Rosthern
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Rosthern clear sky chart from 2005-11-06 to 2024-02-05.

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
41%
24117
11%
80735
8%
24061
46%
24061
19%
54665

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
35%
935
7%
4821
4%
926
40%
926
9%
3643
January11th to 20thNight
33%
936
9%
4670
6%
930
37%
930
9%
3491
January21st to endNight
28%
1030
7%
5021
5%
1023
33%
1023
9%
3433
February1st to 10thNight
39%
894
13%
2554
8%
894
43%
894
18%
1902
February11th to 20thNight
39%
700
14%
2272
11%
700
45%
700
18%
1593
February21st to endNight
52%
592
17%
1896
13%
592
58%
592
25%
1238
March1st to 10thNight
42%
720
12%
2160
9%
720
44%
720
20%
1573
March11th to 20thNight
40%
720
16%
2016
9%
720
46%
720
22%
1437
March21st to endNight
45%
671
13%
2057
11%
671
48%
671
20%
1446
April1st to 10thNight
44%
540
15%
1800
11%
540
49%
540
25%
1129
April11th to 20thNight
39%
533
13%
1682
9%
533
43%
533
20%
1162
April21st to endNight
36%
540
12%
1440
7%
540
40%
540
24%
1019
May1st to 10thNight
47%
540
13%
1440
7%
540
49%
540
30%
944
May11th to 20thNight
48%
531
8%
1418
6%
531
49%
531
33%
900
May21st to endNight
48%
409
3%
1253
3%
408
50%
408
24%
821
June1st to 10thNight
46%
360
0%
1080
0%
360
46%
360
26%
686
June11th to 20thNight
41%
360
0%
1080
0%
360
41%
360
19%
776
June21st to endNight
57%
360
0%
1080
0%
360
57%
360
29%
679
July1st to 10thNight
60%
350
0%
1050
0%
350
60%
350
31%
647
July11th to 20thNight
57%
348
2%
1211
2%
348
58%
348
28%
706
July21st to endNight
63%
443
9%
1349
7%
419
67%
419
43%
688
August1st to 10thNight
65%
537
12%
1424
7%
534
68%
534
41%
837
August11th to 20thNight
66%
534
16%
1432
10%
534
69%
534
39%
844
August21st to endNight
54%
594
19%
1840
15%
594
58%
594
34%
1070
September1st to 10thNight
49%
540
16%
1800
14%
540
53%
540
30%
1052
September11th to 20thNight
52%
540
18%
1800
16%
540
58%
540
27%
1098
September21st to endNight
46%
641
22%
2040
16%
641
55%
641
33%
1160
October1st to 10thNight
43%
720
18%
2160
12%
720
49%
720
24%
1453
October11th to 20thNight
44%
753
19%
2193
10%
753
50%
753
28%
1398
October21st to endNight
32%
990
15%
2628
5%
990
39%
990
20%
1920
November1st to 10thNight
31%
925
12%
2590
7%
925
35%
925
15%
2010
November11th to 20thNight
33%
950
10%
2669
5%
950
37%
950
15%
2090
November21st to endNight
29%
950
9%
2850
3%
950
34%
950
15%
2146
December1st to 10thNight
37%
950
10%
3019
6%
950
42%
950
16%
2235
December11th to 20thNight
26%
950
8%
3711
3%
949
33%
949
10%
2851
December21st to endNight
39%
1031
8%
5229
7%
1026
43%
1026
14%
2588

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%8%48%7%45%5%6%8%35%
77437
Night
8%8%48%7%46%5%6%8%35%
81369
TransparencyDay
45%9%17%21%8%1
77135
Night
45%8%16%21%9%1
81251
SeeingDay
13%7%25%30%19%6%
14684
Night
12%5%28%36%16%2
24180

