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 2018-02-14.

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
43%
16030
19%
48641
14%
15986
49%
15986
24%
32063

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
18%
780
13%
2522
7%
776
26%
776
13%
1915
January16th to endNight
20%
832
17%
2704
8%
832
30%
832
15%
1936
February1st to 15thNight
20%
760
12%
2333
5%
757
28%
757
15%
1711
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
42%
540
21%
1645
11%
540
49%
540
26%
1069
May1st to 15thNight
40%
540
14%
1620
9%
540
45%
540
19%
1159
May16th to endNight
61%
562
18%
1684
14%
561
64%
561
28%
1057
June1st to 15thNight
68%
540
18%
1620
16%
540
71%
540
38%
931
June16th to endNight
66%
540
17%
1514
13%
540
69%
540
36%
925
July1st to 15thNight
60%
510
14%
1468
13%
510
62%
510
27%
958
July16th to endNight
74%
564
20%
1595
17%
531
76%
531
35%
932
August1st to 15thNight
74%
539
22%
1609
19%
536
76%
536
36%
942
August16th to endNight
76%
573
24%
1838
25%
573
77%
573
38%
991
September1st to 15thNight
65%
678
25%
1938
21%
678
67%
678
34%
1171
September16th to endNight
60%
717
29%
1980
24%
717
62%
717
33%
1224
October1st to 15thNight
56%
720
29%
2024
24%
720
61%
720
37%
1198
October16th to endNight
39%
768
26%
2364
20%
768
49%
768
27%
1478
November1st to 15thNight
45%
760
26%
2471
21%
760
54%
760
29%
1454
November16th to endNight
34%
780
22%
2535
16%
780
44%
780
22%
1638
December1st to 15thNight
29%
780
13%
2535
8%
780
35%
780
15%
1815
December16th to endNight
20%
832
15%
2704
6%
832
30%
832
13%
2028

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%
49403
Night
14%7%35%42445%7%40%
48833
Cloud CoverDay
15%7%35%5%3445%7%37%
49413
Night
14%7%35%42445%7%40%
48837
TransparencyDay
45%6%11%20%13%2
49114
Night
43%6%11%21%15%2
48641
SeeingDay
17%8%22%22%17%10%
5930
Night
18%8%25%28%18%2
16031

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%9%5%8%5%25%446%27%
1746
16th to endDay
18%11%5%7%424335%32%
1872
February1st to 15thDay
18%10%5%8%6%34345%30%
1828
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%35%6%7%10%38%
2340
16th to endDay
7%5%35%5%45%6%6%9%40%
2361
September1st to 15thDay
15%5%14435%5%5%7%41%
2010
16th to endDay
13%5%14423446%47%
1980
October1st to 15thDay
12%424423446%49%
1935
16th to endDay
19%6%24412235%46%
1857
November1st to 15thDay
13%7%24423335%48%
1717
16th to endDay
16%9%345%2335%5%41%
1755
December1st to 15thDay
23%10%35%5%24435%30%
1755
16th to endDay
20%13%46%42435%5%28%
1872
January1st to 15thNight
17%10%5%9%7%34445%27%
2522
16th to endNight
19%10%5%6%5%2433433%
2704
February1st to 15thNight
20%9%5%7%5%33345%30%
2331
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
5%3134346%7%9%50%
1620
16th to endNight
5%32432447%10%52%
1838
September1st to 15thNight
12%42333435%8%48%
1938
16th to endNight
10%434424346%51%
1980
October1st to 15thNight
10%41432345%7%51%
2024
16th to endNight
15%6%24424336%44%
2364
November1st to 15thNight
13%5%25%224345%49%
2471
16th to endNight
18%8%34323345%41%
2535
December1st to 15thNight
21%9%36%42435%5%32%
2535
16th to endNight
21%12%46%5%34346%26%
2704

