Owatonna
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Owatonna clear sky chart from 2005-11-05 to 2017-09-21.

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
35%
16109
17%
46925
9%
16062
42%
16062
25%
30907

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 15thNight
26%
900
12%
2506
5%
895
32%
895
19%
1841
January16th to endNight
22%
960
13%
2523
5%
960
28%
960
17%
1895
February1st to 15thNight
25%
879
14%
2288
4%
875
31%
875
21%
1670
February16th to endNight
28%
744
17%
2006
5%
744
37%
744
24%
1383
March1st to 15thNight
30%
576
17%
2016
10%
576
38%
576
22%
1268
March16th to endNight
30%
576
14%
2100
11%
576
38%
576
16%
1445
April1st to 15thNight
31%
539
17%
1797
11%
539
42%
539
22%
1166
April16th to endNight
29%
540
17%
1686
11%
540
38%
540
18%
1188
May1st to 15thNight
34%
540
16%
1512
9%
540
39%
540
26%
1004
May16th to endNight
40%
563
16%
1497
6%
561
46%
561
31%
972
June1st to 15thNight
47%
540
15%
1440
5%
540
51%
540
32%
925
June16th to endNight
54%
540
18%
1440
8%
540
58%
540
44%
831
July1st to 15thNight
60%
510
16%
1360
7%
510
63%
510
48%
752
July16th to endNight
67%
564
23%
1457
15%
531
70%
531
48%
791
August1st to 15thNight
62%
539
23%
1610
21%
536
66%
536
39%
896
August16th to endNight
58%
573
22%
1803
21%
573
64%
573
38%
992
September1st to 15thNight
59%
540
25%
1800
24%
540
65%
540
38%
947
September16th to endNight
43%
551
22%
1877
13%
551
54%
551
31%
1044
October1st to 15thNight
37%
660
25%
1980
15%
660
45%
660
31%
1188
October16th to endNight
33%
704
18%
2112
9%
704
41%
704
23%
1377
November1st to 15thNight
29%
811
21%
2387
9%
811
40%
811
26%
1508
November16th to endNight
25%
900
16%
2520
8%
900
32%
900
20%
1779
December1st to 15thNight
22%
900
10%
2520
3%
900
28%
900
16%
1902
December16th to endNight
18%
960
12%
2688
4%
960
26%
960
13%
2143

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
13%8%36%5%3445%7%36%
47942
Night
12%8%36%5%34446%40%
47098
Cloud CoverDay
26%7%25%423446%31%
47953
Night
25%6%25%423345%35%
47102
Cloud CoverDay
14%8%36%5%3445%7%36%
47951
Night
12%8%36%5%34446%40%
47102
TransparencyDay
46%414%23%9%
47632
Night
44%313%24%12%1
46926
SeeingDay
17%7%29%28%14%3
6117
Night
16%8%32%30%11%1
16110

