Cuyahoga Valley National Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cuyahoga Valley National Park 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%
23470
15%
75073
10%
23422
39%
23422
18%
53119

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
11%
758
10%
2459
2%
757
19%
757
8%
1982
January11th to 20thNight
12%
760
7%
2470
4%
760
17%
760
6%
2045
January21st to endNight
14%
820
10%
2664
5%
820
21%
820
8%
2176
February1st to 10thNight
12%
720
8%
2340
3%
720
19%
720
9%
1880
February11th to 20thNight
16%
702
11%
2220
4%
700
24%
700
10%
1745
February21st to endNight
12%
592
12%
1776
2%
592
22%
592
11%
1388
March1st to 10thNight
20%
720
17%
2030
8%
720
29%
720
16%
1480
March11th to 20thNight
26%
720
18%
1980
10%
720
34%
720
20%
1399
March21st to endNight
26%
792
16%
2178
10%
792
31%
792
18%
1601
April1st to 10thNight
24%
720
14%
1946
6%
720
30%
720
19%
1404
April11th to 20thNight
27%
577
18%
1641
8%
577
35%
577
22%
1145
April21st to endNight
29%
540
19%
1620
7%
540
38%
540
22%
1091
May1st to 10thNight
32%
540
13%
1620
6%
540
38%
540
19%
1149
May11th to 20thNight
41%
531
17%
1593
12%
531
46%
531
24%
1056
May21st to endNight
52%
560
17%
1723
12%
560
58%
560
32%
1034
June1st to 10thNight
45%
360
16%
1440
16%
360
53%
360
23%
836
June11th to 20thNight
48%
360
18%
1440
17%
360
58%
360
24%
835
June21st to endNight
51%
378
18%
1458
18%
378
60%
378
25%
832
July1st to 10thNight
63%
525
15%
1575
15%
525
65%
525
33%
961
July11th to 20thNight
60%
522
19%
1566
16%
522
64%
522
36%
922
July21st to endNight
59%
591
19%
1672
15%
558
62%
558
31%
1015
August1st to 10thNight
64%
537
20%
1600
16%
534
66%
534
34%
946
August11th to 20thNight
61%
534
21%
1598
17%
534
63%
534
32%
974
August21st to endNight
59%
614
24%
1802
17%
614
63%
614
35%
1077
September1st to 10thNight
54%
720
22%
1894
14%
720
58%
720
33%
1210
September11th to 20thNight
61%
720
28%
1980
20%
720
66%
720
39%
1169
September21st to endNight
45%
720
22%
1980
17%
720
49%
720
28%
1291
October1st to 10thNight
46%
720
20%
2096
17%
720
51%
720
29%
1313
October11th to 20thNight
29%
720
17%
2160
11%
720
39%
720
19%
1494
October21st to endNight
24%
792
18%
2377
11%
792
33%
792
16%
1732
November1st to 10thNight
33%
740
20%
2406
15%
740
42%
740
23%
1540
November11th to 20thNight
20%
760
17%
2485
9%
760
31%
760
14%
1806
November21st to endNight
20%
760
13%
2660
8%
760
27%
760
12%
1992
December1st to 10thNight
15%
760
8%
2660
4%
760
20%
760
8%
2122
December11th to 20thNight
15%
759
8%
3264
3%
759
23%
759
7%
2494
December21st to endNight
13%
826
5%
4700
3%
817
20%
817
4%
3983

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
17%11%47%6%35%5%5%7%30%
74727
Night
17%11%5%7%6%3445%6%32%
75319
TransparencyDay
54%310%20%11%1
74448
Night
54%310%20%12%2
75117
SeeingDay
23%14%28%20%11%4
13521
Night
22%11%27%26%12%1
23486

