Munson Observing Site
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Munson Observing Site clear sky chart from 2005-11-06 to 2024-01-13.

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
51%
23494
22%
74469
16%
23440
58%
23440
28%
44833

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
29%
760
23%
2431
10%
757
44%
757
23%
1504
January11th to 20thNight
37%
732
28%
2196
16%
732
48%
732
26%
1344
January21st to endNight
26%
792
27%
2376
10%
792
41%
792
23%
1540
February1st to 10thNight
29%
720
25%
2160
11%
720
41%
720
26%
1366
February11th to 20thNight
30%
703
23%
2099
9%
700
41%
700
26%
1319
February21st to endNight
26%
592
22%
1776
10%
592
36%
592
21%
1198
March1st to 10thNight
34%
720
25%
2160
13%
720
44%
720
29%
1293
March11th to 20thNight
34%
720
21%
2062
11%
720
42%
720
27%
1315
March21st to endNight
39%
707
26%
2093
13%
707
49%
707
30%
1238
April1st to 10thNight
43%
540
25%
1800
19%
540
52%
540
26%
1076
April11th to 20thNight
43%
533
25%
1775
18%
533
54%
533
29%
1033
April21st to endNight
56%
540
31%
1800
26%
540
66%
540
42%
884
May1st to 10thNight
58%
540
25%
1756
21%
540
66%
540
38%
944
May11th to 20thNight
64%
531
18%
1592
15%
531
68%
531
34%
955
May21st to endNight
69%
582
22%
1744
20%
582
70%
582
35%
1014
June1st to 10thNight
65%
540
15%
1620
15%
540
66%
540
29%
1027
June11th to 20thNight
78%
540
17%
1620
16%
540
79%
540
35%
959
June21st to endNight
73%
540
13%
1620
11%
540
74%
540
29%
1029
July1st to 10thNight
76%
525
11%
1575
11%
525
76%
525
24%
1052
July11th to 20thNight
78%
522
10%
1587
12%
522
78%
522
27%
1036
July21st to endNight
83%
591
12%
1858
14%
558
84%
558
31%
1089
August1st to 10thNight
82%
537
10%
1778
13%
534
82%
534
29%
1072
August11th to 20thNight
76%
534
10%
1776
12%
534
76%
534
24%
1170
August21st to endNight
68%
594
16%
1980
19%
594
68%
594
20%
1354
September1st to 10thNight
70%
580
17%
1840
18%
580
71%
580
27%
1162
September11th to 20thNight
60%
720
19%
1980
14%
720
62%
720
29%
1282
September21st to endNight
63%
720
28%
1980
22%
720
67%
720
36%
1192
October1st to 10thNight
57%
720
29%
1980
19%
720
64%
720
42%
1114
October11th to 20thNight
61%
720
39%
1980
28%
720
70%
720
47%
1060
October21st to endNight
51%
792
32%
2357
26%
792
59%
792
36%
1314
November1st to 10thNight
53%
740
30%
2406
26%
740
63%
740
39%
1247
November11th to 20thNight
44%
760
31%
2470
23%
760
57%
760
33%
1349
November21st to endNight
42%
760
27%
2470
19%
760
54%
760
30%
1422
December1st to 10thNight
39%
760
26%
2470
18%
760
52%
760
27%
1479
December11th to 20thNight
36%
759
24%
2908
16%
758
46%
758
21%
1739
December21st to endNight
30%
828
15%
4394
13%
817
41%
817
13%
2662

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
10%6%36%6%46%6%6%8%41%
74788
Night
10%5%25%5%345%6%8%46%
74961
TransparencyDay
40%7%12%17%17%8%
74523
Night
35%7%13%18%19%9%
74745
SeeingDay
13%10%22%24%20%12%
13490
Night
13%8%22%29%23%6%
23505

