Muskegon
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Muskegon clear sky chart from 2005-11-06 to 2024-01-15.

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%
24666
13%
74729
9%
24610
37%
24610
17%
54233

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
14%
950
5%
2648
3%
946
16%
946
7%
2292
January11th to 20thNight
13%
921
4%
2577
2%
921
15%
921
6%
2260
January21st to endNight
15%
990
3%
2772
1%
990
16%
990
6%
2448
February1st to 10thNight
13%
792
6%
2326
2%
792
17%
792
7%
1983
February11th to 20thNight
16%
700
9%
2099
4%
700
21%
700
9%
1694
February21st to endNight
16%
592
9%
1776
3%
592
22%
592
11%
1388
March1st to 10thNight
28%
720
14%
2160
8%
720
33%
720
18%
1524
March11th to 20thNight
29%
720
20%
2062
9%
720
37%
720
24%
1359
March21st to endNight
32%
691
17%
2077
11%
691
38%
691
19%
1454
April1st to 10thNight
28%
540
14%
1800
8%
540
36%
540
17%
1231
April11th to 20thNight
30%
533
19%
1744
12%
533
40%
533
18%
1185
April21st to endNight
33%
540
18%
1620
9%
540
41%
540
22%
1079
May1st to 10thNight
36%
540
15%
1620
9%
540
41%
540
22%
1096
May11th to 20thNight
37%
531
19%
1537
10%
531
46%
531
25%
1011
May21st to endNight
46%
583
14%
1552
9%
582
51%
582
28%
1055
June1st to 10thNight
52%
540
17%
1440
11%
540
57%
540
35%
899
June11th to 20thNight
47%
540
17%
1440
11%
540
52%
540
35%
894
June21st to endNight
54%
540
17%
1440
10%
540
59%
540
34%
900
July1st to 10thNight
63%
525
17%
1400
12%
525
66%
525
41%
827
July11th to 20thNight
64%
522
20%
1392
14%
522
67%
522
41%
819
July21st to endNight
61%
591
21%
1487
15%
558
64%
558
38%
895
August1st to 10thNight
62%
537
21%
1530
18%
534
64%
534
38%
884
August11th to 20thNight
66%
534
24%
1598
20%
534
70%
534
38%
910
August21st to endNight
59%
594
22%
1975
20%
594
64%
594
32%
1118
September1st to 10thNight
56%
540
21%
1800
20%
540
61%
540
30%
1047
September11th to 20thNight
57%
704
29%
1964
23%
704
62%
704
39%
1143
September21st to endNight
45%
720
20%
1980
14%
720
49%
720
27%
1311
October1st to 10thNight
45%
720
22%
1980
16%
720
48%
720
29%
1280
October11th to 20thNight
26%
720
12%
2220
6%
720
34%
720
16%
1597
October21st to endNight
23%
792
12%
2574
7%
792
30%
792
15%
1885
November1st to 10thNight
28%
740
17%
2406
12%
740
36%
740
17%
1645
November11th to 20thNight
18%
760
11%
2470
6%
760
24%
760
10%
1931
November21st to endNight
19%
764
9%
2474
5%
764
24%
764
10%
1946
December1st to 10thNight
12%
950
3%
2660
1%
950
13%
950
6%
2306
December11th to 20thNight
15%
950
5%
3271
1%
949
18%
949
6%
2777
December21st to endNight
8%
1040
3%
4858
1%
1026
12%
1026
3%
4160

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%10%47%6%3445%7%35%
74845
Night
16%12%5%8%6%3445%6%31%
74945
TransparencyDay
49%6%12%21%11%1
74546
Night
54%5%12%18%10%1
74765
SeeingDay
18%14%31%23%11%3
14688
Night
20%10%28%28%12%1
24675