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
18%17%8%13%8%4444416%
1706
11th to 20thDay
20%19%9%12%9%4434414%
1710
21st to endDay
18%19%10%14%8%345%4411%
1836
February1st to 10thDay
18%19%7%10%9%33345%19%
1620
11th to 20thDay
16%13%8%13%9%45%45%419%
1627
21st to endDay
18%15%5%12%8%3335%423%
1480
March1st to 10thDay
19%12%7%8%6%3335%7%27%
1930
11th to 20thDay
17%15%6%9%5%34446%28%
1980
21st to endDay
23%12%6%8%5%34445%27%
2178
April1st to 10thDay
16%12%6%6%6%3445%7%32%
2013
11th to 20thDay
19%10%46%5%35%446%32%
2284
21st to endDay
22%10%46%6%34436%32%
2340
May1st to 10thDay
19%9%37%6%46%5%5%8%29%
2340
11th to 20thDay
19%9%35%6%35%5%6%7%32%
2301
21st to endDay
11%6%36%5%35%6%7%10%37%
2549
June1st to 10thDay
15%6%36%5%36%46%8%37%
2520
11th to 20thDay
14%6%36%6%35%5%6%8%37%
2520
21st to endDay
13%435%5%36%6%7%10%39%
2496
July1st to 10thDay
11%6%35%5%45%6%6%8%41%
2340
11th to 20thDay
12%5%35%6%46%6%6%9%39%
2340
21st to endDay
11%6%35%5%46%7%6%9%38%
2547
August1st to 10thDay
9%6%35%6%46%7%6%8%38%
2327
11th to 20thDay
11%6%37%6%46%7%8%10%34%
2303
21st to endDay
11%5%26%6%46%6%7%10%37%
2534
September1st to 10thDay
15%6%35%436%5%5%8%41%
2062
11th to 20thDay
12%6%26%6%35%5%5%8%42%
1980
21st to endDay
20%7%35%435%346%39%
1980
October1st to 10thDay
17%6%26%6%35%5%6%8%38%
1863
11th to 20thDay
20%9%37%5%435%5%6%33%
1800
21st to endDay
25%9%38%6%35%5%5%5%27%
1976
November1st to 10thDay
13%11%46%6%445%46%38%
1672
11th to 20thDay
19%15%5%6%6%25%35%5%29%
1691
21st to endDay
20%16%6%9%6%36%45%6%19%
1520
December1st to 10thDay
18%20%8%10%7%35%34417%
1520
11th to 20thDay
19%17%9%14%6%34446%15%
1910
21st to endDay
26%23%9%9%6%3333410%
2932
January1st to 10thNight
19%16%8%12%7%4434419%
2459
11th to 20thNight
21%18%6%13%8%3434416%
2470
21st to endNight
18%19%7%11%7%4433418%
2664
February1st to 10thNight
22%15%6%11%7%34345%19%
2340
11th to 20thNight
17%14%7%11%7%45%5%4422%
2218
21st to endNight
21%13%6%10%6%44335%24%
1776
March1st to 10thNight
18%11%6%9%5%34445%31%
2030
11th to 20thNight
17%10%5%6%5%25%5%5%6%34%
1980
21st to endNight
19%12%5%7%6%34445%31%
2178
April1st to 10thNight
16%12%46%6%445%5%7%32%
1946
11th to 20thNight
16%9%47%5%35%5%5%6%35%
1641
21st to endNight
15%8%37%5%45%5%5%7%36%
1620
May1st to 10thNight
18%8%47%7%36%5%6%6%31%
1620
11th to 20thNight
16%9%36%5%345%5%8%37%
1592
21st to endNight
10%5%25%5%346%8%12%42%
1722
June1st to 10thNight
10%5%35%5%45%6%6%7%43%
1440
11th to 20thNight
11%425%7%45%5%7%8%41%
1440
21st to endNight
12%434445%6%7%10%41%
1458
July1st to 10thNight
8%6%25%5%345%6%8%48%
1620
11th to 20thNight
8%5%25%5%35%5%6%10%47%
1620
21st to endNight
9%5%35%6%45%5%6%8%44%
1771
August1st to 10thNight
6%425%6%35%6%6%9%47%
1611
11th to 20thNight
10%6%36%5%4446%9%45%
1598
21st to endNight
10%425%5%35%6%5%8%46%
1802
September1st to 10thNight
13%5%25%5%35%5%5%6%46%
1894
11th to 20thNight
10%424434448%52%
1980
21st to endNight
15%6%26%7%345%5%7%41%
1980
October1st to 10thNight
14%6%25%5%345%6%8%43%
2096
11th to 20thNight
21%7%36%6%35%45%7%34%
2160
21st to endNight
25%10%35%6%3446%6%29%
2377
November1st to 10thNight
15%8%36%4345%6%5%40%
2406
11th to 20thNight
17%15%6%7%5%4445%6%28%
2485
21st to endNight
21%15%5%7%6%35%446%24%
2660
December1st to 10thNight
21%18%8%9%5%44345%20%
2660
11th to 20thNight
17%18%7%11%6%34345%21%
3285
21st to endNight
27%21%8%8%6%3344412%
4720