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 15thDay
7%12%7%9%9%46%6%46%24%
1432
16th to endDay
9%14%7%11%9%35%5%6%6%19%
1701
February1st to 15thDay
9%12%6%11%8%37%5%6%5%23%
1575
16th to endDay
14%8%47%6%37%6%6%7%29%
1467
March1st to 15thDay
16%11%5%6%5%345%5%6%29%
1945
16th to endDay
18%10%37%425%5%46%30%
2124
April1st to 15thDay
17%9%46%5%3335%6%32%
2151
16th to endDay
23%11%46%5%24345%28%
2271
May1st to 15thDay
19%7%36%5%35%5%5%7%30%
2437
16th to endDay
16%5%35%42445%8%38%
2617
June1st to 15thDay
15%5%25%435%45%7%40%
2520
16th to endDay
10%4245%345%7%10%41%
2520
July1st to 15thDay
6%213425%5%6%10%50%
2520
16th to endDay
7%3145%35%6%6%10%44%
2610
August1st to 15thDay
8%5%26%5%35%5%7%8%42%
2340
16th to endDay
11%5%25%42445%8%45%
2399
September1st to 15thDay
11%5%2443345%7%47%
2160
16th to endDay
14%6%36%42345%7%42%
1860
October1st to 15thDay
15%7%24424345%45%
1650
16th to endDay
18%10%36%423345%38%
1758
November1st to 15thDay
11%10%45%324446%41%
1469
16th to endDay
13%11%46%5%3435%7%33%
1440
December1st to 15thDay
16%10%5%8%9%5%5%5%45%22%
1440
16th to endDay
19%15%7%9%6%35%335%19%
1536
January1st to 15thNight
10%9%5%8%7%46%6%5%6%30%
2506
16th to endNight
11%11%5%11%6%445%6%6%26%
2523
February1st to 15thNight
9%13%5%8%6%34446%33%
2285
16th to endNight
9%8%36%7%35%45%6%37%
2006
March1st to 15thNight
13%9%445%23346%40%
2004
16th to endNight
16%9%47%5%25%445%34%
2100
April1st to 15thNight
16%9%35%4145%5%5%39%
1797
16th to endNight
23%10%35%42334434%
1686
May1st to 15thNight
17%6%345%23236%43%
1512
16th to endNight
12%6%25%335%36%9%40%
1496
June1st to 15thNight
10%425%5%3445%9%44%
1440
16th to endNight
7%31433335%9%54%
1440
July1st to 15thNight
4212325%45%8%58%
1440
16th to endNight
4213324448%58%
1556
August1st to 15thNight
5%3245%25%45%8%52%
1620
16th to endNight
9%423313346%55%
1803
September1st to 15thNight
9%314322445%57%
1800
16th to endNight
11%5%24422347%51%
1877
October1st to 15thNight
15%5%14422335%49%
1980
16th to endNight
17%7%35%323346%40%
2112
November1st to 15thNight
12%8%26%424435%44%
2387
16th to endNight
13%11%47%6%23346%35%
2520
December1st to 15thNight
13%10%5%8%7%5%5%446%28%
2520
16th to endNight
17%13%5%11%6%35%34422%
2688

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 15thDay
22%8%47%9%35%5%45%21%
1432
16th to endDay
24%13%410%7%35%45%5%15%
1701
February1st to 15thDay
23%10%49%7%4444422%
1575
16th to endDay
26%7%37%5%25%45%6%24%
1467
March1st to 15thDay
28%9%36%424445%26%
1956
16th to endDay
30%9%36%42443426%
2124
April1st to 15thDay
31%8%345%33345%27%
2151
16th to endDay
36%11%25%42333422%
2271
May1st to 15thDay
32%6%15%5%23446%25%
2437
16th to endDay
32%5%15%322346%32%
2617
June1st to 15thDay
31%424423445%33%
2520
16th to endDay
26%41342345%7%35%
2520
July1st to 15thDay
23%213424447%41%
2520
16th to endDay
24%3144245%5%8%36%
2610
August1st to 15thDay
17%415%4345%6%7%39%
2340
16th to endDay
18%5%1442445%6%43%
2399
September1st to 15thDay
17%5%1342345%7%44%
2160
16th to endDay
21%5%24323447%39%
1860
October1st to 15thDay
24%6%2432234442%
1650
16th to endDay
25%9%25%322245%35%
1758
November1st to 15thDay
24%8%25%31333437%
1469
16th to endDay
28%8%26%323335%32%
1440
December1st to 15thDay
31%7%47%7%43435%18%
1440
16th to endDay
31%14%5%9%5%3322416%
1536
January1st to 15thNight
24%7%36%6%35%5%45%26%
2506
16th to endNight
26%10%49%5%335%5%5%21%
2523
February1st to 15thNight
24%11%48%5%23235%29%
2278
16th to endNight
22%7%25%6%3435%5%32%
2006
March1st to 15thNight
26%8%25%322335%35%
2016
16th to endNight
29%8%26%423335%29%
2100
April1st to 15thNight
31%7%2332334433%
1797
16th to endNight
35%9%2432234327%
1686
May1st to 15thNight
32%414412135%37%
1511
16th to endNight
29%5%24323346%34%
1496
June1st to 15thNight
25%3245%23346%37%
1440
16th to endNight
23%23322337%45%
1440
July1st to 15thNight
21%2232335%6%48%
1440
16th to endNight
20%23323346%49%
1556
August1st to 15thNight
14%31442345%7%49%
1620
16th to endNight
16%313322245%53%
1803
September1st to 15thNight
16%214313335%53%
1800
16th to endNight
18%414322237%48%
1877
October1st to 15thNight
22%5%13322425%45%
1980
16th to endNight
25%6%24323335%38%
2112
November1st to 15thNight
24%7%25%32233439%
2387
16th to endNight
26%9%35%5%12235%32%
2520
December1st to 15thNight
28%9%37%5%34435%23%
2520
16th to endNight
30%12%410%5%3223319%
2688