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
15%18%8%13%12%5%5%33414%
1517
11th to 20thDay
16%18%10%14%11%3444411%
1472
21st to endDay
14%21%10%16%10%5%432212%
1584
February1st to 10thDay
12%15%8%12%15%5%6%35%414%
1628
11th to 20thDay
13%14%7%14%10%6%5%435%19%
1748
21st to endDay
15%14%8%11%8%5%6%445%20%
1480
March1st to 10thDay
14%11%6%8%7%45%5%6%6%28%
1800
11th to 20thDay
12%9%48%7%445%5%6%37%
1898
21st to endDay
17%10%46%6%446%6%6%31%
2294
April1st to 10thDay
18%10%5%7%6%3445%8%30%
2160
11th to 20thDay
19%8%45%5%35%45%7%36%
2164
21st to endDay
16%8%36%6%4445%8%36%
2340
May1st to 10thDay
15%8%35%5%25%5%6%8%38%
2340
11th to 20thDay
17%6%25%5%3445%7%42%
2355
21st to endDay
11%6%24435%5%6%8%46%
2725
June1st to 10thDay
10%5%345%35%45%8%48%
2520
11th to 20thDay
12%5%2443445%9%49%
2520
21st to endDay
11%5%244445%6%10%46%
2520
July1st to 10thDay
6%42432346%8%58%
2520
11th to 20thDay
8%425%43446%8%53%
2520
21st to endDay
7%4335%35%5%6%8%51%
2743
August1st to 10thDay
8%425%435%5%6%10%48%
2399
11th to 20thDay
10%3245%35%46%8%50%
2303
21st to endDay
10%5%25%5%345%6%8%49%
2377
September1st to 10thDay
11%6%35%5%335%5%8%45%
2156
11th to 20thDay
13%4235%345%5%8%47%
1980
21st to endDay
12%6%36%5%346%6%8%41%
1980
October1st to 10thDay
17%8%36%5%34445%42%
1980
11th to 20thDay
24%9%38%7%45%6%47%23%
1736
21st to endDay
24%12%47%7%35%45%6%23%
1782
November1st to 10thDay
15%14%36%6%35%5%46%33%
1672
11th to 20thDay
17%22%6%9%6%34445%20%
1710
21st to endDay
23%17%6%9%6%33345%19%
1701
December1st to 10thDay
15%23%14%14%5%2333313%
1520
11th to 20thDay
16%22%12%12%8%4443410%
1918
21st to endDay
22%24%8%11%8%333449%
2783
January1st to 10thNight
18%17%10%13%11%4433414%
2648
11th to 20thNight
17%18%9%12%10%35%5%4413%
2577
21st to endNight
14%18%12%13%12%46%335%11%
2772
February1st to 10thNight
13%18%7%14%12%5%5%44415%
2326
11th to 20thNight
15%14%7%12%10%5%5%44420%
2098
21st to endNight
17%16%6%10%8%34445%24%
1776
March1st to 10thNight
16%9%48%6%345%5%6%33%
2160
11th to 20thNight
13%8%36%6%3445%7%40%
2062
21st to endNight
19%8%47%6%3445%7%34%
2077
April1st to 10thNight
17%9%46%6%45%45%7%34%
1800
11th to 20thNight
20%8%36%425%5%5%436%
1744
21st to endNight
17%9%35%5%345%47%39%
1620
May1st to 10thNight
16%7%37%6%35%5%5%8%35%
1620
11th to 20thNight
16%6%35%5%35%5%6%9%38%
1536
21st to endNight
12%8%36%6%35%5%6%7%41%
1551
June1st to 10thNight
12%4244445%8%9%45%
1440
11th to 20thNight
10%5%36%5%2446%9%47%
1440
21st to endNight
10%6%25%5%345%5%9%47%
1440
July1st to 10thNight
7%424335%5%6%10%51%
1440
11th to 20thNight
6%4235%36%5%6%10%50%
1440
21st to endNight
7%5%25%5%245%6%7%52%
1575
August1st to 10thNight
7%424435%5%5%10%50%
1539
11th to 20thNight
8%3245%35%6%6%7%52%
1598
21st to endNight
9%5%35%5%335%5%8%51%
1975
September1st to 10thNight
9%5%35%5%345%5%7%49%
1800
11th to 20thNight
11%424323347%54%
1964
21st to endNight
14%5%37%5%35%45%7%42%
1980
October1st to 10thNight
19%6%25%423346%45%
1980
11th to 20thNight
25%10%46%5%23445%32%
2220
21st to endNight
26%10%37%6%33346%29%
2574
November1st to 10thNight
16%13%36%5%3445%6%35%
2406
11th to 20thNight
18%18%7%10%6%4446%420%
2470
21st to endNight
20%20%5%9%5%33345%22%
2474
December1st to 10thNight
17%22%11%13%6%3333414%
2660
11th to 20thNight
18%21%9%12%7%34445%14%
3279
21st to endNight
26%21%8%9%6%3433412%
4884