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
73%39%11%5%
1707
11th to 20thDay
76%210%9%3
1710
21st to endDay
76%37%10%3
1836
February1st to 10thDay
71%29%13%5%1
1620
11th to 20thDay
69%38%13%7%1
1636
21st to endDay
65%210%15%7%1
1480
March1st to 10thDay
59%310%21%6%
1930
11th to 20thDay
59%38%18%10%1
1980
21st to endDay
61%27%19%9%1
2178
April1st to 10thDay
54%311%19%12%1
2013
11th to 20thDay
54%211%17%14%2
2284
21st to endDay
55%29%21%11%2
2340
May1st to 10thDay
54%311%20%10%2
2340
11th to 20thDay
51%311%18%15%2
2305
21st to endDay
42%414%26%13%2
2549
June1st to 10thDay
45%310%26%14%1
2520
11th to 20thDay
45%313%23%14%1
2520
21st to endDay
39%5%12%25%17%2
2496
July1st to 10thDay
41%410%26%17%2
2275
11th to 20thDay
41%411%26%15%2
2271
21st to endDay
40%411%26%16%2
2405
August1st to 10thDay
43%412%28%13%1
2314
11th to 20thDay
43%414%25%11%2
2303
21st to endDay
41%5%12%23%15%4
2534
September1st to 10thDay
42%413%22%17%3
2062
11th to 20thDay
41%313%26%16%1
1980
21st to endDay
47%28%25%16%1
1980
October1st to 10thDay
44%410%25%15%1
1863
11th to 20thDay
52%210%23%11%1
1800
21st to endDay
59%211%16%10%1
1976
November1st to 10thDay
48%39%24%15%1
1672
11th to 20thDay
58%29%20%8%3
1691
21st to endDay
67%29%15%6%
1520
December1st to 10thDay
73%29%13%3
1520
11th to 20thDay
73%27%15%4
1906
21st to endDay
81%28%7%2
2932
January1st to 10thNight
70%27%14%7%
2459
11th to 20thNight
73%39%12%3
2470
21st to endNight
71%28%14%5%1
2664
February1st to 10thNight
69%29%14%5%
2340
11th to 20thNight
65%38%16%8%
2220
21st to endNight
65%28%15%9%2
1776
March1st to 10thNight
56%28%24%9%1
2030
11th to 20thNight
51%311%21%12%2
1980
21st to endNight
56%37%20%12%2
2178
April1st to 10thNight
53%310%18%15%1
1946
11th to 20thNight
50%311%17%16%3
1641
21st to endNight
48%211%21%15%3
1620
May1st to 10thNight
53%310%18%12%3
1620
11th to 20thNight
47%312%19%15%4
1593
21st to endNight
36%5%16%27%15%2
1723
June1st to 10thNight
40%5%10%27%16%3
1440
11th to 20thNight
40%414%21%19%2
1440
21st to endNight
37%6%12%26%17%2
1458
July1st to 10thNight
38%311%25%19%4
1575
11th to 20thNight
34%413%28%19%3
1566
21st to endNight
38%313%26%17%3
1672
August1st to 10thNight
34%412%30%18%1
1600
11th to 20thNight
37%415%28%13%2
1598
21st to endNight
35%412%27%19%4
1802
September1st to 10thNight
38%410%27%17%4
1894
11th to 20thNight
32%312%28%23%1
1980
21st to endNight
43%311%23%20%1
1980
October1st to 10thNight
39%412%24%19%1
2096
11th to 20thNight
52%29%23%13%1
2160
21st to endNight
56%28%21%10%2
2377
November1st to 10thNight
46%211%23%15%3
2406
11th to 20thNight
58%28%19%10%2
2485
21st to endNight
62%211%18%6%
2660
December1st to 10thNight
69%29%14%6%
2660
11th to 20thNight
67%211%17%3
3288
21st to endNight
78%29%9%2
4720