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 15thDay
8%11%7%9%9%47%5%46%23%
1432
16th to endDay
9%14%6%12%9%46%5%6%6%19%
1701
February1st to 15thDay
9%12%6%11%7%46%6%5%5%23%
1575
16th to endDay
14%8%47%6%36%6%5%7%29%
1467
March1st to 15thDay
15%11%47%43445%7%29%
1956
16th to endDay
18%10%46%5%25%5%46%31%
2122
April1st to 15thDay
17%9%46%5%3336%6%32%
2151
16th to endDay
23%11%46%5%24436%28%
2271
May1st to 15thDay
19%7%36%6%35%45%7%30%
2437
16th to endDay
16%6%25%42345%8%38%
2617
June1st to 15thDay
15%5%25%5%25%35%7%40%
2520
16th to endDay
11%5%244345%6%9%42%
2520
July1st to 15thDay
7%2234245%6%10%49%
2520
16th to endDay
8%325%4346%7%10%44%
2610
August1st to 15thDay
9%425%5%45%5%7%8%42%
2340
16th to endDay
11%5%25%43445%7%46%
2399
September1st to 15thDay
11%5%2442445%7%47%
2160
16th to endDay
14%6%25%5%2345%7%42%
1860
October1st to 15thDay
16%7%24423345%45%
1650
16th to endDay
18%10%36%32235%5%38%
1758
November1st to 15thDay
11%11%35%324446%41%
1469
16th to endDay
13%10%47%5%34446%34%
1440
December1st to 15thDay
16%9%5%8%9%5%5%5%36%22%
1440
16th to endDay
19%16%6%10%6%45%245%18%
1536
January1st to 15thNight
10%9%5%7%7%36%6%46%30%
2506
16th to endNight
11%11%5%11%6%445%5%6%26%
2523
February1st to 15thNight
9%12%6%8%6%34346%33%
2278
16th to endNight
10%8%36%6%45%45%6%37%
2006
March1st to 15thNight
13%9%45%42435%6%41%
2016
16th to endNight
16%9%46%5%34446%34%
2100
April1st to 15thNight
16%9%25%42345%6%39%
1797
16th to endNight
22%10%35%42234434%
1686
May1st to 15thNight
18%5%25%5%23236%43%
1511
16th to endNight
12%6%35%32446%8%41%
1496
June1st to 15thNight
10%4245%3445%9%44%
1440
16th to endNight
8%31342335%9%54%
1440
July1st to 15thNight
421332445%8%58%
1440
16th to endNight
5%31342345%8%58%
1556
August1st to 15thNight
5%324425%45%8%52%
1620
16th to endNight
9%414323346%55%
1803
September1st to 15thNight
10%314323345%57%
1800
16th to endNight
11%5%24422338%50%
1877
October1st to 15thNight
15%5%24323336%49%
1980
16th to endNight
18%7%35%334346%40%
2112
November1st to 15thNight
12%8%35%5%24335%44%
2387
16th to endNight
13%11%5%6%6%23346%36%
2520
December1st to 15thNight
13%11%48%7%45%45%6%27%
2520
16th to endNight
18%13%5%11%6%44345%22%
2688

