Gothenburg
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Gothenburg clear sky chart from 2005-11-06 to 2024-03-01.

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
42%
24828
23%
79985
13%
24732
51%
24732
32%
45842

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
37%
940
21%
4372
12%
926
48%
926
19%
2652
January11th to 20thNight
36%
946
24%
4305
12%
930
46%
930
24%
2201
January21st to endNight
31%
1035
18%
4478
8%
1023
44%
1023
21%
2649
February1st to 10thNight
31%
873
20%
2393
8%
873
40%
873
28%
1565
February11th to 20thNight
34%
744
22%
2218
11%
740
43%
740
30%
1343
February21st to endNight
33%
628
25%
1884
8%
628
47%
628
34%
1068
March1st to 10thNight
33%
722
24%
2166
9%
722
46%
722
34%
1231
March11th to 20thNight
34%
568
24%
2008
16%
568
47%
568
29%
1108
March21st to endNight
31%
594
16%
2160
9%
594
41%
594
22%
1304
April1st to 10thNight
27%
540
20%
1800
11%
540
40%
540
27%
1037
April11th to 20thNight
25%
533
20%
1734
10%
533
41%
533
26%
1032
April21st to endNight
36%
540
21%
1620
15%
540
47%
540
29%
980
May1st to 10thNight
34%
540
16%
1620
10%
540
44%
540
27%
1047
May11th to 20thNight
34%
531
16%
1593
11%
531
40%
531
26%
1019
May21st to endNight
37%
582
14%
1705
6%
582
44%
582
25%
1126
June1st to 10thNight
52%
540
18%
1440
9%
540
56%
540
39%
854
June11th to 20thNight
43%
540
21%
1440
7%
540
49%
540
39%
860
June21st to endNight
55%
540
20%
1440
9%
540
59%
540
42%
860
July1st to 10thNight
57%
525
15%
1400
7%
525
60%
525
37%
876
July11th to 20thNight
63%
522
23%
1392
14%
522
68%
522
47%
789
July21st to endNight
65%
591
23%
1581
19%
558
69%
558
44%
893
August1st to 10thNight
66%
537
19%
1601
18%
534
70%
534
35%
947
August11th to 20thNight
63%
534
25%
1600
24%
534
69%
534
41%
878
August21st to endNight
65%
594
27%
1965
28%
594
72%
594
43%
984
September1st to 10thNight
56%
540
28%
1845
26%
540
67%
540
40%
937
September11th to 20thNight
55%
540
29%
1980
25%
540
67%
540
39%
953
September21st to endNight
49%
540
31%
1980
25%
540
60%
540
39%
950
October1st to 10thNight
43%
540
31%
1980
22%
540
56%
540
30%
1064
October11th to 20thNight
43%
676
31%
2116
16%
676
55%
676
40%
1092
October21st to endNight
40%
990
29%
2574
13%
990
48%
990
41%
1484
November1st to 10thNight
46%
925
31%
2405
12%
925
55%
925
49%
1293
November11th to 20thNight
40%
950
33%
2470
13%
950
52%
950
42%
1432
November21st to endNight
46%
950
29%
2470
15%
950
54%
950
43%
1421
December1st to 10thNight
37%
950
26%
2470
10%
950
49%
950
39%
1468
December11th to 20thNight
35%
948
29%
3020
12%
948
47%
948
34%
1583
December21st to endNight
35%
1040
17%
4760
10%
1026
47%
1026
19%
2862

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
8%6%25%42445%7%52%
78564
Night
8%6%25%43445%7%52%
80882
TransparencyDay
31%6%14%28%18%4
78275
Night
31%6%14%27%19%4
80694
SeeingDay
11%8%30%33%15%2
14729
Night
10%8%35%37%9%
24861