By Month

Percentage Cloud Cover NW (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
6%16%7%15%9%48%5%45%19%
2095
11th to 20thDay
5%7%412%13%9%9%7%7%6%21%
2199
21st to endDay
6%11%5%12%8%45%6%5%8%31%
2598
February1st to 10thDay
7%8%49%11%5%7%7%8%9%24%
1517
11th to 20thDay
7%11%6%10%8%5%6%5%6%9%27%
1575
21st to endDay
5%9%412%10%6%8%7%7%8%25%
1360
March1st to 10thDay
9%13%6%9%10%5%8%6%6%8%21%
1800
11th to 20thDay
8%13%5%9%7%45%6%6%8%29%
1940
21st to endDay
8%12%48%8%46%5%6%8%31%
2299
April1st to 10thDay
7%9%48%7%45%5%6%8%36%
2160
11th to 20thDay
12%11%37%7%45%5%6%9%31%
2226
21st to endDay
13%9%48%6%45%5%5%9%33%
2520
May1st to 10thDay
13%6%27%5%45%6%6%10%37%
2520
11th to 20thDay
9%6%36%6%45%5%6%9%42%
2478
21st to endDay
17%7%36%5%35%5%6%8%34%
3019
June1st to 10thDay
14%6%36%6%46%6%8%8%34%
2880
11th to 20thDay
22%8%38%6%45%5%6%7%26%
2880
21st to endDay
13%5%25%6%37%6%7%9%37%
2880
July1st to 10thDay
9%5%25%5%45%5%7%10%44%
2880
11th to 20thDay
10%425%5%35%6%7%11%42%
2704
21st to endDay
7%4245%35%6%6%10%48%
2888
August1st to 10thDay
10%425%6%45%5%7%9%43%
2507
11th to 20thDay
9%5%25%6%35%5%6%10%45%
2466
21st to endDay
12%6%25%5%2446%8%45%
2516
September1st to 10thDay
11%5%26%6%3445%7%46%
2160
11th to 20thDay
11%7%37%7%345%6%8%39%
2160
21st to endDay
10%6%244345%5%8%49%
1918
October1st to 10thDay
15%8%35%5%3345%8%41%
1800
11th to 20thDay
11%9%46%6%3445%7%42%
1748
21st to endDay
11%10%410%8%46%6%5%5%31%
1728
November1st to 10thDay
16%15%5%8%8%25%45%7%26%
1488
11th to 20thDay
10%13%6%11%9%46%6%5%6%25%
1510
21st to endDay
8%13%8%11%8%5%6%5%5%8%23%
1330
December1st to 10thDay
5%12%5%11%10%5%8%6%6%8%24%
1159
11th to 20thDay
6%13%7%12%10%5%5%5%5%7%26%
1439
21st to endDay
39%48%6%35%5%5%6%44%
2090
January1st to 10thNight
5%11%7%14%11%5%6%5%7%6%21%
4848
11th to 20thNight
38%414%14%9%8%5%6%7%21%
4699
21st to endNight
7%11%5%9%8%46%5%7%8%29%
5062
February1st to 10thNight
6%9%5%11%9%5%7%6%7%8%27%
2554
11th to 20thNight
411%6%10%8%47%6%6%6%31%
2272
21st to endNight
48%5%9%7%46%7%8%8%35%
1896
March1st to 10thNight
9%10%49%8%47%6%6%8%30%
2160
11th to 20thNight
8%11%5%7%7%45%6%6%7%34%
2016
21st to endNight
8%9%47%7%5%7%6%7%8%33%
2057
April1st to 10thNight
6%9%46%7%45%5%7%8%40%
1800
11th to 20thNight
10%11%47%7%46%5%7%7%32%
1682
21st to endNight
13%7%39%7%35%5%5%7%36%
1440
May1st to 10thNight
12%6%26%6%36%448%43%
1440
11th to 20thNight
10%6%345%35%46%9%46%
1418
21st to endNight
16%5%25%5%36%6%5%9%37%
1253
June1st to 10thNight
12%5%26%6%345%6%9%41%
1080
11th to 20thNight
19%7%36%6%36%47%7%33%
1080
21st to endNight
9%6%245%36%5%7%8%44%
1080
July1st to 10thNight
6%435%5%36%7%7%9%44%
1080
11th to 20thNight
10%4145%35%6%6%9%47%
1252
21st to endNight
44134245%6%8%60%
1428
August1st to 10thNight
5%225%4345%6%8%56%
1432
11th to 20thNight
7%3145%35%5%6%10%52%
1432
21st to endNight
9%425%5%3445%9%50%
1840
September1st to 10thNight
10%5%25%5%245%6%8%49%
1800
11th to 20thNight
13%5%3442445%9%46%
1800
21st to endNight
9%5%25%435%46%9%49%
2040
October1st to 10thNight
13%9%47%43446%7%39%
2160
11th to 20thNight
8%7%46%6%35%45%7%45%
2193
21st to endNight
10%11%5%8%7%45%5%46%34%
2628
November1st to 10thNight
15%14%5%8%6%45%5%5%7%26%
2590
11th to 20thNight
8%11%6%11%9%5%6%5%6%7%26%
2669
21st to endNight
6%12%7%10%9%45%5%5%8%28%
2850
December1st to 10thNight
6%10%6%10%10%46%7%5%8%27%
3019
11th to 20thNight
8%12%6%13%9%5%6%6%6%7%22%
3753
21st to endNight
36%37%6%345%6%7%48%
5566