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 15thDay
59%410%16%7%
1433
16th to endDay
63%313%14%4
1701
February1st to 15thDay
60%312%16%5%
1576
16th to endDay
52%412%23%6%
1467
March1st to 15thDay
53%414%20%6%
1956
16th to endDay
54%314%21%4
2124
April1st to 15thDay
52%311%23%9%1
2151
16th to endDay
58%313%17%6%1
2271
May1st to 15thDay
52%5%14%22%5%
2437
16th to endDay
43%415%23%11%1
2621
June1st to 15thDay
41%415%26%10%
2520
16th to endDay
36%417%27%12%1
2520
July1st to 15thDay
30%5%16%32%13%1
2371
16th to endDay
32%5%17%26%15%1
2446
August1st to 15thDay
37%5%14%29%11%1
2326
16th to endDay
36%5%15%28%13%1
2399
September1st to 15thDay
34%5%13%32%13%
2160
16th to endDay
41%413%29%10%
1860
October1st to 15thDay
41%312%25%15%1
1650
16th to endDay
48%215%24%8%
1758
November1st to 15thDay
42%413%22%15%1
1469
16th to endDay
50%418%18%8%
1440
December1st to 15thDay
62%5%14%11%5%
1440
16th to endDay
68%29%14%4
1536
January1st to 15thNight
52%5%13%19%8%
2506
16th to endNight
56%315%17%6%
2523
February1st to 15thNight
53%312%21%8%
2288
16th to endNight
46%312%24%11%1
2006
March1st to 15thNight
44%314%25%10%1
2016
16th to endNight
51%413%23%6%
2100
April1st to 15thNight
46%310%24%14%1
1797
16th to endNight
52%39%18%12%2
1686
May1st to 15thNight
43%414%23%12%1
1512
16th to endNight
39%314%25%14%1
1498
June1st to 15thNight
36%5%12%30%12%1
1440
16th to endNight
27%315%30%20%2
1440
July1st to 15thNight
24%315%35%18%2
1360
16th to endNight
22%5%15%34%18%4
1457
August1st to 15thNight
28%413%31%18%2
1610
16th to endNight
29%315%29%18%3
1803
September1st to 15thNight
28%312%32%23%
1800
16th to endNight
34%213%31%16%
1877
October1st to 15thNight
37%210%29%15%3
1980
16th to endNight
45%314%23%13%
2112
November1st to 15thNight
41%212%23%17%1
2387
16th to endNight
50%315%21%8%1
2520
December1st to 15thNight
56%5%13%18%5%
2520
16th to endNight
65%210%14%6%
2688

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 15thDay
23%5%41%23%42
90
16th to endDay
17%11%37%28%41
96
February1st to 15thDay
11%17%43%25%2
90
16th to endDay
27%6%25%30%9%
81
March1st to 15thDay
23%12%37%25%1
90
16th to endDay
36%5%32%17%7%
108
April1st to 15thDay
21%11%32%25%8%
270
16th to endDay
32%11%25%18%9%1
381
May1st to 15thDay
23%11%33%22%7%2
468
16th to endDay
21%8%29%24%13%2
517
June1st to 15thDay
14%7%26%33%13%4
495
16th to endDay
13%6%31%29%15%3
495
July1st to 15thDay
5%328%34%20%8%
475
16th to endDay
10%323%34%22%5%
515
August1st to 15thDay
10%122%35%24%5%
493
16th to endDay
15%423%29%19%7%
439
September1st to 15thDay
11%5%28%29%20%5%
315
16th to endDay
19%6%34%21%10%6%
147
October1st to 15thDay
6%13%33%24%17%4
90
16th to endDay
28%9%36%16%8%1
96
November1st to 15thDay
7%335%41%10%2
90
16th to endDay
33%14%32%15%4
90
December1st to 15thDay
23%14%34%26%1
90
16th to endDay
34%16%33%13%2
96
January1st to 15thNight
14%12%38%25%8%
900
16th to endNight
19%10%37%27%5%
960
February1st to 15thNight
15%11%38%26%6%1
880
16th to endNight
14%10%39%25%9%
744
March1st to 15thNight
19%8%36%24%11%
576
16th to endNight
20%8%31%26%10%1
576
April1st to 15thNight
20%10%34%28%5%
539
16th to endNight
29%7%28%26%6%1
540
May1st to 15thNight
21%7%32%29%7%
540
16th to endNight
16%5%30%34%12%
563
June1st to 15thNight
13%328%40%13%
540
16th to endNight
10%228%45%13%
540
July1st to 15thNight
6%125%36%26%2
510
16th to endNight
5%218%47%22%2
564
August1st to 15thNight
7%120%41%25%3
539
16th to endNight
11%122%38%21%3
573
September1st to 15thNight
12%220%39%19%4
540
16th to endNight
13%6%30%29%17%1
551
October1st to 15thNight
18%6%34%24%14%1
660
16th to endNight
22%9%28%30%8%
704
November1st to 15thNight
17%11%36%24%8%
811
16th to endNight
20%13%36%21%8%
900
December1st to 15thNight
19%9%40%24%5%
900
16th to endNight
24%10%32%25%7%
960
Page generated at 2017-09-22 06:35:29. Version ac04

Copyright 2017 A. Danko


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