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
14%7%25%5%3445%8%43%
1729
11th to 20thDay
13%5%25%435%446%48%
1826
21st to endDay
17%7%35%434446%43%
1980
February1st to 10thDay
17%6%36%5%345%36%42%
1800
11th to 20thDay
14%6%35%4345%5%7%44%
1748
21st to endDay
15%7%26%5%45%5%5%7%37%
1480
March1st to 10thDay
11%6%26%5%345%5%8%47%
1800
11th to 20thDay
13%6%26%6%345%5%7%43%
1898
21st to endDay
11%5%25%5%35%45%8%47%
2276
April1st to 10thDay
12%6%35%5%245%5%7%47%
2160
11th to 20thDay
13%5%25%6%45%447%44%
2134
21st to endDay
7%4245%45%45%7%53%
2160
May1st to 10thDay
8%4245%345%6%9%50%
2200
11th to 20thDay
6%426%7%47%7%8%9%41%
2301
21st to endDay
6%5%36%7%47%6%7%9%39%
2531
June1st to 10thDay
8%6%47%8%5%8%7%8%11%28%
2340
11th to 20thDay
6%326%7%48%8%9%11%36%
2340
21st to endDay
6%5%27%8%5%9%9%8%10%29%
2340
July1st to 10thDay
9%6%39%7%6%9%9%9%10%23%
2340
11th to 20thDay
7%7%48%9%6%9%8%9%10%23%
2314
21st to endDay
7%5%37%9%6%8%8%9%10%27%
2350
August1st to 10thDay
7%6%37%8%6%8%8%10%10%28%
2148
11th to 20thDay
9%7%27%8%6%8%8%8%11%26%
2125
21st to endDay
12%7%38%8%5%7%6%7%8%29%
2376
September1st to 10thDay
8%5%38%7%5%8%8%8%8%32%
2101
11th to 20thDay
11%6%47%8%46%6%5%7%36%
1980
21st to endDay
8%5%346%46%5%5%7%47%
1980
October1st to 10thDay
7%5%25%5%3445%6%53%
1980
11th to 20thDay
10%42343436%7%55%
1980
21st to endDay
9%5%35%434346%55%
1992
November1st to 10thDay
8%5%2333446%7%57%
1672
11th to 20thDay
9%42433435%8%53%
1710
21st to endDay
13%425%5%345%5%8%47%
1710
December1st to 10thDay
13%6%35%5%245%47%47%
1710
11th to 20thDay
14%9%36%5%34436%42%
2153
21st to endDay
19%8%36%424345%41%
3124
January1st to 10thNight
15%6%26%5%25%446%45%
2431
11th to 20thNight
12%8%35%42446%6%46%
2196
21st to endNight
18%7%35%5%24445%44%
2376
February1st to 10thNight
14%7%35%5%3345%7%44%
2160
11th to 20thNight
16%8%25%423346%46%
2098
21st to endNight
15%10%36%5%35%45%5%39%
1776
March1st to 10thNight
12%5%35%42445%7%48%
2160
11th to 20thNight
12%6%36%4345%5%8%44%
2062
21st to endNight
11%426%5%34448%50%
2093
April1st to 10thNight
11%6%25%5%3445%8%46%
1800
11th to 20thNight
13%5%35%3245%5%7%47%
1775
21st to endNight
5%32443435%7%61%
1800
May1st to 10thNight
9%4234345%5%8%54%
1756
11th to 20thNight
6%5%25%5%35%5%8%10%46%
1592
21st to endNight
6%4246%25%5%7%11%48%
1744
June1st to 10thNight
8%426%5%35%6%8%13%39%
1620
11th to 20thNight
43145%35%9%9%13%44%
1620
21st to endNight
5%426%6%46%7%8%14%38%
1620
July1st to 10thNight
5%435%7%46%8%10%12%37%
1620
11th to 20thNight
5%4346%47%7%9%16%36%
1641
21st to endNight
3225%5%46%8%9%14%41%
1968
August1st to 10thNight
4324436%7%10%13%44%
1790
11th to 20thNight
5%426%6%48%9%8%14%34%
1776
21st to endNight
7%7%36%7%5%7%7%6%10%34%
1980
September1st to 10thNight
8%5%26%6%36%7%7%12%38%
1840
11th to 20thNight
10%436%6%35%7%6%9%41%
1980
21st to endNight
7%5%25%6%345%6%7%50%
1980
October1st to 10thNight
6%5%244245%6%8%54%
1980
11th to 20thNight
6%5%2332345%7%61%
1980
21st to endNight
10%5%24433446%55%
2357
November1st to 10thNight
8%424423447%59%
2406
11th to 20thNight
11%424424446%55%
2470
21st to endNight
13%6%244345%5%7%49%
2470
December1st to 10thNight
14%5%35%6%3435%7%46%
2470
11th to 20thNight
15%7%35%434446%45%
3042
21st to endNight
16%9%46%5%33445%41%
4532

