Wahnsiedler Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wahnsiedler Observatory 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
45%
24309
21%
74778
15%
24250
51%
24250
26%
48337

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
26%
950
17%
2648
8%
946
34%
946
20%
1861
January11th to 20thNight
21%
950
16%
2660
7%
950
28%
950
18%
1946
January21st to endNight
24%
974
17%
2686
7%
974
32%
974
20%
1927
February1st to 10thNight
23%
720
14%
2160
6%
720
30%
720
16%
1590
February11th to 20thNight
23%
703
18%
2099
8%
700
31%
700
20%
1431
February21st to endNight
20%
592
18%
1776
6%
592
30%
592
18%
1246
March1st to 10thNight
29%
720
19%
2160
10%
720
37%
720
23%
1436
March11th to 20thNight
30%
720
14%
2099
7%
720
36%
720
20%
1466
March21st to endNight
35%
635
15%
2021
10%
635
42%
635
19%
1403
April1st to 10thNight
41%
540
23%
1800
15%
540
52%
540
27%
1088
April11th to 20thNight
40%
533
23%
1775
18%
533
51%
533
26%
1111
April21st to endNight
36%
540
18%
1746
12%
540
44%
540
21%
1156
May1st to 10thNight
43%
540
16%
1620
11%
540
48%
540
24%
1081
May11th to 20thNight
51%
531
17%
1593
12%
531
54%
531
23%
1070
May21st to endNight
63%
582
18%
1684
15%
582
65%
582
30%
1079
June1st to 10thNight
62%
540
22%
1440
17%
540
65%
540
37%
890
June11th to 20thNight
68%
540
24%
1440
19%
540
72%
540
40%
857
June21st to endNight
70%
540
24%
1440
18%
540
72%
540
44%
829
July1st to 10thNight
72%
525
19%
1400
16%
525
73%
525
36%
885
July11th to 20thNight
75%
522
24%
1392
20%
522
76%
522
42%
818
July21st to endNight
72%
591
25%
1543
21%
558
74%
558
38%
919
August1st to 10thNight
75%
537
22%
1664
24%
534
75%
534
37%
929
August11th to 20thNight
74%
534
23%
1776
26%
534
76%
534
32%
1020
August21st to endNight
78%
594
26%
1980
31%
594
79%
594
38%
1052
September1st to 10thNight
69%
540
27%
1800
29%
540
72%
540
34%
1008
September11th to 20thNight
70%
688
30%
1948
26%
688
72%
688
40%
1122
September21st to endNight
58%
720
29%
1980
20%
720
64%
720
37%
1182
October1st to 10thNight
62%
720
31%
1980
23%
720
66%
720
40%
1142
October11th to 20thNight
45%
720
29%
2096
19%
720
55%
720
33%
1258
October21st to endNight
37%
792
23%
2564
17%
792
46%
792
25%
1614
November1st to 10thNight
47%
740
27%
2406
22%
740
57%
740
33%
1356
November11th to 20thNight
37%
760
28%
2470
18%
760
51%
760
28%
1466
November21st to endNight
38%
760
23%
2470
17%
760
47%
760
24%
1578
December1st to 10thNight
31%
760
16%
2470
10%
760
39%
760
20%
1664
December11th to 20thNight
32%
915
18%
3151
10%
914
39%
914
18%
2135
December21st to endNight
23%
1041
10%
4841
7%
1026
32%
1026
10%
3722

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%7%36%5%35%5%5%7%41%
74956
Night
14%7%36%5%3445%7%42%
75103
TransparencyDay
42%6%11%23%15%3
74662
Night
42%6%11%23%16%3
74918
SeeingDay
16%8%22%25%19%9%
14369
Night
17%7%25%32%17%2
24316

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%10%49%5%33445%35%
1517
11th to 20thDay
20%10%5%9%6%2435%6%30%
1520