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
62%11%10%11%6%
2095
11th to 20thDay
57%11%13%15%4
2220
21st to endDay
50%10%16%18%6%
2598
February1st to 10thDay
52%10%15%16%7%
1517
11th to 20thDay
52%6%16%16%9%1
1584
21st to endDay
53%11%12%17%8%
1360
March1st to 10thDay
60%8%13%15%5%
1800
11th to 20thDay
51%8%14%21%6%
1941
21st to endDay
50%10%15%18%7%
2299
April1st to 10thDay
43%9%15%22%11%
2160
11th to 20thDay
50%8%14%18%9%1
2226
21st to endDay
47%8%18%20%7%1
2520
May1st to 10thDay
41%8%15%25%11%1
2520
11th to 20thDay
37%9%14%27%11%1
2482
21st to endDay
47%8%14%19%12%
3019
June1st to 10thDay
43%9%18%20%8%1
2880
11th to 20thDay
54%9%14%16%7%1
2880
21st to endDay
40%10%20%22%7%
2880
July1st to 10thDay
32%11%24%26%7%
2801
11th to 20thDay
33%13%24%26%4
2622
21st to endDay
30%11%25%28%6%
2727
August1st to 10thDay
34%12%23%25%5%
2491
11th to 20thDay
34%10%25%26%5%
2466
21st to endDay
36%6%18%33%7%
2516
September1st to 10thDay
36%8%18%25%11%2
2160
11th to 20thDay
43%8%18%24%7%1
2160
21st to endDay
32%7%17%31%11%2
1918
October1st to 10thDay
42%7%20%24%7%
1800
11th to 20thDay
42%6%17%26%9%1
1748
21st to endDay
52%9%15%19%4
1728
November1st to 10thDay
59%7%13%15%6%
1488
11th to 20thDay
60%9%14%13%4
1510
21st to endDay
58%10%14%14%4
1330
December1st to 10thDay
56%7%15%14%7%1
1159
11th to 20thDay
57%8%18%10%6%
1440
21st to endDay
40%6%14%19%18%3
2090
January1st to 10thNight
58%10%14%15%3
4848
11th to 20thNight
60%7%15%14%5%
4740
21st to endNight
50%11%15%18%6%
5062
February1st to 10thNight
52%9%13%19%8%
2554
11th to 20thNight
49%8%15%20%8%
2273
21st to endNight
41%8%18%24%9%
1896
March1st to 10thNight
49%9%15%19%7%
2160
11th to 20thNight
47%7%15%19%10%
2016
21st to endNight
47%9%15%21%8%1
2057
April1st to 10thNight
39%8%16%23%14%2
1800
11th to 20thNight
48%7%14%17%12%2
1682
21st to endNight
46%7%14%21%11%1
1440
May1st to 10thNight
39%7%13%26%14%1
1440
11th to 20thNight
34%7%13%25%18%2
1418
21st to endNight
41%8%15%21%13%1
1253
June1st to 10thNight
38%9%16%26%10%2
1080
11th to 20thNight
48%9%15%17%10%1
1080
21st to endNight
33%11%21%24%10%
1080
July1st to 10thNight
29%12%21%29%8%
1050
11th to 20thNight
32%9%22%29%7%
1211
21st to endNight
20%8%26%37%7%1
1349
August1st to 10thNight
25%9%24%32%9%
1424
11th to 20thNight
26%9%24%30%9%1
1432
21st to endNight
31%7%18%33%11%
1840
September1st to 10thNight
31%9%18%27%11%4
1800
11th to 20thNight
36%8%15%30%10%1
1800
21st to endNight
31%7%16%30%14%2
2040
October1st to 10thNight
43%7%16%26%8%
2160
11th to 20thNight
38%7%17%25%12%1
2193
21st to endNight
50%7%14%20%8%1
2628
November1st to 10thNight
57%8%13%15%6%1
2590
11th to 20thNight
56%10%16%14%4
2669
21st to endNight
54%9%17%16%4
2850
December1st to 10thNight
53%9%14%18%5%1
3019
11th to 20thNight
58%9%14%13%5%
3751
21st to endNight
34%6%15%27%16%3
5566

