South Haven Pier
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the South Haven Pier clear sky chart from 2005-11-06 to 2024-01-12.

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
30%
24594
14%
74700
9%
24536
35%
24536
17%
54492

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
12%
950
7%
2648
2%
946
16%
946
7%
2292
January11th to 20thNight
10%
910
5%
2547
2%
910
13%
910
6%
2201
January21st to endNight
10%
990
3%
2772
1%
990
12%
990
6%
2449
February1st to 10thNight
11%
766
6%
2274
1%
766
16%
766
6%
1936
February11th to 20thNight
14%
700
10%
2099
4%
700
19%
700
8%
1724
February21st to endNight
13%
592
11%
1776
3%
592
21%
592
10%
1392
March1st to 10thNight
24%
720
13%
2160
8%
720
28%
720
15%
1582
March11th to 20thNight
25%
720
20%
2062
8%
720
35%
720
21%
1402
March21st to endNight
26%
693
16%
2079
9%
693
33%
693
17%
1496
April1st to 10thNight
25%
540
13%
1800
9%
540
32%
540
16%
1232
April11th to 20thNight
30%
533
19%
1758
12%
533
40%
533
19%
1184
April21st to endNight
32%
540
17%
1620
9%
540
39%
540
21%
1088
May1st to 10thNight
30%
540
14%
1620
8%
540
35%
540
20%
1119
May11th to 20thNight
38%
531
18%
1575
10%
531
46%
531
24%
1038
May21st to endNight
46%
583
15%
1552
10%
582
51%
582
31%
1021
June1st to 10thNight
52%
540
17%
1440
10%
540
58%
540
36%
886
June11th to 20thNight
46%
540
18%
1440
12%
540
52%
540
34%
912
June21st to endNight
52%
540
17%
1440
11%
540
57%
540
32%
924
July1st to 10thNight
61%
525
18%
1400
12%
525
64%
525
41%
815
July11th to 20thNight
58%
522
21%
1392
16%
522
61%
522
39%
823
July21st to endNight
61%
591
21%
1487
15%
558
65%
558
38%
899
August1st to 10thNight
64%
537
21%
1556
18%
534
68%
534
37%
902
August11th to 20thNight
62%
534
22%
1620
18%
534
67%
534
34%
948
August21st to endNight
58%
594
23%
1980
20%
594
63%
594
32%
1117
September1st to 10thNight
54%
540
23%
1800
22%
540
60%
540
29%
1054
September11th to 20thNight
56%
707
30%
1967
22%
707
61%
707
36%
1179
September21st to endNight
43%
720
22%
1980
14%
720
48%
720
27%
1298
October1st to 10thNight
42%
720
23%
1980
15%
720
48%
720
26%
1320
October11th to 20thNight
24%
720
15%
2198
6%
720
34%
720
16%
1568
October21st to endNight
20%
792
14%
2574
7%
792
29%
792
13%
1919
November1st to 10thNight
25%
740
18%
2406
12%
740
33%
740
16%
1679
November11th to 20thNight
15%
760
13%
2470
6%
760
24%
760
10%
1916
November21st to endNight
16%
760
11%
2470
7%
760
23%
760
11%
1918
December1st to 10thNight
9%
912
4%
2622
2%
912
12%
912
6%
2268
December11th to 20thNight
10%
950
5%
3277
1%
949
14%
949
6%
2824
December21st to endNight
7%
1042
3%
4859
0%
1026
12%
1026
3%
4167

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%
74831
Night
16%13%5%8%6%34446%31%
74909
TransparencyDay
50%411%22%11%2
74532
Night
56%310%19%10%1
74729
SeeingDay
20%16%30%21%10%3
14625
Night
22%14%27%25%11%1
24601

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
16%18%9%13%11%43445%14%
1517
11th to 20thDay
