
9%
720
31%
720
17%
1480
March16th to endNight
32%
768
14%
2112
8%
768
37%
768
22%
1486
April1st to 15thNight
35%
596
20%
1854
11%
596
45%
596
26%
1174
April16th to endNight
41%
540
20%
1645
11%
540
49%
540
26%
1069
May1st to 15thNight
40%
540
14%
1620
9%
540
44%
540
19%
1159
May16th to endNight
61%
562
18%
1684
14%
561
64%
561
28%
1057
June1st to 15thNight
67%
540
18%
1620
16%
540
70%
540
38%
931
June16th to endNight
66%
540
17%
1514
13%
540
69%
540
36%
925
July1st to 15thNight
60%
510
14%
1468
12%
510
62%
510
27%
958
July16th to endNight
74%
564
20%
1595
17%
531
76%
531
35%
932
August1st to 15thNight
74%
527
23%
1575
20%
524
76%
524
36%
915
August16th to endNight
75%
525
23%
1684
23%
525
76%
525
38%
917
September1st to 15thNight
66%
621
26%
1776
23%
621
69%
621
34%
1069
September16th to endNight
59%
657
27%
1815
22%
657
61%
657
32%
1145
October1st to 15thNight
55%
660
30%
1855
25%
660
61%
660
38%
1092
October16th to endNight
39%
704
24%
2167
19%
704
49%
704
27%
1358
November1st to 15thNight
46%
700
27%
2276
22%
700
55%
700
31%
1306
November16th to endNight
33%
720
20%
2340
15%
720
42%
720
21%
1544
December1st to 15thNight
28%
720
13%
2340
9%
720
33%
720
14%
1708
December16th to endNight
21%
768
15%
2496
6%
768
31%
768
13%
1870

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%7%35%5%3445%7%37%
47548
Night
14%7%35%42445%7%40%
46584
Cloud CoverDay
15%7%35%5%3445%7%37%
47558
Night
14%7%35%42445%7%40%
46588
TransparencyDay
45%6%11%20%13%2
47259
Night
43%6%11%21%14%2
46392
SeeingDay
17%8%21%22%18%11%
5295
Night
18%8%24%28%17%2
15306

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
20%9%6%8%5%24346%27%
1611
16th to endDay
18%11%5%7%5%24335%31%
1728
February1st to 15thDay
17%10%5%8%6%34345%30%
1699
16th to endDay
16%10%5%7%5%345%5%5%29%
1580
March1st to 15thDay
23%9%35%42344433%
1870
16th to endDay
18%8%26%6%3445%5%33%
2112
April1st to 15thDay
16%8%25%433446%39%
2103
16th to endDay
16%7%25%5%34347%39%
2313
May1st to 15thDay
21%7%35%435%5%47%32%
2331
16th to endDay
10%435%6%45%5%6%8%39%
2431
June1st to 15thDay
10%425%5%445%6%9%42%
2340
16th to endDay
8%436%6%36%5%7%8%39%
2436
July1st to 15thDay
14%5%245%36%6%7%8%34%
2394
16th to endDay
9%435%6%46%6%7%9%35%
2465
August1st to 15thDay
9%426%5%45%6%7%10%39%
2288
16th to endDay
8%5%36%5%45%6%5%9%39%
2163
September1st to 15thDay
14%5%14435%5%5%8%40%
1843
16th to endDay
14%6%145%23446%46%
1815
October1st to 15thDay
12%424423346%50%
1774
16th to endDay
20%6%24312235%46%
1702
November1st to 15thDay
12%6%24423335%50%
1582
16th to endDay
17%9%345%23345%39%
1620
December1st to 15thDay
24%10%35%5%24435%29%
1620
16th to endDay
20%13%46%42435%5%29%
1728
January1st to 15thNight
18%10%5%9%6%34445%26%
2327
16th to endNight
20%11%5%6%5%2433432%
2496
February1st to 15thNight
20%9%5%7%5%33345%31%
2159
16th to endNight
17%13%5%6%5%34346%28%
1893
March1st to 15thNight
17%8%46%5%345%45%35%
2067
16th to endNight
16%8%36%42445%7%36%
2112
April1st to 15thNight
12%5%35%5%25%45%7%42%
1854
16th to endNight
14%6%34434446%42%
1645
May1st to 15thNight
16%5%346%45%5%6%8%32%
1620
16th to endNight
7%3245%36%6%7%10%41%
1682
June1st to 15thNight
5%3144245%7%10%49%
1620
16th to endNight
6%314435%6%7%11%45%
1514
July1st to 15thNight
10%5%35%6%3445%8%42%
1557
16th to endNight
6%314426%6%7%8%48%
1703
August1st to 15thNight
6%3134346%7%9%50%
1586
16th to endNight
5%32432447%9%52%
1684
September1st to 15thNight
10%42333435%9%48%
1776
16th to endNight
11%434414336%49%
1815
October1st to 15thNight
9%414323447%52%
1855
16th to endNight
16%6%24424336%44%
2167
November1st to 15thNight
13%425%224345%51%
2276
16th to endNight
19%9%34323445%39%
2340
December1st to 15thNight
23%9%36%42435%5%30%
2340
16th to endNight
22%12%46%434346%27%
2496

