Sandusky
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Sandusky clear sky chart from 2005-11-06 to 2024-01-22.

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%
24104
9%
74893
7%
24053
43%
24053
11%
60656

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
17%
936
5%
2637
1%
935
21%
935
6%
2329
January11th to 20thNight
16%
760
4%
2470
2%
760
18%
760
4%
2212
January21st to endNight
22%
800
5%
2599
3%
800
25%
800
5%
2268
February1st to 10thNight
22%
720
5%
2340
2%
720
25%
720
7%
1992
February11th to 20thNight
24%
701
7%
2161
3%
700
27%
700
7%
1845
February21st to endNight
22%
592
9%
1776
3%
592
27%
592
8%
1504
March1st to 10thNight
31%
720
10%
2084
7%
720
34%
720
11%
1691
March11th to 20thNight
34%
720
12%
1980
7%
720
39%
720
12%
1598
March21st to endNight
37%
792
10%
2178
7%
792
40%
792
11%
1796
April1st to 10thNight
37%
684
10%
1944
6%
684
40%
684
13%
1566
April11th to 20thNight
42%
533
16%
1611
10%
533
46%
533
14%
1252
April21st to endNight
43%
540
11%
1620
5%
540
47%
540
12%
1293
May1st to 10thNight
44%
540
7%
1620
5%
540
45%
540
9%
1332
May11th to 20thNight
48%
531
13%
1592
11%
531
50%
531
14%
1245
May21st to endNight
64%
582
11%
1745
10%
582
65%
582
16%
1318
June1st to 10thNight
60%
540
9%
1618
9%
540
61%
540
16%
1209
June11th to 20thNight
61%
540
13%
1440
10%
540
64%
540
19%
1072
June21st to endNight
62%
540
14%
1440
11%
540
65%
540
18%
1095
July1st to 10thNight
67%
525
12%
1400
11%
525
68%
525
18%
1061
July11th to 20thNight
68%
522
12%
1491
13%
522
69%
522
18%
1104
July21st to endNight
71%
591
12%
1672
11%
558
72%
558
18%
1237
August1st to 10thNight
70%
537
13%
1600
11%
534
71%
534
18%
1168
August11th to 20thNight
67%
534
16%
1598
13%
534
69%
534
19%
1165
August21st to endNight
67%
594
15%
1782
13%
594
68%
594
18%
1297
September1st to 10thNight
60%
688
14%
1939
10%
688
62%
688
17%
1458
September11th to 20thNight
63%
720
18%
1980
13%
720
66%
720
18%
1489
September21st to endNight
52%
720
11%
1980
9%
720
54%
720
14%
1562
October1st to 10thNight
52%
720
13%
2051
11%
720
54%
720
15%
1576
October11th to 20thNight
35%
720
9%
2160
6%
720
39%
720
10%
1742
October21st to endNight
29%
792
11%
2452
8%
792
33%
792
9%
2008
November1st to 10thNight
39%
740
12%
2406
12%
740
41%
740
13%
1825
November11th to 20thNight
25%
760
11%
2470
8%
760
29%
760
7%
2038
November21st to endNight
26%
760
7%
2546
7%
760
27%
760
7%
2169
December1st to 10thNight
19%
760
3%
2660
2%
760
20%
760
4%
2368
December11th to 20thNight
20%
759
6%
3238
3%
759
25%
759
5%
2638
December21st to endNight
19%
891
1%
4613
1%
878
20%
878
2%
4134

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
14%9%47%6%35%5%5%7%34%
74775
Night
16%10%47%6%35%5%5%7%33%
75123
TransparencyDay
32%38%8%13%8%1
74487
Night
34%38%8%12%7%1
74931
SeeingDay
17%5%19%30%22%7%
14100
Night
20%7%23%30%17%3
24118