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
76%310%9%2
1518
11th to 20thDay
77%5%10%6%2
1472
21st to endDay
81%37%6%3
1584
February1st to 10thDay
73%5%8%13%1
1628
11th to 20thDay
69%49%13%5%
1758
21st to endDay
65%6%11%13%5%
1480
March1st to 10thDay
55%7%13%17%8%1
1800
11th to 20thDay
48%5%13%20%12%2
1898
21st to endDay
51%7%12%20%9%1
2294
April1st to 10thDay
54%5%10%21%10%
2160
11th to 20thDay
48%6%10%19%14%3
2164
21st to endDay
47%5%12%20%13%2
2340
May1st to 10thDay
43%6%12%26%12%1
2340
11th to 20thDay
43%5%13%21%16%2
2359
21st to endDay
36%7%14%28%15%1
2725
June1st to 10thDay
35%6%12%28%17%2
2520
11th to 20thDay
33%6%13%24%22%1
2520
21st to endDay
33%8%15%26%16%2
2520
July1st to 10thDay
25%6%14%34%18%4
2451
11th to 20thDay
28%7%13%30%19%3
2445
21st to endDay
29%8%14%27%19%3
2591
August1st to 10thDay
31%6%14%33%14%2
2384
11th to 20thDay
31%7%15%31%15%2
2303
21st to endDay
31%7%14%27%18%3
2377
September1st to 10thDay
36%7%13%27%14%2
2156
11th to 20thDay
34%6%13%33%12%2
1980
21st to endDay
40%7%13%27%13%
1980
October1st to 10thDay
44%5%9%27%13%1
1980
11th to 20thDay
59%6%13%16%6%
1736
21st to endDay
62%6%12%14%6%
1782
November1st to 10thDay
51%6%13%20%10%
1672
11th to 20thDay
67%312%13%5%
1710
21st to endDay
68%414%12%3
1701
December1st to 10thDay
77%38%9%2
1520
11th to 20thDay
77%412%6%1
1915
21st to endDay
80%48%7%1
2783
January1st to 10thNight
76%310%9%2
2648
11th to 20thNight
76%5%9%7%3
2577
21st to endNight
79%39%7%2
2772
February1st to 10thNight
74%38%11%4
2326
11th to 20thNight
68%39%15%5%
2099
21st to endNight
63%413%12%7%
1776
March1st to 10thNight
51%5%14%21%8%1
2160
11th to 20thNight
44%414%23%13%3
2062
21st to endNight
51%410%22%11%2
2077
April1st to 10thNight
50%5%10%21%13%1
1800
11th to 20thNight
49%47%19%17%3
1744
21st to endNight
45%5%11%22%13%5%
1620
May1st to 10thNight
47%5%13%20%13%2
1620
11th to 20thNight
43%5%11%20%17%4
1537
21st to endNight
42%6%10%25%15%3
1552
June1st to 10thNight
34%6%12%29%16%3
1440
11th to 20thNight
34%5%13%26%20%1
1440
21st to endNight
35%6%15%26%16%3
1440
July1st to 10thNight
28%6%13%28%20%4
1400
11th to 20thNight
29%6%15%28%20%3
1392
21st to endNight
30%7%12%27%20%4
1487
August1st to 10thNight
29%6%16%31%16%2
1530
11th to 20thNight
29%6%14%32%17%2
1598
21st to endNight
32%6%11%28%20%3
1975
September1st to 10thNight
34%6%13%26%18%2
1800
11th to 20thNight
31%412%36%16%1
1964
21st to endNight
42%5%12%28%12%1
1980
October1st to 10thNight
41%410%28%16%1
1980
11th to 20thNight
55%314%19%8%1
2220
21st to endNight
57%414%17%8%
2574
November1st to 10thNight
50%5%12%20%12%1
2406
11th to 20thNight
65%412%13%5%
2470
21st to endNight
66%315%13%2
2474
December1st to 10thNight
76%49%9%3
2660
11th to 20thNight
74%412%7%2
3281
21st to endNight
77%5%11%6%2
4884