16%21%9%15%9%3443312%
1453
21st to endDay
16%22%10%14%10%35%33311%
1584
February1st to 10thDay
15%16%8%15%13%4444314%
1679
11th to 20thDay
14%13%7%17%9%3444420%
1748
21st to endDay
17%13%7%12%7%34446%22%
1480
March1st to 10thDay
14%12%6%9%7%46%35%7%28%
1800
11th to 20thDay
12%10%5%8%6%3446%8%35%
1898
21st to endDay
18%12%48%6%3445%6%30%
2293
April1st to 10thDay
18%12%45%6%35%45%7%30%
2160
11th to 20thDay
16%10%45%4245%5%6%39%
2149
21st to endDay
18%8%36%5%3446%7%35%
2340
May1st to 10thDay
16%7%36%6%45%6%6%6%35%
2340
11th to 20thDay
17%6%37%5%2445%7%40%
2317
21st to endDay
10%5%36%5%35%5%6%9%43%
2725
June1st to 10thDay
11%425%5%345%5%8%48%
2520
11th to 20thDay
9%5%25%43447%8%49%
2520
21st to endDay
12%5%25%5%345%6%8%46%
2520
July1st to 10thDay
7%41433436%11%53%
2520
11th to 20thDay
9%42443446%10%50%
2520
21st to endDay
7%4245%345%6%10%51%
2743
August1st to 10thDay
9%4245%35%5%6%9%48%
2371
11th to 20thDay
9%5%25%5%345%5%8%49%
2278
21st to endDay
10%425%5%3335%9%51%
2376
September1st to 10thDay
11%6%35%5%345%6%8%45%
2154
11th to 20thDay
12%5%2443446%9%47%
1980
21st to endDay
12%7%36%6%345%6%9%41%
1980
October1st to 10thDay
18%7%36%5%34435%43%
1980
11th to 20thDay
26%9%28%6%345%5%7%26%
1757
21st to endDay
27%12%46%6%45%5%45%22%
1782
November1st to 10thDay
16%13%45%5%34446%36%
1672
11th to 20thDay
17%23%6%8%5%345%35%22%
1710
21st to endDay
23%20%6%9%5%2333421%
1710
December1st to 10thDay
16%25%12%10%6%3233415%
1554
11th to 20thDay
14%24%14%11%6%34445%13%
1918
21st to endDay
24%23%9%11%6%2333411%
2783
January1st to 10thNight
18%19%9%14%9%3443414%
2648
11th to 20thNight
18%19%10%13%8%35%33415%
2547
21st to endNight
16%19%12%14%10%45%33411%
2772
February1st to 10thNight
15%18%7%16%11%4333415%
2274
11th to 20thNight
15%16%9%13%9%3434419%
2098
21st to endNight
19%16%6%11%7%32345%24%
1776
March1st to 10thNight
17%10%6%9%6%3345%5%31%
2160
11th to 20thNight
13%9%47%5%34447%39%
2062
21st to endNight
21%9%47%5%245%46%33%
2079
April1st to 10thNight
14%11%46%5%445%5%6%35%
1800
11th to 20thNight
20%10%35%4245%46%37%
1758
21st to endNight
18%8%35%5%3445%8%37%
1620
May1st to 10thNight
16%8%47%7%3445%8%33%
1620
11th to 20thNight
18%6%35%5%335%5%7%40%
1574
21st to endNight
11%6%37%5%35%46%9%42%
1551
June1st to 10thNight
11%425%4245%7%9%47%
1440
11th to 20thNight
9%6%25%5%345%6%8%46%
1440
21st to endNight
10%5%35%5%36%6%5%9%44%
1440
July1st to 10thNight
7%425%5%3445%10%51%
1440
11th to 20thNight
8%3145%245%6%8%52%
1440
21st to endNight
7%4236%35%5%6%10%48%
1575
August1st to 10thNight
8%3245%45%6%6%9%48%
1565
11th to 20thNight
10%4245%35%45%8%49%
1620
21st to endNight
9%6%25%5%34447%51%
1980
September1st to 10thNight
11%5%25%5%2445%7%48%
1800
11th to 20thNight
12%424434447%52%
1967
21st to endNight
13%7%36%5%345%5%7%42%
1980
October1st to 10thNight
18%7%35%43345%5%43%
1980
11th to 20thNight
23%11%45%5%33445%33%
2198
21st to endNight
29%12%35%5%23335%28%
2574
November1st to 10thNight