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%12%8%13%9%45%445%17%
1518
11th to 20thDay
18%16%8%13%9%45%45%5%14%
1710
21st to endDay
15%17%9%11%10%45%35%5%16%
1791
February1st to 10thDay
17%15%6%9%8%45%5%45%21%
1620
11th to 20thDay
15%11%6%11%9%46%6%5%5%23%
1683
21st to endDay
18%12%410%7%45%5%5%6%25%
1480
March1st to 10thDay
18%11%5%8%6%445%5%6%28%
1876
11th to 20thDay
15%11%47%7%45%45%7%32%
1980
21st to endDay
20%11%49%7%3435%6%27%
2178
April1st to 10thDay
13%10%5%8%7%45%5%5%6%32%
2032
11th to 20thDay
17%8%36%6%35%5%5%7%35%
2297
21st to endDay
19%9%46%5%34447%35%
2340
May1st to 10thDay
16%7%47%7%45%5%5%7%34%
2340
11th to 20thDay
16%8%36%6%35%6%6%6%34%
2301
21st to endDay
9%6%35%6%35%6%6%8%42%
2531
June1st to 10thDay
12%5%35%6%45%6%6%8%40%
2340
11th to 20thDay
10%5%245%36%6%6%8%43%
2517
21st to endDay
10%425%5%36%5%7%10%41%
2520
July1st to 10thDay
9%5%25%5%35%5%6%8%47%
2520
11th to 20thDay
9%4245%35%5%7%10%46%
2417
21st to endDay
7%5%35%5%36%5%6%10%44%
2547
August1st to 10thDay
8%5%24436%5%6%10%47%
2327
11th to 20thDay
9%5%25%5%45%6%7%10%42%
2303
21st to endDay
11%435%5%35%5%6%9%44%
2574
September1st to 10thDay
14%5%25%4346%5%7%44%
1999
11th to 20thDay
11%5%26%5%36%5%6%9%43%
1980
21st to endDay
17%6%25%5%35%45%7%41%
1980
October1st to 10thDay
13%8%36%5%3445%8%41%
1908
11th to 20thDay
17%9%36%6%345%5%6%36%
1800
21st to endDay
20%9%37%6%36%5%5%7%28%
1901
November1st to 10thDay
11%9%47%6%445%6%8%38%
1672
11th to 20thDay
16%14%5%7%6%35%445%32%
1710
21st to endDay
18%14%6%9%6%35%5%6%7%23%
1629
December1st to 10thDay
16%18%7%10%8%35%5%45%18%
1520
11th to 20thDay
16%14%5%12%7%45%5%5%7%19%
1919
21st to endDay
24%19%8%11%8%34435%11%
3015
January1st to 10thNight
19%14%6%10%6%35%45%6%23%
2637
11th to 20thNight
19%17%7%12%7%45%5%45%17%
2470
21st to endNight
16%17%7%11%7%45%435%22%
2599
February1st to 10thNight
20%12%5%10%8%45%45%5%23%
2340
11th to 20thNight
16%14%6%11%6%35%5%45%24%
2159
21st to endNight
20%12%49%7%44446%27%
1776
March1st to 10thNight
15%11%6%7%6%45%45%6%31%
2084
11th to 20thNight
14%10%45%6%45%5%5%8%35%
1980
21st to endNight
19%10%47%5%33447%33%
2178
April1st to 10thNight
15%11%46%6%345%5%7%34%
1944
11th to 20thNight
15%9%37%5%347%5%7%36%
1611
21st to endNight
16%8%36%7%445%6%7%36%
1620
May1st to 10thNight
17%8%48%6%46%5%48%30%
1620
11th to 20thNight
19%7%35%5%246%6%9%35%
1592
21st to endNight
9%425%5%46%6%7%11%42%
1744
June1st to 10thNight
10%6%36%425%5%6%8%45%
1618
11th to 20thNight
9%6%25%6%346%7%10%42%
1440
21st to endNight
10%4344345%5%12%45%
1440
July1st to 10thNight
8%5%35%5%445%6%9%48%
1440
11th to 20thNight
8%416%425%6%8%9%47%
1540
21st to endNight
6%425%5%35%6%7%10%48%
1771
August1st to 10thNight
6%326%6%345%7%10%48%
1611
11th to 20thNight
9%5%25%5%46%5%7%8%46%
1598
21st to endNight
8%425%5%45%6%6%8%46%
1782
September1st to 10thNight
12%6%25%5%3446%8%46%
1939
11th to 20thNight
10%5%25%5%45%45%7%48%
1980
21st to endNight
13%6%27%5%3445%8%42%
1980
October1st to 10thNight
13%6%36%5%245%5%8%43%
2051
11th to 20thNight
19%9%26%6%34447%35%
2160
21st to endNight
23%8%36%6%3445%5%31%
2452
November1st to 10thNight
14%9%47%5%35%45%6%37%
2406
11th to 20thNight
16%11%5%8%6%35%5%5%7%28%
2470
21st to endNight
21%12%6%7%6%35%45%6%24%
2546
December1st to 10thNight
18%16%6%10%7%4445%5%21%
2660
11th to 20thNight
17%15%6%8%5%245%5%7%24%
3253
21st to endNight
26%19%7%9%7%34446%12%
4632