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%10%6%8%5%24445%27%
1611
16th to endDay
18%12%5%7%5%24335%31%
1728
February1st to 15thDay
17%10%49%6%34346%30%
1699
16th to endDay
17%10%47%5%3446%429%
1580
March1st to 15thDay
23%9%3442343433%
1881
16th to endDay
18%8%36%6%3445%6%32%
2111
April1st to 15thDay
16%7%35%433446%39%
2103
16th to endDay
16%6%25%5%24447%39%
2313
May1st to 15thDay
21%6%35%435%5%47%32%
2331
16th to endDay
10%5%35%5%35%5%6%9%39%
2431
June1st to 15thDay
10%4245%35%5%6%9%42%
2340
16th to endDay
8%426%6%36%5%6%9%40%
2436
July1st to 15thDay
14%5%245%36%6%7%9%34%
2394
16th to endDay
10%435%6%47%6%6%9%35%
2465
August1st to 15thDay
9%415%5%45%5%6%10%39%
2288
16th to endDay
8%6%26%6%35%5%6%9%39%
2163
September1st to 15thDay
15%4145%25%5%6%7%41%
1843
16th to endDay
14%6%24433436%46%
1815
October1st to 15thDay
12%414423346%50%
1774
16th to endDay
20%6%23422235%46%
1702
November1st to 15thDay
12%6%2442333451%
1582
16th to endDay
17%9%35%422445%40%
1620
December1st to 15thDay
24%11%35%434445%29%
1620
16th to endDay
20%13%46%5%2425%5%29%
1728
January1st to 15thNight
18%10%5%9%6%24445%26%
2327
16th to endNight
20%11%5%6%42434432%
2496
February1st to 15thNight
20%9%5%7%424345%32%
2152
16th to endNight
17%13%5%5%6%34346%29%
1893
March1st to 15thNight
18%8%46%5%345%35%35%
2079
16th to endNight
16%8%36%42446%7%36%
2112
April1st to 15thNight
13%5%25%43445%7%43%
1854
16th to endNight
14%6%44435%446%42%
1645
May1st to 15thNight
17%6%25%5%35%5%6%7%32%
1619
16th to endNight
8%3245%36%5%7%9%42%
1682
June1st to 15thNight
5%3134346%6%11%49%
1620
16th to endNight
6%323435%5%8%11%45%
1514
July1st to 15thNight
10%6%246%3445%7%43%
1557
16th to endNight
6%3244246%7%9%48%
1703
August1st to 15thNight
6%3134245%7%10%50%
1586
16th to endNight
5%32332446%9%53%
1684
September1st to 15thNight
10%423325%35%9%47%
1776
16th to endNight
11%434424336%49%
1815
October1st to 15thNight
10%414323447%52%
1855
16th to endNight
16%5%245%24346%45%
2167
November1st to 15thNight
13%5%14313436%51%
2276
16th to endNight
18%9%34323345%39%
2340
December1st to 15thNight
23%9%36%424445%30%
2340
16th to endNight
22%11%46%5%34446%27%
2496

