Hiram College
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Hiram College clear sky chart from 2005-11-06 to 2024-01-27.

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
32%
23385
14%
75079
9%
23331
38%
23331
17%
53424

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
10%
758
10%
2459
2%
757
17%
757
7%
1988
January11th to 20thNight
13%
760
7%
2470
4%
760
16%
760
6%
2036
January21st to endNight
13%
820
9%
2664
4%
820
19%
820
8%
2201
February1st to 10thNight
13%
720
8%
2340
3%
720
19%
720
8%
1885
February11th to 20thNight
13%
702
9%
2247
4%
700
20%
700
9%
1797
February21st to endNight
13%
592
12%
1776
2%
592
23%
592
10%
1385
March1st to 10thNight
20%
720
16%
2012
7%
720
28%
720
15%
1488
March11th to 20thNight
24%
720
18%
1980
9%
720
31%
720
17%
1425
March21st to endNight
23%
792
16%
2178
9%
792
29%
792
17%
1608
April1st to 10thNight
23%
720
12%
1926
5%
720
28%
720
19%
1410
April11th to 20thNight
26%
604
18%
1668
6%
604
34%
604
22%
1162
April21st to endNight
29%
540
18%
1620
7%
540
37%
540
22%
1094
May1st to 10thNight
34%
540
12%
1620
6%
540
39%
540
18%
1150
May11th to 20thNight
40%
531
17%
1593
12%
531
44%
531
23%
1069
May21st to endNight
52%
497
16%
1660
12%
497
59%
497
30%
973
June1st to 10thNight
44%
360
15%
1440
15%
360
53%
360
22%
856
June11th to 20thNight
50%
360
18%
1440
19%
360
61%
360
22%
833
June21st to endNight
47%
360
18%
1440
18%
360
56%
360
24%
815
July1st to 10thNight
64%
471
15%
1521
17%
471
66%
471
31%
910
July11th to 20thNight
60%
522
18%
1566
16%
522
64%
522
35%
927
July21st to endNight
59%
591
17%
1672
14%
558
62%
558
31%
1040
August1st to 10thNight
63%
537
19%
1600
15%
534
66%
534
33%
946
August11th to 20thNight
61%
534
20%
1598
16%
534
63%
534
30%
984
August21st to endNight
56%
632
22%
1820
15%
632
60%
632
34%
1095
September1st to 10thNight
55%
720
21%
1862
13%
720
59%
720
33%
1197
September11th to 20thNight
61%
720
26%
1980
19%
720
64%
720
37%
1168
September21st to endNight
45%
720
21%
1980
16%
720
49%
720
28%
1307
October1st to 10thNight
42%
720
20%
2116
16%
720
47%
720
27%
1344
October11th to 20thNight
30%
720
16%
2160
10%
720
39%
720
19%
1499
October21st to endNight
24%
792
18%
2376
10%
792
34%
792
16%
1702
November1st to 10thNight
35%
740
20%
2383
15%
740
44%
740
22%
1513
November11th to 20thNight
20%
760
15%
2536
8%
760
29%
760
13%
1853
November21st to endNight
16%
760
11%
2660
6%
760
24%
760
11%
2012
December1st to 10thNight
15%
760
7%
2660
4%
760
20%
760
8%
2121
December11th to 20thNight
14%
759
8%
3261
3%
758
22%
758
6%
2547
December21st to endNight
13%
831
4%
4795
2%
817
19%
817
3%
4084

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
16%11%48%6%35%5%5%7%30%
74723
Night
16%11%5%8%6%35%5%5%6%31%
75324
TransparencyDay
53%5%11%19%10%1
74444
Night
53%411%19%11%1
75122
SeeingDay
22%15%28%20%11%4
13512
Night
21%13%27%25%12%1
23396