By Month

Percentage Cloud Cover SW (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
7%11%35%5%2435%6%50%
2538
11th to 20thDay
6%9%37%435%6%6%7%43%
2540
21st to endDay
47%46%5%3445%7%51%
2962
February1st to 10thDay
7%8%48%7%45%46%6%41%
1805
11th to 20thDay
5%5%47%5%3446%8%49%
1849
21st to endDay
7%7%35%32335%6%55%
1570
March1st to 10thDay
7%6%2432345%7%58%
1800
11th to 20thDay
11%7%2442346%6%50%
1952
21st to endDay
11%9%37%6%345%5%7%40%
2191
April1st to 10thDay
10%5%24424448%52%
2160
11th to 20thDay
14%7%245%3445%7%45%
2174
21st to endDay
15%5%2442345%7%48%
2340
May1st to 10thDay
12%6%246%3446%8%45%
2340
11th to 20thDay
16%5%3443345%8%45%
2302
21st to endDay
13%5%25%5%345%5%8%45%
2567
June1st to 10thDay
6%3133235%6%10%58%
2520
11th to 20thDay
7%3244345%5%8%54%
2520
21st to endDay
43233345%6%10%58%
2520
July1st to 10thDay
6%32433447%9%55%
2520
11th to 20thDay
5%3133245%5%8%60%
2520
21st to endDay
5%3244345%7%10%53%
2642
August1st to 10thDay
8%425%5%35%6%7%10%46%
2328
11th to 20thDay
6%3244245%5%8%57%
2301
21st to endDay
7%42342445%6%59%
2388
September1st to 10thDay
10%424423447%57%
2113
11th to 20thDay
7%41442445%7%58%
1980
21st to endDay
10%423223345%63%
1980
October1st to 10thDay
13%6%23313346%58%
1980
11th to 20thDay
8%5%24413445%60%
1821
21st to endDay
12%6%23424345%56%
1782
November1st to 10thDay
6%5%2343445%7%57%
1673
11th to 20thDay
5%6%24324346%62%
1710
21st to endDay
8%7%3332335%6%57%
1710
December1st to 10thDay
6%5%46%5%23446%54%
1710
11th to 20thDay
6%7%26%5%34336%54%
1962
21st to endDay
11%13%38%6%34335%40%
2794
January1st to 10thNight
7%9%49%7%3445%7%42%
4417
11th to 20thNight
48%36%42345%7%52%
4430
21st to endNight
48%47%5%45%5%5%7%47%
4690
February1st to 10thNight
9%8%46%5%25%5%5%7%44%
2393
11th to 20thNight
47%36%6%45%5%5%8%47%
2218
21st to endNight
47%36%5%2445%6%55%
1884
March1st to 10thNight
7%7%25%433446%55%
2166
11th to 20thNight
9%7%24424447%52%
2008
21st to endNight
11%8%45%435%5%5%7%44%
2160
April1st to 10thNight
11%6%245%2446%8%47%
1800
11th to 20thNight
13%5%24425%6%6%6%48%
1734
21st to endNight
11%6%244345%6%8%47%
1620
May1st to 10thNight
11%5%25%5%45%6%7%8%42%
1620
11th to 20thNight
14%5%25%5%3335%7%46%
1593
21st to endNight
16%5%24435%5%6%9%42%
1705
June1st to 10thNight
6%3245%35%5%6%8%54%
1440
11th to 20thNight
10%41442446%9%53%
1440
21st to endNight
5%3145%25%7%6%10%53%
1440
July1st to 10thNight
6%434445%6%6%11%48%
1440
11th to 20thNight
32244346%7%9%56%
1440
21st to endNight
5%3144336%8%10%52%
1674
August1st to 10thNight
5%4246%45%5%8%10%49%
1611
11th to 20thNight
6%325%4336%7%7%55%
1600
21st to endNight
5%31333445%8%62%
1965
September1st to 10thNight
8%41332336%6%60%
1845
11th to 20thNight
6%31332445%6%62%
1980
21st to endNight
8%313423346%64%
1980
October1st to 10thNight
14%32342435%6%54%
1980
11th to 20thNight
8%5%23323236%63%
2116
21st to endNight
10%5%13322336%59%
2574
November1st to 10thNight
432342345%7%63%
2405
11th to 20thNight
6%5%34423447%57%
2470
21st to endNight
6%6%3342345%7%57%
2470
December1st to 10thNight
5%6%345%2445%6%56%
2470
11th to 20thNight
6%5%2342345%7%57%
3231
21st to endNight
12%14%34424346%43%
4873