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
15%7%21%33%18%6%
180
11th to 20thDay
11%6%27%34%19%2
180
21st to endDay
13%5%26%33%20%2
241
February1st to 10thDay
9%6%30%34%19%3
252
11th to 20thDay
13%327%34%19%5%
240
21st to endDay
7%5%26%37%20%6%
198
March1st to 10thDay
14%5%23%38%18%3
240
11th to 20thDay
14%7%26%33%18%2
381
21st to endDay
15%6%27%31%18%3
462
April1st to 10thDay
9%9%35%28%13%5%
420
11th to 20thDay
13%12%27%30%15%4
420
21st to endDay
13%11%28%31%15%3
600
May1st to 10thDay
12%7%23%34%18%6%
603
11th to 20thDay
12%9%20%32%19%7%
625
21st to endDay
18%9%22%25%18%8%
679
June1st to 10thDay
13%8%31%29%15%4
630
11th to 20thDay
23%10%23%24%15%6%
630
21st to endDay
12%7%23%25%23%10%
630
July1st to 10thDay
11%420%32%25%7%
621
11th to 20thDay
10%6%21%30%24%8%
618
21st to endDay
6%6%22%29%27%10%
684
August1st to 10thDay
10%5%19%32%24%10%
626
11th to 20thDay
9%5%20%34%25%7%
604
21st to endDay
15%6%22%30%20%6%
495
September1st to 10thDay
14%10%28%29%16%3
450
11th to 20thDay
14%6%28%32%17%3
450
21st to endDay
12%7%27%31%21%2
311
October1st to 10thDay
18%425%29%20%5%
270
11th to 20thDay
13%11%29%27%15%5%
270
21st to endDay
14%9%33%25%13%4
297
November1st to 10thDay
21%5%30%29%13%2
270
11th to 20thDay
12%8%38%31%10%1
270
21st to endDay
14%436%33%11%2
270
December1st to 10thDay
8%6%24%34%20%7%
189
11th to 20thDay
11%7%32%33%17%
180
21st to endDay
11%426%32%17%10%
198
January1st to 10thNight
12%5%31%35%15%2
950
11th to 20thNight
11%6%32%37%12%1
950
21st to endNight
13%7%34%36%9%1
1045
February1st to 10thNight
10%428%37%19%2
894
11th to 20thNight
9%6%28%38%17%3
704
21st to endNight
6%223%39%27%4
592
March1st to 10thNight
12%328%37%17%3
720
11th to 20thNight
11%6%30%38%14%2
720
21st to endNight
14%326%37%18%3
671
April1st to 10thNight
8%7%30%35%17%3
540
11th to 20thNight
14%8%28%34%14%2
533
21st to endNight
18%7%29%33%13%1
540
May1st to 10thNight
15%428%37%15%1
540
11th to 20thNight
13%6%28%34%18%2
531
21st to endNight
17%6%22%32%19%3
410
June1st to 10thNight
14%5%27%35%18%2
360
11th to 20thNight
22%6%21%27%21%3
360
21st to endNight
12%420%41%22%2
360
July1st to 10thNight
7%420%41%27%1
350
11th to 20thNight
12%321%45%18%2
348
21st to endNight
4325%34%31%3
443
August1st to 10thNight
6%320%39%27%4
537
11th to 20thNight
9%216%45%24%3
534
21st to endNight
11%424%36%23%2
594
September1st to 10thNight
12%328%38%18%2
540
11th to 20thNight
17%5%19%41%17%1
540
21st to endNight
10%5%33%39%12%1
641
October1st to 10thNight
18%6%24%39%13%1
720
11th to 20thNight
12%5%29%37%15%2
753
21st to endNight
16%7%33%31%13%1
990
November1st to 10thNight
22%5%29%35%8%1
925
11th to 20thNight
14%6%33%33%12%3
950
21st to endNight
12%6%36%35%9%2
950
December1st to 10thNight
10%430%37%17%3
950
11th to 20thNight
13%7%32%31%15%2
950
21st to endNight
10%226%36%20%5%
1045
Page generated at 2024-02-02 04:20:30. Version ac07

Copyright 2024 Attilla Danko


Rosthern Clear Sky Chart |Charts Home