Black Forest
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Black Forest clear sky chart from 2005-11-06 to 2024-01-31.

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
24%
22853
12%
74992
7%
22812
30%
22812
13%
56188

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
8%
760
8%
2649
4%
757
13%
757
5%
2236
January11th to 20thNight
10%
760
7%
2660
2%
760
16%
760
5%
2242
January21st to endNight
11%
835
8%
2820
4%
835
17%
835
7%
2267
February1st to 10thNight
6%
720
6%
2340
1%
720
12%
720
5%
2016
February11th to 20thNight
9%
703
9%
2199
2%
700
18%
700
6%
1812
February21st to endNight
11%
592
11%
1776
4%
592
20%
592
8%
1435
March1st to 10thNight
13%
720
12%
2160
4%
720
23%
720
11%
1682
March11th to 20thNight
15%
720
13%
2014
5%
720
23%
720
13%
1566
March21st to endNight
17%
792
18%
2034
5%
792
26%
792
16%
1514
April1st to 10thNight
17%
720
13%
1800
2%
720
23%
720
15%
1405
April11th to 20thNight
21%
711
12%
1775
3%
711
26%
711
18%
1354
April21st to endNight
25%
680
15%
1760
6%
680
31%
680
19%
1292
May1st to 10thNight
27%
407
14%
1487
9%
407
34%
407
14%
1064
May11th to 20thNight
29%
354
18%
1416
14%
354
41%
354
17%
910
May21st to endNight
41%
388
13%
1551
12%
388
49%
388
19%
980
June1st to 10thNight
40%
360
13%
1440
13%
360
50%
360
18%
924
June11th to 20thNight
39%
360
13%
1440
15%
360
46%
360
18%
905
June21st to endNight
38%
360
12%
1440
12%
360
46%
360
17%
923
July1st to 10thNight
52%
350
13%
1400
16%
350
58%
350
23%
837
July11th to 20thNight
54%
348
16%
1392
22%
348
59%
348
25%
818
July21st to endNight
53%
394
16%
1486
19%
372
56%
372
22%
904
August1st to 10thNight
51%
411
15%
1475
15%
409
53%
409
23%
925
August11th to 20thNight
46%
617
14%
1681
9%
617
48%
617
25%
1165
August21st to endNight
48%
792
18%
1980
9%
792
51%
792
31%
1335
September1st to 10thNight
45%
720
15%
1800
7%
720
47%
720
28%
1244
September11th to 20thNight
44%
720
23%
1831
13%
720
49%
720
32%
1209
September21st to endNight
40%
720
21%
1980
15%
720
45%
720
26%
1342
October1st to 10thNight
30%
720
14%
2160
10%
720
35%
720
16%
1585
October11th to 20thNight
24%
720
12%
2160
7%
720
31%
720
16%
1583
October21st to endNight
16%
792
10%
2520
5%
792
24%
792
10%
1999
November1st to 10thNight
22%
740
14%
2407
9%
740
29%
740
14%
1757
November11th to 20thNight
16%
760
15%
2531
8%
760
26%
760
12%
1903
November21st to endNight
15%
760
10%
2660
5%
760
22%
760
8%
2104
December1st to 10thNight
9%
760
5%
2660
1%
760
14%
760
5%
2257
December11th to 20thNight
11%
760
6%
3267
2%
759
16%
759
4%
2725
December21st to endNight
7%
827
4%
4841
1%
817
12%
817
3%
3969

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
20%12%5%7%6%3445%6%28%
74899
Night
20%13%5%8%6%34446%27%
75227
TransparencyDay
58%410%18%9%1
74604
Night
59%410%17%9%1
75056
SeeingDay
29%16%28%17%8%2
13598
Night
27%16%27%21%7%1
22863