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
36%413%33%13%1
2539
11th to 20thDay
37%9%12%24%13%3
2540
21st to endDay
31%6%17%27%16%2
2962
February1st to 10thDay
42%7%15%21%12%3
1805
11th to 20thDay
34%5%15%26%16%4
1859
21st to endDay
31%414%26%19%6%
1570
March1st to 10thDay
27%414%29%22%4
1800
11th to 20thDay
34%6%13%26%18%3
1952
21st to endDay
41%9%15%24%10%2
2191
April1st to 10thDay
31%5%17%27%17%3
2160
11th to 20thDay
39%6%15%23%15%3
2177
21st to endDay
36%5%12%29%17%1
2340
May1st to 10thDay
36%7%17%24%14%2
2340
11th to 20thDay
38%9%15%27%11%1
2306
21st to endDay
36%8%18%24%11%3
2567
June1st to 10thDay
21%8%21%34%14%2
2520
11th to 20thDay
27%7%14%27%18%7%
2520
21st to endDay
20%8%14%31%22%5%
2520
July1st to 10thDay
25%8%15%28%21%2
2451
11th to 20thDay
20%8%13%30%24%5%
2445
21st to endDay
23%9%19%32%16%1
2495
August1st to 10thDay
31%11%18%25%13%2
2314
11th to 20thDay
24%8%15%34%18%2
2301
21st to endDay
25%6%12%27%23%7%
2388
September1st to 10thDay
27%5%11%24%24%10%
2113
11th to 20thDay
24%7%11%28%25%5%
1980
21st to endDay
25%410%31%26%4
1980
October1st to 10thDay
29%49%28%26%3
1980
11th to 20thDay
26%5%9%30%22%8%
1821
21st to endDay
31%5%9%26%23%6%
1782
November1st to 10thDay
26%5%13%29%23%4
1673
11th to 20thDay
25%411%30%25%5%
1710
21st to endDay
29%313%27%24%5%
1710
December1st to 10thDay
30%5%14%30%18%3
1710
11th to 20thDay
32%414%32%17%1
1960
21st to endDay
48%5%9%23%13%2
2794
January1st to 10thNight
41%7%13%24%15%1
4417
11th to 20thNight
30%6%18%26%19%1
4430
21st to endNight
35%8%13%26%16%1
4690
February1st to 10thNight
39%6%14%23%14%4
2393
11th to 20thNight
34%7%13%27%16%3
2218
21st to endNight
31%413%24%21%7%
1884
March1st to 10thNight
31%5%12%25%22%6%
2166
11th to 20thNight
32%5%11%25%21%5%
2008
21st to endNight
38%7%17%23%13%2
2160
April1st to 10thNight
34%6%16%23%18%4
1800
11th to 20thNight
34%7%15%26%15%3
1734
21st to endNight
33%8%15%27%16%2
1620
May1st to 10thNight
36%10%17%21%15%1
1620
11th to 20thNight
37%8%17%24%12%1
1594
21st to endNight
38%10%19%18%11%3
1706
June1st to 10thNight
26%9%22%28%13%2
1440
11th to 20thNight
29%6%16%27%16%6%
1440
21st to endNight
25%9%16%27%20%2
1440
July1st to 10thNight
29%10%15%28%15%3
1400
11th to 20thNight
21%8%17%27%21%5%
1392
21st to endNight
22%9%20%30%16%3
1581
August1st to 10thNight
28%10%20%27%12%3
1601
11th to 20thNight
24%8%16%31%18%3
1600
21st to endNight
21%7%14%25%25%8%
1965
September1st to 10thNight
24%6%10%24%26%11%
1845
11th to 20thNight
23%6%12%27%25%7%
1980
21st to endNight
23%5%9%27%29%6%
1980
October1st to 10thNight
31%6%9%26%25%4
1980
11th to 20thNight
24%49%28%25%9%
2116
21st to endNight
28%412%25%23%9%
2574
November1st to 10thNight
20%5%13%29%25%8%
2405
11th to 20thNight
26%5%11%27%25%6%
2470
21st to endNight
27%411%28%24%5%
2470
December1st to 10thNight
28%5%14%29%19%4
2470
11th to 20thNight
25%5%12%38%18%1
3232
21st to endNight
41%5%12%29%12%1
4873

