Whitefish
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Whitefish clear sky chart from 2005-11-06 to 2024-02-25.

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
30%
23680
14%
80908
8%
23584
38%
23584
17%
56481

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
19%
943
9%
4707
5%
926
26%
926
7%
3565
January11th to 20thNight
20%
946
10%
4467
4%
930
27%
930
8%
3179
January21st to endNight
25%
929
8%
4694
6%
919
31%
919
7%
3688
February1st to 10thNight
20%
760
14%
2470
6%
760
30%
760
12%
1813
February11th to 20thNight
22%
741
15%
2403
6%
739
32%
739
14%
1707
February21st to endNight
19%
611
14%
1865
5%
611
29%
611
14%
1390
March1st to 10thNight
22%
720
17%
2078
7%
720
32%
720
20%
1409
March11th to 20thNight
24%
720
18%
1980
7%
720
33%
720
21%
1377
March21st to endNight
28%
792
19%
2178
8%
792
37%
792
24%
1467
April1st to 10thNight
28%
671
16%
1855
7%
671
34%
671
20%
1316
April11th to 20thNight
32%
533
22%
1597
10%
533
41%
533
22%
1055
April21st to endNight
30%
540
16%
1620
8%
540
36%
540
18%
1134
May1st to 10thNight
35%
540
16%
1620
10%
540
42%
540
23%
1076
May11th to 20thNight
41%
406
20%
1467
16%
406
53%
406
22%
891
May21st to endNight
40%
389
16%
1451
13%
388
52%
388
26%
846
June1st to 10thNight
36%
360
14%
1260
11%
360
44%
360
23%
774
June11th to 20thNight
41%
360
16%
1260
14%
360
49%
360
25%
741
June21st to endNight
42%
360
14%
1260
11%
360
49%
360
24%
764
July1st to 10thNight
50%
350
19%
1225
15%
350
59%
350
36%
635
July11th to 20thNight
54%
348
20%
1218
20%
348
60%
348
31%
692
July21st to endNight
48%
588
15%
1557
10%
556
52%
556
33%
966
August1st to 10thNight
54%
537
17%
1600
12%
534
59%
534
32%
958
August11th to 20thNight
53%
534
19%
1598
13%
534
60%
534
32%
977
August21st to endNight
46%
594
19%
1782
11%
594
53%
594
29%
1104
September1st to 10thNight
44%
674
19%
1793
11%
674
48%
674
32%
1121
September11th to 20thNight
45%
720
24%
1980
13%
720
52%
720
36%
1180
September21st to endNight
41%
720
20%
1980
13%
720
46%
720
26%
1335
October1st to 10thNight
36%
720
18%
2119
12%
720
43%
720
23%
1417
October11th to 20thNight
25%
720
17%
2160
8%
720
37%
720
16%
1566
October21st to endNight
22%
792
13%
2508
8%
792
31%
792
13%
1869
November1st to 10thNight
27%
740
18%
2464
12%
740
37%
740
17%
1673
November11th to 20thNight
24%
760
13%
2660
8%
760
33%
760
12%
1932
November21st to endNight
18%
760
11%
2660
5%
760
26%
760
10%
2016
December1st to 10thNight
18%
813
11%
2713
4%
813
26%
813
10%
2088
December11th to 20thNight
18%
950
12%
3476
4%
948
26%
948
11%
2555
December21st to endNight
15%
1039
6%
5183
2%
1026
21%
1026
5%
4205

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
16%10%47%6%3445%7%34%
78052
Night
16%11%48%6%3445%6%32%
81268
TransparencyDay
51%311%22%11%1
77753
Night
54%311%21%10%1
81103
SeeingDay
23%13%32%22%8%3
14275
Night
22%11%28%27%10%1
23711