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
21%19%36%19%32
270
11th to 20thDay
28%15%37%14%41
252
21st to endDay
24%19%36%16%5%
264
February1st to 10thDay
24%27%33%13%3
240
11th to 20thDay
21%30%36%11%2
240
21st to endDay
30%27%34%7%11
198
March1st to 10thDay
23%32%35%8%2
240
11th to 20thDay
21%19%32%20%9%
338
21st to endDay
29%13%31%20%6%1
462
April1st to 10thDay
26%16%32%19%6%
420
11th to 20thDay
26%26%23%16%7%2
412
21st to endDay
24%16%31%20%8%1
420
May1st to 10thDay
19%19%33%20%7%2
423
11th to 20thDay
20%13%29%25%10%4
501
21st to endDay
15%10%31%26%14%4
679
June1st to 10thDay
10%10%38%28%10%4
630
11th to 20thDay
15%9%32%30%10%4
630
21st to endDay
14%8%37%27%11%4
630
July1st to 10thDay
7%5%29%34%19%7%
621
11th to 20thDay
7%9%30%33%15%6%
618
21st to endDay
8%6%31%31%18%5%
684
August1st to 10thDay
10%5%26%28%23%8%
518
11th to 20thDay
11%421%32%23%9%
439
21st to endDay
13%6%24%32%18%7%
495
September1st to 10thDay
14%8%26%29%18%6%
450
11th to 20thDay
9%6%24%28%26%7%
450
21st to endDay
15%13%23%27%15%6%
450
October1st to 10thDay
20%12%24%24%17%3
450
11th to 20thDay
27%20%30%20%3
320
21st to endDay
35%16%31%13%32
297
November1st to 10thDay
26%18%33%16%42
270
11th to 20thDay
24%24%39%10%3
270
21st to endDay
30%18%38%11%2
270
December1st to 10thDay
29%23%28%16%4
270
11th to 20thDay
26%26%31%14%31
270
21st to endDay
27%25%34%11%2
297
January1st to 10thNight
23%16%32%22%6%
950
11th to 20thNight
26%15%32%22%5%1
921
21st to endNight
22%11%33%28%6%
990
February1st to 10thNight
21%17%34%25%31
792
11th to 20thNight
22%15%33%24%5%
703
21st to endNight
25%18%34%20%3
592
March1st to 10thNight
20%13%31%25%9%1
720
11th to 20thNight
19%12%35%25%9%1
720
21st to endNight
21%10%29%30%10%
691
April1st to 10thNight
19%11%33%29%7%1
540
11th to 20thNight
26%10%30%25%8%1
533
21st to endNight
21%11%31%26%10%1
540
May1st to 10thNight
19%6%32%33%9%1
540
11th to 20thNight
19%7%30%30%13%1
531
21st to endNight
14%5%25%34%20%2
584
June1st to 10thNight
12%5%25%42%15%1
540
11th to 20thNight
13%429%34%19%1
540
21st to endNight
11%5%22%40%21%2
540
July1st to 10thNight
8%118%39%30%4
525
11th to 20thNight
6%321%39%29%2
522
21st to endNight
9%218%41%28%1
591
August1st to 10thNight
8%218%41%28%3
537
11th to 20thNight
11%214%39%29%5%
534
21st to endNight
10%318%41%25%3
594
September1st to 10thNight
11%6%19%38%22%5%
540
11th to 20thNight
12%6%20%32%24%6%
704
21st to endNight
15%9%23%28%19%5%
720
October1st to 10thNight
20%6%23%31%18%1
720
11th to 20thNight
29%11%27%23%9%1
720
21st to endNight
30%10%29%22%7%1
792
November1st to 10thNight
23%12%31%24%10%1
740
11th to 20thNight
28%16%31%20%5%
760
21st to endNight
29%13%30%23%4
764
December1st to 10thNight
27%17%32%20%4
950
11th to 20thNight
28%15%32%20%31
950
21st to endNight
32%14%34%18%2
1045
Page generated at 2024-01-11 22:33:45. Version ac07

Copyright 2024 Attilla Danko


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