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
11%7%35%34%10%2
270
11th to 20thDay
12%13%33%34%6%1
270
21st to endDay
11%6%47%21%12%3
297
February1st to 10thDay
10%15%43%27%6%
270
11th to 20thDay
9%9%44%27%9%2
270
21st to endDay
13%14%41%28%4
225
March1st to 10thDay
10%9%42%25%12%2
240
11th to 20thDay
17%6%35%32%8%1
240
21st to endDay
20%11%40%17%10%1
277
April1st to 10thDay
12%21%40%21%6%
420
11th to 20thDay
19%16%34%25%5%
455
21st to endDay
19%14%31%26%10%1
600
May1st to 10thDay
13%11%34%31%10%1
603
11th to 20thDay
21%8%27%27%15%2
625
21st to endDay
16%9%33%29%12%1
679
June1st to 10thDay
6%6%26%32%23%8%
630
11th to 20thDay
8%7%35%35%14%2
630
21st to endDay
6%5%27%42%18%2
630
July1st to 10thDay
7%323%38%26%4
621
11th to 20thDay
6%122%40%27%4
618
21st to endDay
6%118%44%26%5%
684
August1st to 10thDay
8%317%43%25%4
626
11th to 20thDay
7%221%44%24%2
615
21st to endDay
7%322%43%21%4
507
September1st to 10thDay
10%325%41%17%4
403
11th to 20thDay
45%22%40%24%6%
270
21st to endDay
13%9%26%32%18%2
270
October1st to 10thDay
20%5%23%30%17%4
270
11th to 20thDay
9%10%37%31%10%3
270
21st to endDay
21%11%26%29%12%1
297
November1st to 10thDay
11%9%40%24%14%1
270
11th to 20thDay
11%11%36%31%11%1
270
21st to endDay
16%8%39%24%11%2
270
December1st to 10thDay
8%10%41%31%9%1
270
11th to 20thDay
14%9%36%30%10%1
270
21st to endDay
16%12%37%28%7%1
297
January1st to 10thNight
10%10%36%35%9%1
950
11th to 20thNight
8%13%37%34%7%1
950
21st to endNight
8%8%44%32%7%
1045
February1st to 10thNight
12%8%42%31%6%
873
11th to 20thNight
8%10%42%35%5%
744
21st to endNight
8%12%41%33%5%
628
March1st to 10thNight
11%9%42%33%5%
722
11th to 20thNight
13%8%40%32%5%1
568
21st to endNight
16%11%39%28%5%
594
April1st to 10thNight
14%12%44%29%2
540
11th to 20thNight
15%15%41%27%2
533
21st to endNight
16%11%35%30%8%
540
May1st to 10thNight
15%7%39%32%7%
540
11th to 20thNight
17%9%36%31%8%
531
21st to endNight
17%7%36%30%10%1
584
June1st to 10thNight
7%8%29%42%13%1
540
11th to 20thNight
11%6%36%37%11%
540
21st to endNight
6%431%50%10%
540
July1st to 10thNight
7%326%45%20%
525
11th to 20thNight
3126%54%15%1
522
21st to endNight
6%220%52%19%1
591
August1st to 10thNight
5%218%54%20%
537
11th to 20thNight
7%322%51%16%
534
21st to endNight
6%223%50%18%1
594
September1st to 10thNight
8%327%48%12%1
540
11th to 20thNight
7%430%43%15%1
540
21st to endNight
9%7%33%36%14%1
540
October1st to 10thNight
17%6%32%33%12%1
540
11th to 20thNight
11%11%33%33%11%
676
21st to endNight
14%10%32%34%10%1
990
November1st to 10thNight
7%7%36%40%9%1
925
11th to 20thNight
9%9%38%36%8%
950
21st to endNight
9%8%33%38%12%1
950
December1st to 10thNight
9%10%39%37%5%
950
11th to 20thNight
11%9%40%33%8%1
950
21st to endNight
15%10%35%34%6%
1045
Page generated at 2024-02-27 05:30:14. Version ac07

Copyright © 2024 Attilla Danko.


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