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
17%19%9%11%6%3323422%
2208
11th to 20thDay
11%13%7%14%11%5%6%445%19%
2472
21st to endDay
16%22%9%11%7%345%4415%
2944
February1st to 10thDay
11%16%6%10%8%5%45%46%26%
1710
11th to 20thDay
13%14%5%10%7%345%46%29%
1663
21st to endDay
12%16%6%11%8%44445%26%
1483
March1st to 10thDay
14%12%46%5%25%5%46%37%
1878
11th to 20thDay
13%10%5%7%6%34445%38%
1980
21st to endDay
16%10%36%6%34445%38%
2178
April1st to 10thDay
19%12%47%5%4445%6%30%
2118
11th to 20thDay
20%10%35%43445%6%36%
2312
21st to endDay
22%9%35%5%2435%6%36%
2340
May1st to 10thDay
17%8%36%6%3445%6%37%
2340
11th to 20thDay
16%8%36%5%335%5%7%39%
2424
21st to endDay
15%5%24435%46%9%43%
2822
June1st to 10thDay
16%7%36%5%35%45%8%39%
2700
11th to 20thDay
13%6%35%6%35%5%6%8%40%
2700
21st to endDay
17%6%35%6%35%5%6%7%39%
2700
July1st to 10thDay
10%5%25%435%46%9%46%
2700
11th to 20thDay
11%5%25%6%46%5%6%8%41%
2700
21st to endDay
12%5%25%5%35%5%6%9%43%
2665
August1st to 10thDay
14%6%25%5%35%5%5%10%40%
2327
11th to 20thDay
14%5%345%35%5%6%8%42%
2303
21st to endDay
13%6%26%5%36%5%5%8%42%
2574
September1st to 10thDay
13%6%36%6%35%45%8%41%
2147
11th to 20thDay
14%6%235%45%5%5%8%43%
1980
21st to endDay
21%6%36%5%345%46%37%
1980
October1st to 10thDay
20%7%35%5%3445%7%37%
1841
11th to 20thDay
26%8%36%7%45%5%5%6%25%
1800
21st to endDay
26%11%38%43446%6%25%
1846
November1st to 10thDay
18%12%36%5%3446%7%30%
1612
11th to 20thDay
17%13%7%8%6%45%45%6%26%
1520
21st to endDay
23%19%5%8%5%44345%19%
1520
December1st to 10thDay
13%22%6%8%6%345%5%5%23%
1463
11th to 20thDay
19%16%6%8%6%34445%25%
1671
21st to endDay
27%20%6%9%5%3333417%
2431
January1st to 10thNight
15%15%8%12%7%34446%20%
4748
11th to 20thNight
13%14%5%11%8%35%6%6%6%23%
4495
21st to endNight
15%19%7%10%7%45%445%19%
4715
February1st to 10thNight
12%14%5%11%6%46%5%5%5%26%
2470
11th to 20thNight
12%13%5%10%7%346%5%6%29%
2403
21st to endNight
13%16%6%9%6%35%5%46%26%
1865
March1st to 10thNight
12%11%47%6%3445%6%37%
2068
11th to 20thNight
14%9%5%7%7%35%45%5%36%
1979
21st to endNight
17%8%36%5%4435%6%40%
2178
April1st to 10thNight
20%9%36%5%445%5%6%34%
1855
11th to 20thNight
18%9%35%43445%6%40%
1597
21st to endNight
20%8%39%6%34445%35%
1620
May1st to 10thNight
13%8%27%6%35%6%5%7%37%
1620
11th to 20thNight
12%8%35%445%5%5%8%40%
1467
21st to endNight
11%6%46%5%24448%46%
1450
June1st to 10thNight
13%5%36%5%35%6%7%7%39%
1260
11th to 20thNight
12%5%35%445%5%6%9%43%
1260
21st to endNight
13%5%36%5%45%46%8%42%
1260
July1st to 10thNight
9%4245%335%6%8%52%
1260
11th to 20thNight
9%5%25%5%35%6%5%8%48%
1260
21st to endNight
10%425%6%35%5%5%8%46%
1648
August1st to 10thNight
10%5%25%445%5%6%7%47%
1611
11th to 20thNight
12%5%26%6%3445%8%47%
1598
21st to endNight
14%5%25%435%45%8%45%
1782
September1st to 10thNight
13%5%25%5%3445%7%46%
1793
11th to 20thNight
14%414324448%51%
1980
21st to endNight
17%8%36%5%3445%7%40%
1980
October1st to 10thNight
21%7%35%43345%7%39%
2119
11th to 20thNight
25%9%36%5%34446%31%
2160
21st to endNight
26%10%37%5%345%5%427%
2508
November1st to 10thNight
18%11%36%5%25%46%7%33%
2464
11th to 20thNight
18%12%48%6%45%45%7%26%
2660
21st to endNight
21%16%5%7%5%3445%5%24%
2660
December1st to 10thNight
17%17%7%8%6%35%445%23%
2713
11th to 20thNight
18%15%5%8%6%34446%27%
3526
21st to endNight
25%20%6%10%5%23335%17%
5236