21st to endDay
16%11%47%5%35%446%35%
1809
February1st to 10thDay
19%10%5%7%5%3435%5%34%
1800
11th to 20thDay
17%10%37%6%35%45%7%33%
1748
21st to endDay
16%11%48%6%35%36%7%31%
1480
March1st to 10thDay
17%8%36%5%35%435%42%
1800
11th to 20thDay
21%9%35%5%34446%34%
1859
21st to endDay
19%9%46%6%35%447%32%
2348
April1st to 10thDay
13%6%25%5%35%6%5%9%41%
2160
11th to 20thDay
16%8%36%5%25%46%6%39%
2134
21st to endDay
18%6%35%5%345%5%6%41%
2214
May1st to 10thDay
16%6%36%7%4446%7%36%
2340
11th to 20thDay
17%7%36%5%3445%7%37%
2301
21st to endDay
9%6%37%6%45%7%8%9%36%
2587
June1st to 10thDay
10%5%346%3445%9%46%
2520
11th to 20thDay
5%425%5%36%6%6%8%48%
2520
21st to endDay
8%4245%35%6%7%10%45%
2520
July1st to 10thDay
11%6%25%6%36%6%7%11%38%
2520
11th to 20thDay
6%425%5%36%6%7%11%45%
2520
21st to endDay
8%4346%46%6%7%10%42%
2681
August1st to 10thDay
7%5%245%46%6%7%9%44%
2259
11th to 20thDay
9%426%6%45%6%8%10%41%
2125
21st to endDay
7%5%245%35%5%6%9%48%
2376
September1st to 10thDay
9%5%36%6%345%5%7%47%
2160
11th to 20thDay
8%425%6%3346%8%49%
1994
21st to endDay
12%423434346%54%
1980
October1st to 10thDay
11%42343345%6%55%
1980
11th to 20thDay
14%5%25%5%2445%7%47%
1860
21st to endDay
19%7%35%424435%43%
1792
November1st to 10thDay
10%43343445%7%54%
1672
11th to 20thDay
16%7%36%424447%44%
1710
21st to endDay
19%8%35%324446%41%
1710
December1st to 10thDay
20%11%46%433335%37%
1710
11th to 20thDay
17%11%6%8%5%3445%6%32%
1947
21st to endDay
24%16%6%6%6%34445%23%
2783
January1st to 10thNight
17%9%47%5%34446%36%
2648
11th to 20thNight
20%10%5%8%6%34346%32%
2660
21st to endNight
17%10%48%5%345%5%6%33%
2686
February1st to 10thNight
22%11%47%5%3445%5%30%
2160
11th to 20thNight
17%8%37%6%35%445%38%
2098
21st to endNight
20%10%48%42346%6%34%
1776
March1st to 10thNight
17%8%35%5%245%45%42%
2160
11th to 20thNight
17%9%47%5%3445%5%37%
2099
21st to endNight
21%7%36%6%245%5%7%35%
2021
April1st to 10thNight
12%7%25%5%245%5%7%47%
1800
11th to 20thNight
17%6%25%5%33446%44%
1775
21st to endNight
18%6%36%6%345%48%37%
1746
May1st to 10thNight
16%7%35%5%345%6%7%40%
1620
11th to 20thNight
12%6%36%6%45%5%5%8%41%
1592
21st to endNight
6%5%36%5%46%6%8%10%40%
1684
June1st to 10thNight
10%5%244345%6%7%49%
1440
11th to 20thNight
6%4145%35%5%7%9%50%
1440
21st to endNight
5%3134346%6%11%54%
1440
July1st to 10thNight
8%435%5%446%6%9%48%
1440
11th to 20thNight
5%33443445%9%56%
1440
21st to endNight
7%425%435%5%6%10%49%
1634
August1st to 10thNight
6%4245%3446%9%53%
1675
11th to 20thNight
5%5%35%5%36%6%7%9%47%
1776
21st to endNight
6%42442447%9%55%
1980
September1st to 10thNight
11%425%43445%7%53%
1800
11th to 20thNight
7%415%4345%6%7%54%
1948
21st to endNight
11%42433445%7%53%
1980
October1st to 10thNight
9%424423346%58%
1980
11th to 20thNight
15%5%24423346%51%
2096
21st to endNight
18%7%25%424345%45%
2564
November1st to 10thNight
12%5%24423346%53%
2406
11th to 20thNight
14%5%35%434446%48%
2470
21st to endNight
19%7%35%434336%43%