By Month

Percentage Cloud Cover NE (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%22%9%13%7%4433415%
1517
11th to 20thDay
18%22%7%10%9%3334318%
1520
21st to endDay
14%18%8%14%10%45%44416%
1762
February1st to 10thDay
16%20%8%13%10%46%43313%
1620
11th to 20thDay
15%18%8%15%8%3343419%
1649
21st to endDay
19%17%7%12%8%4443417%
1480
March1st to 10thDay
15%15%8%13%6%34445%24%
1797
11th to 20thDay
17%17%7%8%5%3444427%
1944
21st to endDay
22%13%46%6%24335%31%
2322
April1st to 10thDay
21%15%6%6%423336%30%
2160
11th to 20thDay
20%13%37%5%2345%5%33%
2134
21st to endDay
23%16%36%434436%28%
2200
May1st to 10thDay
23%12%46%5%4444431%
2488
11th to 20thDay
20%9%35%5%35%447%35%
2478
21st to endDay
20%7%35%5%3446%8%34%
2725
June1st to 10thDay
24%7%35%5%35%5%6%8%28%
2520
11th to 20thDay
23%7%25%435%5%6%8%31%
2520
21st to endDay
21%8%37%5%35%45%8%30%
2520
July1st to 10thDay
18%7%35%5%35%5%6%8%36%
2520
11th to 20thDay
16%7%35%6%35%6%5%10%33%
2520
21st to endDay
18%6%26%6%46%6%6%8%32%
2744
August1st to 10thDay
18%6%35%5%46%5%6%8%35%
2449
11th to 20thDay
18%7%36%6%35%5%7%8%31%
2201
21st to endDay
19%6%26%5%35%5%5%9%35%
2376
September1st to 10thDay
19%5%25%5%35%6%6%8%36%
2160
11th to 20thDay
19%6%25%43445%7%41%
2129
21st to endDay
21%7%25%6%3445%7%35%
1977
October1st to 10thDay
26%10%37%6%44345%29%
1800
11th to 20thDay
24%12%36%5%445%5%6%28%
1800
21st to endDay
30%12%46%5%335%45%21%
1834
November1st to 10thDay
19%13%5%6%6%445%5%5%28%
1671
11th to 20thDay
20%18%5%7%5%2345%5%26%
1644
21st to endDay
20%20%8%9%5%33445%19%
1520
December1st to 10thDay
22%25%9%10%5%2343313%
1520
11th to 20thDay
22%17%11%14%7%3323415%
1906
21st to endDay
24%20%9%12%6%3333315%
2772
January1st to 10thNight
17%21%8%13%8%3433415%
2649
11th to 20thNight
18%19%8%13%9%4433416%
2660
21st to endNight
14%16%8%12%8%46%445%19%
2820
February1st to 10thNight
18%16%8%15%10%45%34413%
2340
11th to 20thNight
15%13%9%14%9%45%44418%
2197
21st to endNight
17%15%7%11%7%5%4446%19%
1776
March1st to 10thNight
16%12%7%12%8%34445%24%
2150
11th to 20thNight
16%17%7%7%6%3443428%
2013
21st to endNight
19%14%47%5%2335%6%31%
2034
April1st to 10thNight
23%14%5%7%434346%28%
1800
11th to 20thNight
21%12%35%5%35%446%31%
1775
21st to endNight
22%11%45%43445%6%33%
1760
May1st to 10thNight
24%11%35%5%44345%32%
1487
11th to 20thNight
17%9%24435%46%7%37%
1415
21st to endNight
17%6%25%5%35%5%5%8%39%
1550
June1st to 10thNight
22%5%34435%5%7%6%36%
1440
11th to 20thNight
23%6%2433345%9%38%
1440
21st to endNight
19%6%35%5%35%5%5%8%37%
1440
July1st to 10thNight
15%6%34435%6%5%8%42%
1440
11th to 20thNight
14%6%25%435%5%6%9%42%
1440
21st to endNight
14%7%36%6%3346%7%42%
1574
August1st to 10thNight
18%5%245%3446%8%41%
1485
11th to 20thNight
18%6%26%6%345%5%7%38%
1681
21st to endNight
16%6%3443445%7%43%
1980
September1st to 10thNight
18%6%244345%6%6%42%
1800
11th to 20thNight
18%5%35%423346%47%
1831
21st to endNight
21%6%2443445%7%39%
1980
October1st to 10thNight
26%8%36%5%3444432%
2160
11th to 20thNight