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
69%112%12%5%
2209
11th to 20thDay
68%212%12%41
2472
21st to endDay
73%28%10%7%1
2944
February1st to 10thDay
61%211%18%7%1
1710
11th to 20thDay
57%310%18%11%2
1672
21st to endDay
63%26%19%10%1
1483
March1st to 10thDay
49%314%15%16%2
1881
11th to 20thDay
49%28%27%10%3
1980
21st to endDay
50%210%22%13%3
2178
April1st to 10thDay
56%211%18%12%1
2118
11th to 20thDay
50%27%25%14%2
2312
21st to endDay
50%29%21%15%4
2340
May1st to 10thDay
47%310%23%14%4
2340
11th to 20thDay
45%38%23%19%2
2428
21st to endDay
40%315%25%15%2
2822
June1st to 10thDay
45%211%26%15%2
2700
11th to 20thDay
42%311%25%18%1
2700
21st to endDay
45%412%25%13%2
2700
July1st to 10thDay
34%314%29%18%1
2626
11th to 20thDay
39%411%30%14%1
2619
21st to endDay
39%412%31%14%1
2517
August1st to 10thDay
40%416%26%12%2
2314
11th to 20thDay
40%317%29%11%1
2303
21st to endDay
41%415%28%11%1
2574
September1st to 10thDay
43%412%28%12%1
2147
11th to 20thDay
39%315%31%11%
1980
21st to endDay
48%415%26%7%
1980
October1st to 10thDay
48%312%25%11%1
1841
11th to 20thDay
60%311%17%9%
1800
21st to endDay
60%213%15%8%1
1846
November1st to 10thDay
53%312%23%8%
1612
11th to 20thDay
60%311%16%9%
1520
21st to endDay
69%210%13%6%
1520
December1st to 10thDay
63%212%15%7%1
1463
11th to 20thDay
64%310%18%5%1
1671
21st to endDay
74%26%12%6%
2431
January1st to 10thNight
67%211%13%8%
4748
11th to 20thNight
62%215%16%5%
4495
21st to endNight
68%38%15%6%
4715
February1st to 10thNight
60%29%20%8%1
2470
11th to 20thNight
56%312%20%9%1
2405
21st to endNight
60%210%17%9%1
1865
March1st to 10thNight
49%212%21%15%2
2078
11th to 20thNight
51%211%21%14%2
1980
21st to endNight
47%211%19%17%4
2178
April1st to 10thNight
53%28%21%15%2
1855
11th to 20thNight
46%35%26%18%2
1597
21st to endNight
54%18%19%15%3
1620
May1st to 10thNight
46%49%24%13%4
1620
11th to 20thNight
42%46%27%19%3
1468
21st to endNight
38%412%27%15%4
1451
June1st to 10thNight
42%410%25%16%2
1260
11th to 20thNight
39%311%25%19%2
1260
21st to endNight
41%414%26%13%2
1260
July1st to 10thNight
29%314%32%19%3
1225
11th to 20thNight
34%412%32%17%1
1218
21st to endNight
37%316%27%16%1
1557
August1st to 10thNight
36%418%29%12%2
1600
11th to 20thNight
38%315%31%12%2
1598
21st to endNight
40%316%26%13%2
1782
September1st to 10thNight
38%314%31%12%3
1793
11th to 20thNight
34%315%39%9%
1980
21st to endNight
45%414%28%9%
1980
October1st to 10thNight
47%312%25%13%
2119
11th to 20thNight
56%311%22%7%
2160
21st to endNight
60%211%18%7%1
2508
November1st to 10thNight
51%312%23%10%
2464
11th to 20thNight
59%313%17%9%
2660
21st to endNight
63%312%14%7%
2660
December1st to 10thNight
65%29%19%5%
2713
11th to 20thNight
60%212%16%9%2
3525
21st to endNight
73%19%11%5%
5236