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
41%46%15%24%10%
1730
11th to 20thDay
37%5%7%17%24%10%
1826
21st to endDay
42%45%15%23%11%
1980
February1st to 10thDay
44%47%16%19%10%
1800
11th to 20thDay
40%45%17%22%11%
1758
21st to endDay
45%6%7%16%16%11%
1480
March1st to 10thDay
36%48%19%22%11%
1800
11th to 20thDay
40%5%12%17%17%10%
1898
21st to endDay
36%5%11%19%20%9%
2276
April1st to 10thDay
38%5%10%17%21%11%
2160
11th to 20thDay
40%48%18%21%10%
2134
21st to endDay
30%410%21%24%10%
2160
May1st to 10thDay
30%5%11%21%23%10%
2200
11th to 20thDay
35%9%16%19%18%3
2305
21st to endDay
37%8%12%20%19%3
2531
June1st to 10thDay
46%8%15%21%8%1
2340
11th to 20thDay
36%11%18%23%10%2
2340
21st to endDay
44%11%19%15%9%2
2340
July1st to 10thDay
49%14%20%13%4
2275
11th to 20thDay
48%14%20%13%31
2245
21st to endDay
44%12%22%17%5%
2219
August1st to 10thDay
44%12%23%16%4
2136
11th to 20thDay
48%12%22%13%6%
2125
21st to endDay
50%9%16%14%9%2
2376
September1st to 10thDay
45%9%17%13%12%5%
2101
11th to 20thDay
47%7%12%16%12%7%
1980
21st to endDay
36%6%10%18%21%9%
1980
October1st to 10thDay
32%5%11%19%21%13%
1980
11th to 20thDay
28%48%20%26%14%
1980
21st to endDay
32%4413%26%20%
1992
November1st to 10thDay
28%38%20%24%17%
1672
11th to 20thDay
30%48%17%27%15%
1710
21st to endDay
35%47%19%22%13%
1710
December1st to 10thDay
39%411%18%20%9%
1710
11th to 20thDay
45%45%16%20%10%
2150
21st to endDay
46%3419%21%7%
3124
January1st to 10thNight
41%46%13%25%11%
2431
11th to 20thNight
38%46%17%24%11%
2196
21st to endNight
44%35%12%26%9%
2376
February1st to 10thNight
41%36%18%21%11%
2160
11th to 20thNight
41%37%13%21%14%
2099
21st to endNight
46%5%7%15%14%13%
1776
March1st to 10thNight
36%5%9%18%22%12%
2160
11th to 20thNight
38%5%12%18%17%10%
2062
21st to endNight
34%5%11%20%20%10%
2093
April1st to 10thNight
37%5%12%14%20%12%
1800
11th to 20thNight
35%5%9%20%21%9%
1775
21st to endNight
24%411%27%25%9%
1800
May1st to 10thNight
28%5%12%21%26%9%
1756
11th to 20thNight
30%9%19%18%20%4
1593
21st to endNight
29%8%17%23%18%4
1745
June1st to 10thNight
35%10%21%24%10%1
1620
11th to 20thNight
26%12%25%24%10%2
1620
21st to endNight
32%12%27%18%9%1
1620
July1st to 10thNight
34%16%25%19%5%
1575
11th to 20thNight
30%17%33%16%4
1587
21st to endNight
26%14%34%22%4
1858
August1st to 10thNight
27%16%32%21%41
1778
11th to 20thNight
35%15%29%15%6%
1776
21st to endNight
41%13%18%17%8%3
1980
September1st to 10thNight
34%11%22%16%12%4
1840
11th to 20thNight
37%9%17%18%14%6%
1980
21st to endNight
31%7%14%19%20%9%
1980
October1st to 10thNight
26%6%12%18%23%14%
1980
11th to 20thNight
23%49%21%29%13%
1980
21st to endNight
31%35%16%26%19%
2357
November1st to 10thNight
26%47%19%26%18%
2406
11th to 20thNight
31%45%17%29%14%
2470
21st to endNight
35%49%18%20%14%
2470
December1st to 10thNight
38%49%19%23%8%
2470
11th to 20thNight
41%37%13%25%11%
3044
21st to endNight
47%36%18%21%5%
4532