2470
December1st to 10thNight
20%9%36%5%335%47%36%
2470
11th to 20thNight
18%10%46%4345%5%5%36%
3245
21st to endNight
22%16%47%7%35%445%24%
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
52%49%21%12%1
1518
11th to 20thDay
56%312%20%8%
1520
21st to endDay
49%5%11%26%7%2
1809
February1st to 10thDay
53%310%21%11%1
1800
11th to 20thDay
51%5%9%21%11%2
1758
21st to endDay
53%410%19%11%3
1480
March1st to 10thDay
46%48%24%17%1
1800
11th to 20thDay
52%412%21%9%2
1859
21st to endDay
53%411%22%8%2
2348
April1st to 10thDay
39%8%13%24%16%
2160
11th to 20thDay
45%5%10%22%16%3
2134
21st to endDay
43%6%12%24%12%2
2214
May1st to 10thDay
47%7%13%23%10%1
2340
11th to 20thDay
46%7%13%19%14%1
2305
21st to endDay
41%9%16%19%12%2
2587
June1st to 10thDay
35%7%11%25%19%3
2520
11th to 20thDay
31%9%12%26%18%3
2520
21st to endDay
32%9%13%23%17%5%
2520
July1st to 10thDay
38%9%14%21%14%4
2451
11th to 20thDay
31%8%17%25%16%4
2445
21st to endDay
34%10%15%24%15%2
2532
August1st to 10thDay
33%10%15%27%15%1
2246
11th to 20thDay
36%9%13%25%15%2
2125
21st to endDay
31%7%14%23%18%6%
2376
September1st to 10thDay
36%5%10%25%19%4
2160
11th to 20thDay
32%6%10%27%22%3
1994
21st to endDay
31%5%7%25%27%4
1980
October1st to 10thDay
30%5%9%26%26%4
1980
11th to 20thDay
37%5%8%24%22%5%
1860
21st to endDay
44%49%23%17%3
1792
November1st to 10thDay
31%6%10%31%17%6%
1672
11th to 20thDay
41%5%8%24%19%5%
1710
21st to endDay
46%5%8%23%17%2
1710
December1st to 10thDay
51%410%22%12%1
1710
11th to 20thDay
54%39%22%11%1
1944
21st to endDay
63%5%10%14%8%
2783
January1st to 10thNight
49%410%22%13%2
2648
11th to 20thNight
54%412%20%9%1
2660
21st to endNight
51%5%11%21%10%2
2686
February1st to 10thNight
56%5%11%20%8%1
2160
11th to 20thNight
49%49%23%14%2
2099
21st to endNight
51%5%11%19%12%3
1776
March1st to 10thNight
45%5%8%21%17%4
2160
11th to 20thNight
49%6%12%19%13%2
2099
21st to endNight
49%6%12%21%9%2
2021
April1st to 10thNight
37%5%11%27%17%3
1800
11th to 20thNight
41%49%21%19%5%
1775
21st to endNight
46%6%9%21%16%2
1746
May1st to 10thNight
44%6%10%26%12%2
1620
11th to 20thNight
42%9%11%19%18%1
1593
21st to endNight
36%9%14%21%15%4
1685
June1st to 10thNight
32%6%11%25%22%3
1440
11th to 20thNight
27%8%14%22%23%6%
1440
21st to endNight
24%8%16%25%19%8%
1440
July1st to 10thNight
31%9%15%24%17%4
1400
11th to 20thNight
26%8%13%29%18%6%
1392
21st to endNight
28%8%13%30%18%3
1543
August1st to 10thNight
27%8%18%25%20%3
1664
11th to 20thNight
30%9%13%27%19%3
1776
21st to endNight
25%8%13%27%22%6%
1980
September1st to 10thNight
31%6%9%27%21%7%
1800
11th to 20thNight
28%6%10%26%25%5%
1948
21st to endNight
31%6%8%24%25%7%
1980
October1st to 10thNight
28%6%9%22%29%6%
1980
11th to 20thNight
35%47%25%23%6%
2096
21st to endNight
43%38%24%17%5%
2564
November1st to 10thNight
33%310%25%23%6%
2406
11th to 20thNight
37%48%23%22%6%
2470
21st to endNight
44%49%24%17%2
2470
December1st to 10thNight
48%5%12%22%13%1
2470
11th to 20thNight
49%410%21%15%1