24%10%36%5%35%45%6%30%
2160
21st to endNight
29%12%47%6%34446%21%
2520
November1st to 10thNight
19%14%47%6%24436%30%
2407
11th to 20thNight
22%16%5%6%5%34445%27%
2531
21st to endNight
20%19%6%9%5%34445%20%
2660
December1st to 10thNight
21%24%9%10%5%2444414%
2660
11th to 20thNight
22%18%8%13%7%2433416%
3288
21st to endNight
27%19%7%12%5%23335%14%
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
74%35%12%5%
1518
11th to 20thDay
71%46%10%7%3
1520
21st to endDay
73%36%10%5%2
1762
February1st to 10thDay
77%35%11%41
1620
11th to 20thDay
70%46%12%8%1
1658
21st to endDay
71%47%10%7%
1480
March1st to 10thDay
64%39%14%8%2
1800
11th to 20thDay
61%49%13%11%2
1944
21st to endDay
58%36%16%14%3
2322
April1st to 10thDay
58%37%20%10%2
2160
11th to 20thDay
53%49%21%12%1
2134
21st to endDay
59%48%16%10%3
2200
May1st to 10thDay
57%47%18%11%2
2488
11th to 20thDay
50%5%9%23%11%2
2482
21st to endDay
48%6%16%20%10%1
2725
June1st to 10thDay
54%5%13%18%10%
2520
11th to 20thDay
51%413%23%8%1
2520
21st to endDay
53%5%14%19%8%1
2520
July1st to 10thDay
46%5%13%24%11%1
2450
11th to 20thDay
46%6%15%26%6%
2445
21st to endDay
49%7%13%22%9%
2591
August1st to 10thDay
47%6%15%23%9%
2435
11th to 20thDay
50%6%15%22%7%
2201
21st to endDay
47%6%13%25%9%1
2376
September1st to 10thDay
44%7%11%26%11%
2160
11th to 20thDay
44%410%26%15%1
2129
21st to endDay
49%5%10%24%12%1
1977
October1st to 10thDay
60%38%18%10%1
1800
11th to 20thDay
57%5%13%18%6%1
1800
21st to endDay
67%410%11%7%1
1834
November1st to 10thDay
58%5%12%17%9%
1671
11th to 20thDay
61%5%9%14%9%2
1644
21st to endDay
67%5%12%10%5%1
1520
December1st to 10thDay
77%38%9%21
1520
11th to 20thDay
76%47%9%4
1906
21st to endDay
78%347%9%
2772
January1st to 10thNight
74%45%10%6%
2649
11th to 20thNight
74%46%8%5%2
2660
21st to endNight
68%46%13%7%2
2820
February1st to 10thNight
77%27%9%5%1
2340
11th to 20thNight
69%5%6%13%6%
2199
21st to endNight
68%48%12%7%1
1776
March1st to 10thNight
64%39%16%7%1
2160
11th to 20thNight
62%48%16%9%1
2014
21st to endNight
55%39%18%12%3
2034
April1st to 10thNight
59%49%19%7%2
1800
11th to 20thNight
55%5%9%19%12%
1775
21st to endNight
54%310%18%12%3
1760
May1st to 10thNight
57%49%15%14%2
1487
11th to 20thNight
46%6%10%23%13%2
1416
21st to endNight
45%5%15%22%11%2
1551
June1st to 10thNight
47%5%14%22%11%1
1440
11th to 20thNight
45%5%14%23%11%1
1440
21st to endNight
46%6%13%24%10%1
1440
July1st to 10thNight
41%5%15%24%13%1
1400
11th to 20thNight
40%417%29%10%
1392
21st to endNight
42%5%14%27%10%1
1486
August1st to 10thNight
42%6%17%26%9%
1475
11th to 20thNight
47%5%14%25%10%
1681
21st to endNight
41%5%13%29%11%
1980
September1st to 10thNight
43%5%14%26%11%1
1800
11th to 20thNight
40%410%29%16%1
1831
21st to endNight
45%411%26%12%2
1980
October1st to 10thNight
57%410%17%12%1
2160
11th to 20thNight
55%5%13%19%6%1
2160
21st to endNight
65%5%10%12%8%1
2520
November1st to 10thNight
56%5%11%15%11%2
2407
11th to 20thNight
60%49%16%8%3
2531
21st to endNight
66%410%15%41
2660