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
20%21%39%16%31
270
11th to 20thDay
17%21%32%20%9%1
248
21st to endDay
22%28%37%9%3
264
February1st to 10thDay
25%26%29%17%3
240
11th to 20thDay
23%24%34%17%2
240
21st to endDay
17%31%37%14%2
198
March1st to 10thDay
15%25%42%13%5%
240
11th to 20thDay
20%22%30%19%8%1
338
21st to endDay
17%17%33%21%11%1
462
April1st to 10thDay
19%15%32%20%10%3
420
11th to 20thDay
17%15%33%22%11%2
412
21st to endDay
10%13%29%28%16%4
420
May1st to 10thDay
11%11%24%27%20%7%
423
11th to 20thDay
7%426%30%20%14%
447
21st to endDay
9%219%32%20%18%
485
June1st to 10thDay
12%214%32%25%16%
450
11th to 20thDay
8%411%31%25%21%
450
21st to endDay
8%214%25%27%24%
450
July1st to 10thDay
9%27%19%33%29%
445
11th to 20thDay
6%25%20%37%30%
444
21st to endDay
6%18%21%37%27%
488
August1st to 10thDay
9%322%31%34%
446
11th to 20thDay
10%2320%34%31%
439
21st to endDay
12%39%26%32%19%
495
September1st to 10thDay
8%311%26%30%22%
450
11th to 20thDay
14%5%8%31%31%10%
450
21st to endDay
10%316%29%30%12%
450
October1st to 10thDay
10%431%30%19%6%
450
11th to 20thDay
10%7%21%31%24%8%
450
21st to endDay
13%12%24%32%17%2
379
November1st to 10thDay
15%9%29%31%15%2
270
11th to 20thDay
12%15%36%29%8%1
270
21st to endDay
15%15%37%23%10%1
270
December1st to 10thDay
16%20%33%21%8%1
270
11th to 20thDay
24%16%37%18%5%
270
21st to endDay
26%15%34%17%7%1
297
January1st to 10thNight
18%16%33%26%6%
760
11th to 20thNight
17%15%27%32%10%
732
21st to endNight
23%14%33%25%5%
792
February1st to 10thNight
19%13%35%27%6%
720
11th to 20thNight
19%14%33%25%8%
703
21st to endNight
20%13%38%26%3
592
March1st to 10thNight
15%15%33%30%7%
720
11th to 20thNight
14%14%33%27%11%
720
21st to endNight
12%13%31%31%12%1
707
April1st to 10thNight
16%11%26%35%12%1
540
11th to 20thNight
15%10%28%28%19%1
533
21st to endNight
7%6%25%39%21%1
540
May1st to 10thNight
10%6%21%39%21%3
540
11th to 20thNight
8%317%37%30%6%
531
21st to endNight
8%112%34%38%6%
584
June1st to 10thNight
10%210%32%37%10%
540
11th to 20thNight
438%32%42%12%
540
21st to endNight
6%19%23%46%15%
540
July1st to 10thNight
5%1322%48%20%
525
11th to 20thNight
6%1317%42%31%
522
21st to endNight
3325%51%17%
591
August1st to 10thNight
5%1317%49%26%
537
11th to 20thNight
5%2221%46%25%
534
21st to endNight
8%25%23%43%17%
594
September1st to 10thNight
8%37%24%42%16%
580
11th to 20thNight
11%212%29%38%8%
720
21st to endNight
10%215%30%36%7%
720
October1st to 10thNight
8%226%35%26%3
720
11th to 20thNight
9%5%21%33%29%3
720
21st to endNight
13%7%24%32%22%2
792
November1st to 10thNight
10%6%25%37%19%2
740
11th to 20thNight
13%11%28%34%14%1
760
21st to endNight
15%9%29%33%13%1
760
December1st to 10thNight
16%11%29%28%14%1
760
11th to 20thNight
19%10%29%30%12%
760
21st to endNight
25%13%26%26%9%
836
Page generated at 2024-01-10 19:35:19. Version ac07

Copyright 2024 Attilla Danko


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