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
45%41%7%7%1
1519
11th to 20thDay
46%41%6%6%1
1710
21st to endDay
48%39%5%6%2
1791
February1st to 10thDay
41%38%8%8%4
1620
11th to 20thDay
42%38%7%8%41
1692
21st to endDay
40%37%8%10%41
1480
March1st to 10thDay
35%39%8%14%4
1876
11th to 20thDay
36%38%7%12%6%1
1980
21st to endDay
39%38%6%13%3
2178
April1st to 10thDay
31%39%8%13%9%1
2032
11th to 20thDay
34%36%7%12%10%1
2297
21st to endDay
32%38%7%15%7%1
2340
May1st to 10thDay
32%39%7%13%9%1
2340
11th to 20thDay
30%38%8%11%11%2
2305
21st to endDay
24%40%9%17%8%1
2531
June1st to 10thDay
25%40%7%17%8%2
2340
11th to 20thDay
20%40%11%16%11%2
2517
21st to endDay
25%39%8%14%11%3
2520
July1st to 10thDay
21%40%7%17%13%2
2451
11th to 20thDay
20%41%9%18%11%1
2343
21st to endDay
23%40%10%16%10%1
2405
August1st to 10thDay
22%39%10%20%9%
2314
11th to 20thDay
22%39%10%17%9%2
2303
21st to endDay
22%39%7%16%13%3
2574
September1st to 10thDay
25%38%9%14%11%2
1999
11th to 20thDay
23%39%9%17%11%1
1980
21st to endDay
31%38%9%11%11%
1980
October1st to 10thDay
27%38%7%18%9%1
1908
11th to 20thDay
35%37%8%13%6%1
1800
21st to endDay
35%39%8%11%7%1
1901
November1st to 10thDay
24%42%7%16%11%
1672
11th to 20thDay
34%39%7%12%7%
1710
21st to endDay
35%41%8%12%4
1629
December1st to 10thDay
42%42%8%7%2
1520
11th to 20thDay
44%35%8%11%2
1915
21st to endDay
63%27%6%31
3015
January1st to 10thNight
42%40%6%9%3
2637
11th to 20thNight
44%40%7%6%1
2470
21st to endNight
44%38%8%8%2
2599
February1st to 10thNight
41%38%8%11%3
2340
11th to 20thNight
41%37%8%9%4
2161
21st to endNight
41%36%7%10%41
1776
March1st to 10thNight
34%37%8%14%6%
2084
11th to 20thNight
33%37%7%13%9%1
1980
21st to endNight
35%37%7%15%5%1
2178
April1st to 10thNight
32%38%6%11%11%2
1944
11th to 20thNight
28%38%8%12%12%2
1611
21st to endNight
32%38%6%13%10%2
1620
May1st to 10thNight
37%37%7%10%7%2
1620
11th to 20thNight
28%38%7%11%13%3
1593
21st to endNight
24%39%8%18%9%2
1745
June1st to 10thNight
24%38%9%16%10%3
1618
11th to 20thNight
20%40%12%15%11%2
1440
21st to endNight
23%39%8%17%12%1
1440
July1st to 10thNight
23%39%6%16%14%3
1400
11th to 20thNight
20%40%9%18%12%1
1491
21st to endNight
19%41%11%14%12%2
1672
August1st to 10thNight
22%38%11%19%9%1
1600
11th to 20thNight
21%38%9%19%11%2
1598
21st to endNight
21%38%8%15%15%3
1782
September1st to 10thNight
25%37%8%16%11%3
1939
11th to 20thNight
24%37%8%17%14%
1980
21st to endNight
29%38%9%13%11%1
1980
October1st to 10thNight
26%38%7%15%12%1
2051
11th to 20thNight
34%37%8%12%8%
2160
21st to endNight
36%38%6%13%6%1
2452
November1st to 10thNight
24%41%9%15%10%1
2406
11th to 20thNight
35%40%8%10%6%1
2470
21st to endNight
38%41%7%11%3
2546
December1st to 10thNight
43%41%6%7%2
2660
11th to 20thNight
42%35%11%10%2
3256
21st to endNight
60%27%8%41
4632