17%14%5%6%5%23445%35%
2406
11th to 20thNight
18%22%7%8%424445%23%
2470
21st to endNight
20%20%7%7%5%33335%24%
2470
December1st to 10thNight
20%26%10%10%5%2334414%
2622
11th to 20thNight
17%23%12%11%6%2444413%
3279
21st to endNight
27%22%8%8%6%3443411%
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
75%38%11%2
1518
11th to 20thDay
78%311%6%2
1453
21st to endDay
81%27%7%3
1584
February1st to 10thDay
77%38%10%2
1679
11th to 20thDay
69%39%13%5%1
1758
21st to endDay
66%410%14%6%1
1480
March1st to 10thDay
59%313%17%8%
1800
11th to 20thDay
49%412%22%11%2
1898
21st to endDay
56%411%23%6%1
2293
April1st to 10thDay
54%39%21%12%
2160
11th to 20thDay
47%39%24%14%3
2149
21st to endDay
49%412%19%14%2
2340
May1st to 10thDay
48%5%12%24%10%1
2340
11th to 20thDay
45%411%23%16%2
2321
21st to endDay
38%5%13%28%14%2
2725
June1st to 10thDay
35%412%27%20%2
2520
11th to 20thDay
33%5%12%27%21%2
2520
21st to endDay
37%415%24%17%2
2520
July1st to 10thDay
28%313%32%19%4
2451
11th to 20thDay
31%413%31%19%3
2445
21st to endDay
30%5%13%30%19%3
2591
August1st to 10thDay
33%5%14%32%15%2
2356
11th to 20thDay
34%5%15%30%14%2
2278
21st to endDay
32%414%28%19%4
2376
September1st to 10thDay
38%5%13%26%15%4
2154
11th to 20thDay
35%312%34%14%2
1980
21st to endDay
41%310%29%16%1
1980
October1st to 10thDay
46%38%27%14%1
1980
11th to 20thDay
59%311%19%8%
1757
21st to endDay
65%310%15%6%1
1782
November1st to 10thDay
51%412%20%13%1
1672
11th to 20thDay
67%29%16%5%1
1710
21st to endDay
69%311%13%4
1710
December1st to 10thDay
76%38%10%3
1554
11th to 20thDay
76%211%9%1
1915
21st to endDay
81%27%9%1
2783
January1st to 10thNight
77%28%10%2
2648
11th to 20thNight
76%310%8%3
2547
21st to endNight
80%29%6%3
2772
February1st to 10thNight
75%38%10%4
2274
11th to 20thNight
70%36%14%6%
2099
21st to endNight
65%210%15%7%1
1776
March1st to 10thNight
56%411%20%8%1
2160
11th to 20thNight
47%412%22%12%3
2062
21st to endNight
54%49%22%10%1
2079
April1st to 10thNight
50%412%21%13%1
1800
11th to 20thNight
49%37%19%18%3
1758
21st to endNight
47%411%20%15%3
1620
May1st to 10thNight
50%311%23%11%1
1620
11th to 20thNight
45%410%22%16%3
1575
21st to endNight
39%5%13%25%15%2
1552
June1st to 10thNight
34%5%10%31%18%3
1440
11th to 20thNight
37%411%26%19%3
1440
21st to endNight
38%5%15%24%16%3
1440
July1st to 10thNight
30%414%29%19%5%
1400
11th to 20thNight
30%5%12%28%21%4
1392
21st to endNight
32%5%14%25%21%3
1487
August1st to 10thNight
32%5%15%28%19%2
1556
11th to 20thNight
34%413%30%17%2
1620
21st to endNight
34%49%28%21%4
1980
September1st to 10thNight
36%410%28%17%4
1800
11th to 20thNight
35%38%33%19%2
1967
21st to endNight
43%410%26%16%1
1980
October1st to 10thNight
44%47%26%17%2
1980
11th to 20thNight
55%210%21%11%1
2198
21st to endNight
61%310%18%8%1
2574
November1st to 10thNight
53%39%21%13%1
2406
11th to 20thNight
65%210%16%6%1
2470
21st to endNight
66%213%16%3
2470
December1st to 10thNight
77%27%9%4
2622
11th to 20thNight
76%410%8%2