3247
21st to endNight
63%5%9%14%8%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
25%17%29%21%6%1
270
11th to 20thDay
28%17%33%19%3
270
21st to endDay
25%19%35%15%5%
282
February1st to 10thDay
26%15%41%14%31
240
11th to 20thDay
28%19%36%15%3
240
21st to endDay
28%15%34%19%5%
198
March1st to 10thDay
22%14%42%17%5%
240
11th to 20thDay
27%14%34%18%7%1
299
21st to endDay
27%13%34%16%8%1
462
April1st to 10thDay
15%14%32%28%10%2
420
11th to 20thDay
21%15%25%21%16%2
412
21st to endDay
22%11%31%24%8%4
420
May1st to 10thDay
18%13%28%28%9%4
423
11th to 20thDay
20%7%21%30%14%8%
447
21st to endDay
13%321%29%22%13%
541
June1st to 10thDay
13%415%26%30%12%
630
11th to 20thDay
7%318%32%27%13%
630
21st to endDay
11%320%33%21%12%
630
July1st to 10thDay
12%212%22%28%24%
621
11th to 20thDay
6%412%30%30%17%
618
21st to endDay
8%211%30%34%15%
622
August1st to 10thDay
12%210%27%30%19%
446
11th to 20thDay
14%211%27%33%13%
439
21st to endDay
8%210%23%36%21%
495
September1st to 10thDay
10%313%23%36%15%
450
11th to 20thDay
8%38%30%33%18%
450
21st to endDay
13%6%19%23%25%15%
450
October1st to 10thDay
12%420%34%23%8%
450
11th to 20thDay
13%10%34%25%12%5%
330
21st to endDay
27%11%28%24%10%
297
November1st to 10thDay
16%5%32%27%14%7%
270
11th to 20thDay
17%20%27%25%10%2
270
21st to endDay
25%9%31%26%9%1
270
December1st to 10thDay
20%21%30%18%7%4
270
11th to 20thDay
27%12%31%22%7%1
270
21st to endDay
28%20%29%19%5%
297
January1st to 10thNight
23%12%32%29%4
950
11th to 20thNight
27%12%35%22%4
950
21st to endNight
22%11%38%27%3
974
February1st to 10thNight
27%10%33%27%2
720
11th to 20thNight
23%12%37%26%2
703
21st to endNight
27%13%36%22%2
592
March1st to 10thNight
22%11%34%29%5%
720
11th to 20thNight
22%9%34%26%8%1
720
21st to endNight
24%8%27%33%8%
635
April1st to 10thNight
14%11%31%37%8%
540
11th to 20thNight
20%8%28%29%14%2
533
21st to endNight
21%5%30%32%10%2
540
May1st to 10thNight
17%6%27%36%13%1
540
11th to 20thNight
15%419%37%22%2
531
21st to endNight
8%118%39%29%4
584
June1st to 10thNight
12%116%39%29%3
540
11th to 20thNight
6%215%42%32%2
540
21st to endNight
5%116%41%34%3
540
July1st to 10thNight
10%8%33%38%10%
525
11th to 20thNight
6%29%32%45%6%
522
21st to endNight
7%29%37%37%7%
591
August1st to 10thNight
7%26%37%42%7%
537
11th to 20thNight
6%18%37%41%6%
534
21st to endNight
7%17%35%43%8%
594
September1st to 10thNight
12%19%33%39%6%
540
11th to 20thNight
8%213%35%38%6%
688
21st to endNight
13%419%30%29%6%
720
October1st to 10thNight
10%5%17%37%27%5%
720
11th to 20thNight
18%6%26%34%16%2
720
21st to endNight
21%8%30%29%11%
792
November1st to 10thNight
15%6%26%38%13%1
740
11th to 20thNight
16%9%33%30%11%
760
21st to endNight
22%9%27%32%10%
760
December1st to 10thNight
23%8%32%30%6%
760
11th to 20thNight
26%6%30%30%7%1
916
21st to endNight
28%11%32%24%4
1045
Page generated at 2024-01-24 09:37:32. Version ac07

Copyright 2024 Attilla Danko


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