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
17%17%9%11%8%45%446%15%
1706
11th to 20thDay
18%19%9%12%7%44445%14%
1710
21st to endDay
16%19%9%15%9%3443313%
1836
February1st to 10thDay
17%19%7%11%9%44335%18%
1620
11th to 20thDay
15%15%8%13%10%4445%5%18%
1599
21st to endDay
18%16%413%5%35%445%23%
1480
March1st to 10thDay
18%12%7%8%5%34447%27%
1948
11th to 20thDay
18%13%48%7%34436%29%
1980
21st to endDay
21%12%6%8%5%3435%5%27%
2178
April1st to 10thDay
15%12%5%7%6%345%5%7%32%
2034
11th to 20thDay
19%11%36%6%35%446%32%
2257
21st to endDay
21%11%36%5%34346%34%
2340
May1st to 10thDay
17%10%37%7%45%6%47%30%
2340
11th to 20thDay
19%9%36%6%35%5%5%6%33%
2301
21st to endDay
11%6%25%7%46%6%5%9%38%
2614
June1st to 10thDay
15%6%36%6%45%6%5%8%37%
2520
11th to 20thDay
13%8%36%5%445%6%8%38%
2520
21st to endDay
12%426%5%35%6%6%10%40%
2520
July1st to 10thDay
10%6%36%6%35%5%6%9%41%
2389
11th to 20thDay
11%6%25%5%46%6%6%10%38%
2340
21st to endDay
10%5%35%6%36%7%7%9%38%
2547
August1st to 10thDay
9%6%35%6%45%6%7%9%39%
2327
11th to 20thDay
11%7%37%6%46%7%8%9%33%
2303
21st to endDay
11%6%25%6%46%7%7%9%37%
2516
September1st to 10thDay
15%6%35%5%45%46%7%39%
2095
11th to 20thDay
12%6%26%5%35%5%7%10%40%
1980
21st to endDay
19%9%26%434447%38%
1980
October1st to 10thDay
15%6%37%6%45%45%7%37%
1842
11th to 20thDay
22%11%37%6%34445%31%
1800
21st to endDay
23%12%47%6%3445%6%25%
1980
November1st to 10thDay
12%10%5%7%6%346%5%6%37%
1690
11th to 20thDay
18%16%47%5%34446%27%
1641
21st to endDay
18%17%7%8%6%35%5%46%19%
1520
December1st to 10thDay
17%21%10%12%7%3443415%
1520
11th to 20thDay
18%17%9%14%5%35%45%415%
1910
21st to endDay
26%24%9%9%7%3333310%
2840
January1st to 10thNight
17%17%8%13%8%345%45%18%
2459
11th to 20thNight
19%17%7%12%7%445%4416%
2470
21st to endNight
16%17%9%13%9%3444417%
2664
February1st to 10thNight
19%15%6%12%8%45%445%18%
2340
11th to 20thNight
16%14%7%13%8%45%445%20%
2245
21st to endNight
22%12%5%11%6%44435%23%
1776
March1st to 10thNight
16%12%6%8%6%35%445%30%
2012
11th to 20thNight
18%10%47%5%35%45%7%33%
1980
21st to endNight
19%11%5%8%6%3445%432%
2178
April1st to 10thNight
16%12%5%7%6%26%45%6%32%
1926
11th to 20thNight
15%10%46%6%35%5%6%7%34%
1668
21st to endNight
15%8%46%6%35%5%5%7%35%
1620
May1st to 10thNight
17%9%37%6%36%5%6%6%32%
1620
11th to 20thNight
15%8%45%6%35%5%5%8%36%
1592
21st to endNight
10%5%245%45%6%7%11%42%
1659
June1st to 10thNight
10%7%35%5%36%6%7%7%42%
1440
11th to 20thNight
10%5%26%5%45%5%7%8%42%
1440
21st to endNight
12%4345%35%5%7%10%42%
1440
July1st to 10thNight
7%5%25%6%35%46%8%49%
1566
11th to 20thNight
8%5%345%45%5%7%8%47%
1620
21st to endNight
9%5%25%6%35%6%5%9%44%
1771
August1st to 10thNight
6%5%25%5%35%6%6%8%49%
1611
11th to 20thNight
9%5%36%5%35%5%5%8%45%
1598
21st to endNight
10%5%25%5%435%6%8%47%
1820
September1st to 10thNight
13%5%24435%5%5%7%46%
1862
11th to 20thNight
11%4244345%48%51%
1980
21st to endNight
15%6%36%6%345%5%6%41%
1980
October1st to 10thNight
14%7%345%345%5%8%42%
2116
11th to 20thNight
19%8%37%6%35%6%5%6%33%
2160
21st to endNight
25%10%36%5%3446%6%30%
2376
November1st to 10thNight
14%10%36%5%345%5%7%38%
2383
11th to 20thNight
17%15%6%7%5%35%45%6%28%
2536
21st to endNight
18%16%6%8%6%35%45%5%23%
2660
December1st to 10thNight
20%18%8%10%6%3435%5%18%
2660
11th to 20thNight
16%19%8%10%7%34445%20%
3285
21st to endNight
26%20%8%9%6%4443411%
4811