3281
21st to endNight
80%210%7%1
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
23%24%32%16%31
270
11th to 20thDay
24%19%41%13%3
245
21st to endDay
31%21%33%12%2
264
February1st to 10thDay
30%28%27%13%2
240
11th to 20thDay
27%33%31%8%1
240
21st to endDay
32%34%25%8%1
198
March1st to 10thDay
23%38%27%10%3
240
11th to 20thDay
23%22%32%18%41
338
21st to endDay
32%20%28%15%5%1
462
April1st to 10thDay
27%21%32%14%6%
420
11th to 20thDay
26%26%27%13%6%2
412
21st to endDay
27%20%30%15%7%1
420
May1st to 10thDay
25%19%30%18%6%2
423
11th to 20thDay
21%15%33%20%7%4
463
21st to endDay
14%12%35%22%13%4
679
June1st to 10thDay
11%11%38%24%11%4
630
11th to 20thDay
14%12%32%30%10%3
630
21st to endDay
15%10%37%24%12%3
630
July1st to 10thDay
9%7%28%32%17%7%
621
11th to 20thDay
10%9%32%32%12%6%
618
21st to endDay
7%7%33%33%14%5%
684
August1st to 10thDay
10%5%24%30%21%11%
490
11th to 20thDay
12%6%25%27%22%7%
439
21st to endDay
13%8%24%33%17%6%
495
September1st to 10thDay
15%8%24%31%15%6%
450
11th to 20thDay
11%7%23%27%23%8%
450
21st to endDay
17%16%22%23%16%6%
450
October1st to 10thDay
21%12%28%22%14%3
450
11th to 20thDay
32%22%27%16%3
330
21st to endDay
39%19%30%9%3
297
November1st to 10thDay
27%21%31%16%5%1
270
11th to 20thDay
30%26%28%13%3
270
21st to endDay
33%25%31%10%
270
December1st to 10thDay
31%30%24%11%4
270
11th to 20thDay
26%29%30%13%21
270
21st to endDay
29%29%33%8%1
297
January1st to 10thNight
27%23%28%17%4
950
11th to 20thNight
30%18%31%17%41
910
21st to endNight
25%19%32%21%3
990
February1st to 10thNight
25%20%33%18%3
766
11th to 20thNight
24%21%31%18%4
703
21st to endNight
29%21%32%16%2
592
March1st to 10thNight
23%19%27%24%7%1
720
11th to 20thNight
21%16%34%23%6%1
720
21st to endNight
25%14%29%25%7%1
693
April1st to 10thNight
20%18%30%23%7%1
540
11th to 20thNight
25%15%29%24%7%1
533
21st to endNight
22%12%29%28%7%2
540
May1st to 10thNight
19%11%32%28%8%1
540
11th to 20thNight
20%9%25%31%14%
531
21st to endNight
15%5%27%32%20%2
584
June1st to 10thNight
12%5%24%39%18%1
540
11th to 20thNight
12%430%35%18%1
540
21st to endNight
11%7%24%35%22%2
540
July1st to 10thNight
9%320%36%29%4
525
11th to 20thNight
9%5%21%34%27%4
522
21st to endNight
8%419%42%25%2
591
August1st to 10thNight
8%315%43%26%4
537
11th to 20thNight
10%414%39%28%5%
534
21st to endNight
10%6%18%35%27%3
594
September1st to 10thNight
13%6%18%36%23%4
540
11th to 20thNight
14%6%18%32%26%3
707
21st to endNight
18%10%22%26%19%5%
720
October1st to 10thNight
20%10%23%28%17%2
720
11th to 20thNight
29%16%26%22%6%1
720
21st to endNight
36%15%25%19%5%
792
November1st to 10thNight
25%16%29%20%9%1
740
11th to 20thNight
32%21%27%16%31
760
21st to endNight
33%16%31%17%3
760
December1st to 10thNight
33%21%29%14%3
912
11th to 20thNight
30%20%31%15%31
950
21st to endNight
36%20%29%13%1
1045
Page generated at 2024-01-09 16:24:25. Version ac07

Copyright 2024 Attilla Danko


South Haven Pier Clear Sky Chart |Charts Home