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
58%48%17%9%
1612
16th to endDay
55%310%22%6%1
1728
February1st to 15thDay
56%49%20%7%1
1701
16th to endDay
55%411%20%7%
1580
March1st to 15thDay
53%5%10%18%11%1
1881
16th to endDay
51%6%10%20%9%
2112
April1st to 15thDay
45%49%23%13%3
2103
16th to endDay
44%5%10%20%13%4
2313
May1st to 15thDay
50%7%12%17%10%1
2331
16th to endDay
40%9%15%21%11%1
2435
June1st to 15thDay
36%9%13%22%16%1
2340
16th to endDay
39%8%13%18%17%2
2436
July1st to 15thDay
43%9%14%14%14%3
2255
16th to endDay
41%9%14%21%11%2
2310
August1st to 15thDay
37%9%14%22%14%1
2275
16th to endDay
38%8%12%21%14%4
2163
September1st to 15thDay
39%8%11%15%19%5%
1843
16th to endDay
38%5%7%21%22%2
1815
October1st to 15thDay
34%5%9%25%20%3
1774
16th to endDay
42%39%27%15%2
1702
November1st to 15thDay
37%38%24%20%6%
1582
16th to endDay
47%38%20%17%1
1620
December1st to 15thDay
56%5%10%16%9%1
1620
16th to endDay
57%5%11%17%7%
1728
January1st to 15thNight
59%6%7%14%11%1
2327
16th to endNight
55%39%20%8%1
2496
February1st to 15thNight
54%410%19%8%1
2161
16th to endNight
57%312%18%8%
1893
March1st to 15thNight
50%5%9%20%11%2
2079
16th to endNight
46%7%13%21%10%
2112
April1st to 15thNight
39%5%10%21%20%2
1854
16th to endNight
41%5%11%20%13%6%
1645
May1st to 15thNight
48%8%11%20%8%2
1620
16th to endNight
34%10%15%20%15%3
1684
June1st to 15thNight
27%8%16%28%16%3
1620
16th to endNight
28%9%17%22%17%3
1514
July1st to 15thNight
39%7%12%19%16%4
1468
16th to endNight
27%9%16%26%16%2
1595
August1st to 15thNight
27%8%15%23%20%2
1575
16th to endNight
26%7%14%26%20%4
1684
September1st to 15thNight
33%6%14%19%18%7%
1776
16th to endNight
36%5%6%20%27%2
1815
October1st to 15thNight
30%5%10%27%20%5%
1855
16th to endNight
41%39%24%17%3
2167
November1st to 15thNight
35%39%21%24%6%
2276
16th to endNight
47%39%22%15%1
2340
December1st to 15thNight
55%5%10%17%8%1
2340
16th to endNight
58%410%17%7%
2496

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
33%16%34%7%6%1
90
16th to endDay
29%31%30%7%2
96
February1st to 15thDay
20%28%35%14%1
90
16th to endDay
29%12%39%14%3
81
March1st to 15thDay
28%21%29%18%2
171
16th to endDay
21%13%34%19%10%
288
April1st to 15thDay
19%15%24%24%12%2
270
16th to endDay
21%7%31%17%14%7%
270
May1st to 15thDay
23%11%25%21%11%7%
288
16th to endDay
16%423%24%17%13%
331
June1st to 15thDay
10%414%27%27%14%
315
16th to endDay
10%5%21%29%22%9%
411
July1st to 15thDay
20%418%22%20%13%
359
16th to endDay
7%13%23%25%28%
326
August1st to 15thDay
13%28%20%29%24%
297
16th to endDay
11%18%25%25%27%
268
September1st to 15thDay
14%19%20%32%22%
255
16th to endDay
18%214%22%30%11%
254
October1st to 15thDay
14%5%25%24%20%9%
255
16th to endDay
17%9%25%26%18%2
214
November1st to 15thDay
14%10%28%22%18%5%
90
16th to endDay
23%16%34%20%41
90
December1st to 15thDay
25%20%27%18%5%2
90
16th to endDay
29%21%38%9%1
96
January1st to 15thNight
25%15%34%19%4
720
16th to endNight
25%15%33%23%1
768
February1st to 15thNight
26%12%35%24%
704
16th to endNight
23%16%38%20%1
631
March1st to 15thNight
24%13%33%22%6%
720
16th to endNight
19%10%31%28%9%
768
April1st to 15thNight
17%11%32%27%11%
596
16th to endNight
15%8%30%30%13%1
540
May1st to 15thNight
18%5%28%30%14%2
540
16th to endNight
9%318%36%26%4
563
June1st to 15thNight
7%15%40%32%2
540
16th to endNight
6%117%40%30%2
540
July1st to 15thNight
13%113%34%32%4
510
16th to endNight
7%9%32%41%7%
564
August1st to 15thNight
7%8%32%44%6%
527
16th to endNight
6%10%30%44%8%
525
September1st to 15thNight
13%210%28%38%6%
621
16th to endNight
14%315%30%30%5%
657
October1st to 15thNight
11%5%22%30%24%5%
660
16th to endNight
19%7%29%27%14%1
704
November1st to 15thNight
16%8%26%26%19%2
700
16th to endNight
26%10%26%26%9%
720
December1st to 15thNight
29%12%24%24%7%
720
16th to endNight
29%12%32%22%3
768
Page generated at 2017-08-13 14:17:00. Version ac04

Copyright 2017 A. Danko


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