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
71%311%10%4
1707
11th to 20thDay
74%310%10%3
1710
21st to endDay
76%37%10%31
1836
February1st to 10thDay
71%39%12%5%
1620
11th to 20thDay
69%38%14%6%
1608
21st to endDay
64%310%14%6%2
1480
March1st to 10thDay
58%312%20%6%
1948
11th to 20thDay
58%49%17%10%1
1980
21st to endDay
60%38%18%10%2
2178
April1st to 10thDay
52%412%18%13%1
2034
11th to 20thDay
53%411%17%13%2
2257
21st to endDay
53%410%21%10%2
2340
May1st to 10thDay
54%5%11%19%9%2
2340
11th to 20thDay
51%5%11%17%14%2
2305
21st to endDay
41%7%13%24%12%2
2614
June1st to 10thDay
45%6%11%25%12%1
2520
11th to 20thDay
44%5%15%21%14%2
2520
21st to endDay
39%6%12%25%15%2
2520
July1st to 10thDay
41%6%11%24%16%2
2324
11th to 20thDay
41%6%13%25%15%1
2271
21st to endDay
39%7%13%23%16%2
2405
August1st to 10thDay
39%7%14%28%12%1
2314
11th to 20thDay
43%7%14%23%10%2
2303
21st to endDay
41%7%13%23%14%3
2516
September1st to 10thDay
42%5%14%21%15%3
2095
11th to 20thDay
38%5%15%26%15%1
1980
21st to endDay
46%49%25%14%1
1980
October1st to 10thDay
46%5%11%23%15%1
1842
11th to 20thDay
55%5%10%21%9%1
1800
21st to endDay
59%413%14%9%1
1980
November1st to 10thDay
46%5%12%22%14%1
1690
11th to 20thDay
57%5%10%18%7%3
1641
21st to endDay
65%410%14%7%
1520
December1st to 10thDay
74%48%12%3
1520
11th to 20thDay
71%5%8%13%3
1906
21st to endDay
81%38%6%2
2840
January1st to 10thNight
69%39%13%6%
2459
11th to 20thNight
71%410%12%3
2470
21st to endNight
71%39%13%41
2664
February1st to 10thNight
69%310%13%4
2340
11th to 20thNight
67%48%15%6%
2247
21st to endNight
64%48%16%8%1
1776
March1st to 10thNight
56%39%22%9%
2012
11th to 20thNight
51%5%11%19%12%2
1980
21st to endNight
55%47%19%13%2
2178
April1st to 10thNight
52%5%11%17%13%2
1926
11th to 20thNight
48%5%12%18%15%2
1668
21st to endNight
46%5%11%20%14%3
1620
May1st to 10thNight
52%410%17%13%3
1620
11th to 20thNight
46%5%11%20%14%4
1593
21st to endNight
35%6%17%26%15%2
1660
June1st to 10thNight
40%6%11%25%15%3
1440
11th to 20thNight
38%5%14%22%18%2
1440
21st to endNight
37%6%14%25%18%1
1440
July1st to 10thNight
36%5%11%24%20%4
1521
11th to 20thNight
31%7%13%26%20%2
1566
21st to endNight
36%6%15%24%16%3
1672
August1st to 10thNight
32%7%14%28%18%1
1600
11th to 20thNight
36%6%16%27%13%2
1598
21st to endNight
34%5%14%26%18%4
1820
September1st to 10thNight
37%5%12%26%17%4
1862
11th to 20thNight
32%414%27%21%1
1980
21st to endNight
42%412%23%18%1
1980
October1st to 10thNight
40%5%13%23%18%1
2116
11th to 20thNight
50%411%23%12%1
2160
21st to endNight
54%411%20%10%1
2376
November1st to 10thNight
43%5%12%24%14%3
2383
11th to 20thNight
58%410%18%8%3
2536
21st to endNight
62%312%17%5%
2660
December1st to 10thNight
68%311%13%5%
2660
11th to 20thNight
67%312%15%3
3288
21st to endNight
77%410%8%1
4811