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
24%10%27%29%9%1
270
11th to 20thDay
24%9%37%22%7%
270
21st to endDay
24%7%33%25%10%1
267
February1st to 10thDay
26%7%30%33%5%
240
11th to 20thDay
23%8%37%26%6%
240
21st to endDay
22%7%40%27%5%
198
March1st to 10thDay
21%6%28%34%11%
316
11th to 20thDay
19%7%31%32%10%2
420
21st to endDay
25%6%27%32%9%1
462
April1st to 10thDay
16%5%26%38%13%2
420
11th to 20thDay
20%5%25%32%12%5%
412
21st to endDay
22%5%25%30%16%2
420
May1st to 10thDay
21%5%20%32%18%4
423
11th to 20thDay
17%319%32%23%6%
447
21st to endDay
11%212%30%34%11%
485
June1st to 10thDay
12%312%37%30%7%
450
11th to 20thDay
12%313%37%29%7%
627
21st to endDay
11%413%35%30%7%
630
July1st to 10thDay
10%18%29%35%17%
621
11th to 20thDay
9%28%31%36%13%
516
21st to endDay
8%38%33%37%10%
488
August1st to 10thDay
11%16%28%38%15%
446
11th to 20thDay
10%38%33%35%12%
439
21st to endDay
9%47%32%35%14%
495
September1st to 10thDay
14%210%23%35%14%
450
11th to 20thDay
11%38%24%36%17%
450
21st to endDay
19%6%16%22%27%10%
450
October1st to 10thDay
13%5%16%26%27%12%
450
11th to 20thDay
21%7%22%32%15%3
450
21st to endDay
27%10%25%25%11%2
416
November1st to 10thDay
12%9%25%28%20%6%
270
11th to 20thDay
23%15%23%26%11%2
270
21st to endDay
26%6%31%31%6%
231
December1st to 10thDay
19%12%34%26%9%1
180
11th to 20thDay
19%11%40%23%7%
184
21st to endDay
26%10%30%28%7%
297
January1st to 10thNight
26%11%35%21%7%
939
11th to 20thNight
28%11%31%24%6%
760
21st to endNight
25%9%31%28%6%1
800
February1st to 10thNight
24%8%34%28%5%
720
11th to 20thNight
23%8%34%31%5%
703
21st to endNight
27%8%36%26%4
592
March1st to 10thNight
21%5%33%32%9%
720
11th to 20thNight
18%6%34%31%9%2
720
21st to endNight
22%6%26%32%12%1
792
April1st to 10thNight
20%8%27%33%11%1
684
11th to 20thNight
18%7%25%35%13%3
533
21st to endNight
21%324%35%15%2
540
May1st to 10thNight
20%5%18%38%16%3
540
11th to 20thNight
23%415%31%22%4
531
21st to endNight
11%212%32%34%10%
584
June1st to 10thNight
13%314%38%29%4
540
11th to 20thNight
10%215%39%30%4
540
21st to endNight
10%216%36%31%4
540
July1st to 10thNight
10%38%34%35%10%
525
11th to 20thNight
9%212%34%34%8%
522
21st to endNight
9%29%38%38%4
591
August1st to 10thNight
9%27%39%33%9%
537
11th to 20thNight
11%110%33%35%10%
534
21st to endNight
10%312%29%37%9%
594
September1st to 10thNight
14%411%30%32%9%
688
11th to 20thNight
12%312%29%34%10%
720
21st to endNight
15%6%16%31%24%7%
720
October1st to 10thNight
17%5%18%29%23%7%
720
11th to 20thNight
27%9%24%27%12%2
720
21st to endNight
29%10%24%27%8%1
792
November1st to 10thNight
20%10%25%29%14%2
740
11th to 20thNight
25%13%31%22%8%2
760
21st to endNight
29%11%28%25%7%
760
December1st to 10thNight
27%13%31%23%7%
760
11th to 20thNight
26%11%35%23%5%1
760
21st to endNight
30%12%28%25%5%
897
Page generated at 2024-01-19 09:28:36. Version ac07

Copyright 2024 Attilla Danko


Sandusky Clear Sky Chart |Charts Home