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
23%16%33%21%8%
180
11th to 20thDay
23%15%35%21%6%1
256
21st to endDay
27%10%32%23%7%1
297
February1st to 10thDay
26%20%36%13%5%
270
11th to 20thDay
23%21%40%13%2
270
21st to endDay
32%24%33%11%
210
March1st to 10thDay
25%21%31%17%5%
321
11th to 20thDay
26%13%34%20%7%1
420
21st to endDay
29%15%31%20%5%2
462
April1st to 10thDay
27%15%27%22%8%1
420
11th to 20thDay
31%17%22%18%9%2
412
21st to endDay
32%14%29%15%8%2
420
May1st to 10thDay
21%13%35%21%7%4
423
11th to 20thDay
23%16%28%22%8%4
447
21st to endDay
19%12%35%24%8%2
582
June1st to 10thDay
18%16%37%22%6%1
630
11th to 20thDay
19%15%35%22%8%2
630
21st to endDay
21%14%31%23%8%2
630
July1st to 10thDay
12%14%35%28%9%2
621
11th to 20thDay
13%11%34%28%9%4
618
21st to endDay
13%7%39%26%10%5%
606
August1st to 10thDay
18%5%26%29%16%5%
446
11th to 20thDay
16%5%26%28%15%9%
439
21st to endDay
17%10%31%23%13%7%
495
September1st to 10thDay
16%9%26%29%13%6%
450
11th to 20thDay
18%7%28%29%12%5%
450
21st to endDay
26%12%24%24%11%4
450
October1st to 10thDay
27%10%28%21%11%2
450
11th to 20thDay
32%12%33%16%5%1
450
21st to endDay
34%15%34%15%11
361
November1st to 10thDay
30%15%37%13%5%1
241
11th to 20thDay
23%19%33%21%3
180
21st to endDay
32%20%26%16%6%1
180
December1st to 10thDay
28%9%36%21%5%2
180
11th to 20thDay
31%17%36%13%3
180
21st to endDay
37%18%29%12%41
198
January1st to 10thNight
24%13%31%25%7%1
950
11th to 20thNight
26%15%25%26%7%1
950
21st to endNight
22%9%30%28%10%1
941
February1st to 10thNight
19%16%34%25%5%
760
11th to 20thNight
21%14%34%24%6%1
743
21st to endNight
23%16%33%22%6%
611
March1st to 10thNight
18%16%35%26%5%
720
11th to 20thNight
20%13%34%24%8%1
720
21st to endNight
22%12%32%26%7%1
792
April1st to 10thNight
24%12%30%26%6%1
671
11th to 20thNight
25%12%26%25%11%1
533
21st to endNight
24%11%25%28%11%
540
May1st to 10thNight
16%8%29%35%11%1
540
11th to 20thNight
17%9%28%34%12%
406
21st to endNight
14%7%33%32%14%
389
June1st to 10thNight
17%8%34%34%8%
360
11th to 20thNight
15%6%30%37%12%
360
21st to endNight
18%5%27%35%14%1
360
July1st to 10thNight
9%5%29%44%12%1
350
11th to 20thNight
11%426%43%16%
348
21st to endNight
12%5%27%37%18%2
588
August1st to 10thNight
14%222%40%21%1
537
11th to 20thNight
14%219%37%23%4
534
21st to endNight
17%5%24%30%22%2
594
September1st to 10thNight
16%7%25%32%18%3
674
11th to 20thNight
16%9%26%29%16%3
720
21st to endNight
21%7%25%28%18%2
720
October1st to 10thNight
24%7%26%31%10%2
720
11th to 20thNight
31%10%27%23%8%1
720
21st to endNight
32%12%27%23%41
792
November1st to 10thNight
26%11%28%25%8%
740
11th to 20thNight
27%14%26%24%8%
760
21st to endNight
32%13%28%22%5%1
760
December1st to 10thNight
28%14%30%21%7%
813
11th to 20thNight
28%15%30%20%6%1
950
21st to endNight
33%13%27%20%7%
1045
Page generated at 2024-02-22 06:05:44. Version ac07

Copyright 2024 Attilla Danko


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