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
33%26%27%10%4
270
11th to 20thDay
31%27%30%8%3
270
21st to endDay
30%33%26%8%21
282
February1st to 10thDay
33%28%33%6%
240
11th to 20thDay
33%33%29%41
240
21st to endDay
34%30%31%5%
198
March1st to 10thDay
25%26%32%12%5%
388
11th to 20thDay
28%21%34%11%5%1
420
21st to endDay
33%21%26%15%4
462
April1st to 10thDay
24%23%30%14%7%1
420
11th to 20thDay
28%17%28%16%8%3
412
21st to endDay
29%18%29%17%5%2
420
May1st to 10thDay
28%18%28%16%6%3
423
11th to 20thDay
25%12%30%21%8%4
447
21st to endDay
15%9%29%24%17%6%
485
June1st to 10thDay
14%12%36%24%12%2
450
11th to 20thDay
19%10%26%25%15%4
450
21st to endDay
15%9%33%24%15%4
450
July1st to 10thDay
13%423%28%22%10%
445
11th to 20thDay
15%427%29%17%9%
444
21st to endDay
11%6%29%30%16%8%
488
August1st to 10thDay
13%5%20%32%20%11%
446
11th to 20thDay
15%6%26%26%18%10%
439
21st to endDay
12%5%24%29%22%8%
495
September1st to 10thDay
14%8%21%28%20%8%
450
11th to 20thDay
13%419%30%22%12%
450
21st to endDay
22%10%25%21%16%6%
450
October1st to 10thDay
14%12%29%22%19%4
450
11th to 20thDay
27%17%31%18%6%2
450
21st to endDay
31%17%29%18%5%
495
November1st to 10thDay
21%22%28%15%11%2
288
11th to 20thDay
32%19%29%15%5%
237
21st to endDay
27%21%40%11%1
180
December1st to 10thDay
31%26%27%12%32
180
11th to 20thDay
26%28%34%11%1
180
21st to endDay
34%24%29%10%2
218
January1st to 10thNight
27%23%34%12%3
760
11th to 20thNight
30%23%29%16%3
760
21st to endNight
25%23%31%18%3
820
February1st to 10thNight
30%21%29%19%1
720
11th to 20thNight
26%21%35%16%2
703
21st to endNight
30%21%31%15%2
592
March1st to 10thNight
24%19%32%21%4
720
11th to 20thNight
24%19%29%21%7%1
720
21st to endNight
26%15%31%22%6%1
792
April1st to 10thNight
23%16%32%23%6%
720
11th to 20thNight
21%15%35%20%8%1
604
21st to endNight
19%10%37%27%7%
540
May1st to 10thNight
22%9%26%33%10%1
540
11th to 20thNight
18%7%27%34%12%2
531
21st to endNight
12%326%34%22%2
499
June1st to 10thNight
10%335%38%13%1
360
11th to 20thNight
13%5%23%43%16%1
360
21st to endNight
12%5%29%33%20%1
360
July1st to 10thNight
7%216%40%29%5%
471
11th to 20thNight
10%220%37%27%4
522
21st to endNight
10%318%40%27%2
591
August1st to 10thNight
9%316%40%28%4
537
11th to 20thNight
11%314%37%31%4
534
21st to endNight
11%320%33%28%5%
632
September1st to 10thNight
15%5%18%31%27%4
720
11th to 20thNight
12%415%37%28%5%
720
21st to endNight
17%8%23%28%20%4
720
October1st to 10thNight
20%7%25%26%19%3
720
11th to 20thNight
22%12%31%25%9%1
720
21st to endNight
30%12%29%23%5%
792
November1st to 10thNight
20%13%26%29%11%1
740
11th to 20thNight
24%21%29%18%6%1
760
21st to endNight
28%18%32%16%5%
760
December1st to 10thNight
32%19%28%16%5%
760
11th to 20thNight
27%23%29%17%4
760
21st to endNight
31%19%30%18%2
836
Page generated at 2024-01-24 09:37:29. Version ac07

Copyright 2024 Attilla Danko


Hiram College Clear Sky Chart |Charts Home