December1st to 10thNight
75%48%9%3
2660
11th to 20thNight
74%48%9%5%
3288
21st to endNight
75%28%8%6%
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
33%17%33%13%3
180
11th to 20thDay
36%27%29%6%21
180
21st to endDay
27%23%36%11%3
242
February1st to 10thDay
44%30%25%1
240
11th to 20thDay
35%29%30%5%1
316
21st to endDay
36%24%32%7%1
346
March1st to 10thDay
30%27%28%13%2
420
11th to 20thDay
29%27%30%11%3
420
21st to endDay
36%21%24%14%32
462
April1st to 10thDay
35%25%23%11%5%
420
11th to 20thDay
34%21%21%14%8%1
412
21st to endDay
36%16%28%13%42
420
May1st to 10thDay
35%17%27%12%6%4
423
11th to 20thDay
27%13%33%20%6%2
447
21st to endDay
25%13%31%18%12%2
485
June1st to 10thDay
27%16%30%18%7%2
450
11th to 20thDay
24%13%27%26%8%2
450
21st to endDay
26%13%31%19%7%2
450
July1st to 10thDay
21%7%27%29%14%3
445
11th to 20thDay
19%6%31%30%11%3
444
21st to endDay
20%7%36%26%8%2
488
August1st to 10thDay
19%9%25%28%15%5%
446
11th to 20thDay
23%8%25%23%14%7%
439
21st to endDay
20%14%27%20%13%6%
495
September1st to 10thDay
22%10%25%23%15%6%
450
11th to 20thDay
20%10%27%19%14%9%
450
21st to endDay
22%10%31%20%12%4
450
October1st to 10thDay
33%12%24%15%13%3
450
11th to 20thDay
30%17%31%16%6%1
450
21st to endDay
37%17%23%19%4
421
November1st to 10thDay
34%16%24%17%9%
365
11th to 20thDay
34%25%25%12%41
304
21st to endDay
37%25%28%8%1
180
December1st to 10thDay
37%22%29%8%4
180
11th to 20thDay
37%26%28%7%3
180
21st to endDay
38%24%29%8%2
198
January1st to 10thNight
31%26%30%12%1
760
11th to 20thNight
33%22%28%13%2
760
21st to endNight
21%25%34%17%3
835
February1st to 10thNight
29%26%33%11%1
720
11th to 20thNight
25%28%32%12%2
703
21st to endNight
29%23%32%14%2
592
March1st to 10thNight
24%24%33%16%2
720
11th to 20thNight
30%21%32%15%3
720
21st to endNight
27%23%29%15%6%1
792
April1st to 10thNight
29%19%31%19%2
720
11th to 20thNight
29%17%30%16%8%
711
21st to endNight
32%15%26%21%6%
680
May1st to 10thNight
31%10%28%23%8%1
407
11th to 20thNight
22%14%31%26%6%1
354
21st to endNight
19%5%29%35%12%1
389
June1st to 10thNight
25%6%23%35%10%1
360
11th to 20thNight
24%8%24%30%14%
360
21st to endNight
23%5%28%34%11%
360
July1st to 10thNight
17%421%39%18%1
350
11th to 20thNight
14%422%39%18%2
348
21st to endNight
16%6%21%43%13%1
394
August1st to 10thNight
20%318%39%19%1
411
11th to 20thNight
22%420%31%21%3
617
21st to endNight
19%6%21%36%17%2
792
September1st to 10thNight
20%8%23%31%16%2
720
11th to 20thNight
23%6%23%28%17%4
720
21st to endNight
24%8%26%26%14%2
720
October1st to 10thNight
30%10%24%21%12%2
720
11th to 20thNight
30%12%29%23%6%1
720
21st to endNight
36%16%27%19%2
792
November1st to 10thNight
26%18%29%20%7%
740
11th to 20thNight
32%18%30%13%6%1
760
21st to endNight
30%22%29%16%31
760
December1st to 10thNight
36%22%26%13%2
760
11th to 20thNight
33%25%25%13%41
760
21st to endNight
36%26%25%12%1
836
Page generated at 2024-01-28 05:26:35. Version ac07

Copyright 2024 Attilla Danko


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