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%9%5%8%5%34445%28%
1746
16th to endDay
17%12%5%7%5%24335%32%
1872
February1st to 15thDay
18%10%48%6%34346%29%
1828
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%425%5%45%5%7%10%39%
2340
16th to endDay
8%5%26%6%35%5%6%9%39%
2361
September1st to 15thDay
15%4145%25%5%5%7%41%
2010
16th to endDay
13%5%24423436%48%
1980
October1st to 15thDay
12%5%14423346%50%
1935
16th to endDay
19%6%23422245%46%
1857
November1st to 15thDay
13%6%2442333449%
1717
16th to endDay
16%9%34422345%41%
1755
December1st to 15thDay
23%10%35%434445%30%
1755
16th to endDay
20%13%46%5%2425%5%29%
1872
January1st to 15thNight
18%10%5%9%6%24445%27%
2522
16th to endNight
19%11%46%42434433%
2704
February1st to 15thNight
20%9%47%5%24345%31%
2324
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%3134345%7%10%49%
1620
16th to endNight
5%32332446%9%53%
1838
September1st to 15thNight
11%423325%35%8%47%
1938
16th to endNight
10%434424336%50%
1980
October1st to 15thNight
10%414323448%51%
2024
16th to endNight
15%6%245%24346%45%
2364
November1st to 15thNight
13%5%14323436%49%
2471
16th to endNight
18%9%34323345%41%
2535
December1st to 15thNight
22%9%36%424445%31%
2535
16th to endNight
21%12%46%5%34446%26%
2704

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
57%49%17%10%
1747
16th to endDay
54%310%23%6%1
1872
February1st to 15thDay
56%49%20%7%1
1830
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%13%1
2327
16th to endDay
37%8%13%21%14%3
2361
September1st to 15thDay
40%8%11%16%18%5%
2010
16th to endDay
37%5%8%23%22%2
1980
October1st to 15thDay
34%5%9%25%20%3
1935
16th to endDay
41%39%27%15%2
1857
November1st to 15thDay
39%38%24%19%5%
1717
16th to endDay
45%38%22%18%1
1755
December1st to 15thDay
55%5%11%16%10%1
1755
16th to endDay
57%5%11%17%7%
1872
January1st to 15thNight
58%6%7%13%12%1
2522
16th to endNight
54%39%20%9%1
2704
February1st to 15thNight
55%410%19%8%1
2333
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
28%8%15%23%20%2
1609
16th to endNight
25%7%15%27%20%4
1838
September1st to 15thNight
33%5%14%21%18%7%
1938
16th to endNight
34%5%7%22%27%2
1980
October1st to 15thNight
30%5%11%26%20%5%
2024
16th to endNight
41%39%23%19%3
2364
November1st to 15thNight
37%38%21%22%5%
2471
16th to endNight
45%39%24%16%1
2535
December1st to 15thNight
53%5%11%18%9%1
2535
16th to endNight
58%410%17%7%
2704

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
29%15%33%14%6%
135
16th to endDay
27%25%34%11%1
144
February1st to 15thDay
25%20%36%15%1
130
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%29%21%29%23%
313
16th to endDay
10%212%26%25%23%
332
September1st to 15thDay
16%211%21%26%19%
315
16th to endDay
16%312%21%30%15%
314
October1st to 15thDay
14%6%22%26%21%8%
315
16th to endDay
15%10%26%24%18%3
273
November1st to 15thDay
20%14%27%20%14%3
135
16th to endDay
20%14%34%24%5%2
135
December1st to 15thDay
21%22%29%17%7%1
135
16th to endDay
29%23%39%6%
144
January1st to 15thNight
24%14%35%20%5%
780
16th to endNight
24%15%34%23%1
832
February1st to 15thNight
27%12%34%24%
760
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%33%43%6%
539
16th to endNight
6%10%31%43%8%
573
September1st to 15thNight
14%211%28%37%6%
678
16th to endNight
13%315%29%32%6%
717
October1st to 15thNight
12%5%20%30%25%5%
720
16th to endNight
19%7%29%27%14%2
768
November1st to 15thNight
16%8%26%26%19%2
760
16th to endNight
25%9%27%25%10%
780
December1st to 15thNight
27%12%24%26%7%
780
16th to endNight
28%12%33%21%3
832
Page generated at 2018-02-15 10:58:46. Version ac04

Copyright 2018 A. Danko


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