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%22%31%10%41
270
11th to 20thDay
30%24%34%9%3
270
21st to endDay
31%30%26%10%2
282
February1st to 10thDay
37%23%34%7%
240
11th to 20thDay
30%30%33%6%1
240
21st to endDay
34%29%31%6%
198
March1st to 10thDay
28%22%32%15%4
370
11th to 20thDay
31%16%33%14%5%1
420
21st to endDay
32%20%26%16%5%
462
April1st to 10thDay
25%21%30%16%7%1
420
11th to 20thDay
28%18%25%16%8%4
412
21st to endDay
27%18%29%18%6%2
420
May1st to 10thDay
29%14%30%16%8%3
423
11th to 20thDay
24%12%33%19%8%4
447
21st to endDay
16%10%27%24%17%5%
485
June1st to 10thDay
17%10%34%26%10%3
450
11th to 20thDay
19%9%24%31%12%5%
450
21st to endDay
15%9%32%28%11%5%
450
July1st to 10thDay
12%323%29%24%9%
445
11th to 20thDay
15%327%29%20%7%
444
21st to endDay
13%6%25%29%20%8%
488
August1st to 10thDay
15%420%29%22%10%
446
11th to 20thDay
17%6%23%26%19%10%
439
21st to endDay
12%5%22%29%21%12%
495
September1st to 10thDay
19%6%20%28%18%9%
450
11th to 20thDay
13%420%26%27%10%
450
21st to endDay
25%8%23%23%16%5%
450
October1st to 10thDay
16%8%30%25%17%4
450
11th to 20thDay
24%16%35%16%8%1
450
21st to endDay
34%15%29%19%3
491
November1st to 10thDay
22%22%31%13%11%1
270
11th to 20thDay
36%20%25%15%31
261
21st to endDay
26%23%41%8%1
180
December1st to 10thDay
29%22%33%11%32
180
11th to 20thDay
27%28%33%10%2
180
21st to endDay
35%22%31%10%1
243
January1st to 10thNight
29%20%32%15%4
760
11th to 20thNight
36%18%27%16%3
760
21st to endNight
28%20%29%21%3
820
February1st to 10thNight
30%17%32%18%3
720
11th to 20thNight
27%20%32%18%2
703
21st to endNight
30%20%34%15%2
592
March1st to 10thNight
25%16%34%21%4
720
11th to 20thNight
24%16%30%23%6%1
720
21st to endNight
24%13%30%24%7%1
792
April1st to 10thNight
24%14%31%24%5%1
720
11th to 20thNight
24%11%33%21%10%1
577
21st to endNight
19%10%36%27%7%1
540
May1st to 10thNight
21%10%27%31%9%1
540
11th to 20thNight
21%6%26%36%10%1
531
21st to endNight
13%325%37%20%2
562
June1st to 10thNight
12%432%37%15%1
360
11th to 20thNight
13%427%43%13%
360
21st to endNight
13%426%38%18%1
378
July1st to 10thNight
11%114%42%28%3
525
11th to 20thNight
10%220%40%25%4
522
21st to endNight
10%315%43%25%2
591
August1st to 10thNight
9%215%43%28%4
537
11th to 20thNight
14%113%39%31%3
534
21st to endNight
12%119%33%31%3
614
September1st to 10thNight
15%418%32%27%5%
720
11th to 20thNight
11%317%35%31%4
720
21st to endNight
18%6%23%30%19%5%
720
October1st to 10thNight
17%7%25%30%20%3
720
11th to 20thNight
25%10%28%27%8%2
720
21st to endNight
28%12%29%24%6%
792
November1st to 10thNight
21%13%28%26%12%1
740
11th to 20thNight
27%17%29%19%7%1
760
21st to endNight
30%17%29%17%7%
760
December1st to 10thNight
33%17%29%16%5%
760
11th to 20thNight
28%19%32%18%3
760
21st to endNight
32%16%30%20%2
836
Page generated at 2024-01-24 09:37:29. Version ac07

Copyright 2024 Attilla Danko


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