Estherville
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Estherville clear sky chart from 2005-11-05 to 2019-06-24.

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
36%
18527
18%
53966
9%
18480
44%
18480
26%
35133

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
28%
1050
15%
2857
6%
1045
36%
1045
22%
2002
January16th to endNight
24%
1120
15%
2912
5%
1120
32%
1120
19%
2132
February1st to 15thNight
23%
1029
12%
2678
3%
1025
29%
1025
19%
1987
February16th to endNight
27%
881
17%
2351
4%
881
36%
881
23%
1638
March1st to 15thNight
32%
630
18%
2310
10%
630
44%
630
21%
1447
March16th to endNight
29%
672
13%
2464
8%
672
37%
672
16%
1679
April1st to 15thNight
29%
629
16%
2136
11%
629
39%
629
21%
1402
April16th to endNight
30%
624
18%
1885
12%
624
40%
624
21%
1316
May1st to 15thNight
37%
630
16%
1862
10%
630
43%
630
24%
1252
May16th to endNight
41%
659
15%
1754
6%
657
46%
657
28%
1188
June1st to 15thNight
51%
630
16%
1680
6%
630
55%
630
35%
1054
June16th to endNight
54%
609
18%
1538
6%
609
57%
609
43%
924
July1st to 15thNight
63%
555
20%
1476
8%
555
67%
555
51%
793
July16th to endNight
71%
612
22%
1690
17%
579
72%
579
50%
867
August1st to 15thNight
66%
575
22%
1717
21%
572
70%
572
42%
945
August16th to endNight
59%
621
23%
1912
24%
621
64%
621
38%
1057
September1st to 15thNight
58%
585
26%
1979
24%
585
67%
585
40%
997
September16th to endNight
43%
585
25%
2148
18%
585
56%
585
31%
1176
October1st to 15thNight
34%
780
24%
2340
13%
780
43%
780
28%
1427
October16th to endNight
35%
832
21%
2496
11%
832
44%
832
28%
1531
November1st to 15thNight
33%
999
23%
2765
10%
999
43%
999
27%
1776
November16th to endNight
27%
1050
18%
2940
8%
1050
35%
1050
24%
1968
December1st to 15thNight
23%
1050
12%
2940
4%
1050
30%
1050
18%
2185
December16th to endNight
20%
1120
14%
3136
5%
1120
29%
1120
15%
2390

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%7%36%5%3445%7%38%
54818
Night
11%7%35%42445%6%42%
54146
Cloud CoverDay
13%7%36%5%3445%7%38%
54829
Night
11%7%35%42445%6%43%
54150
Cloud CoverDay
13%7%36%5%3445%7%38%
54827
Night
11%7%35%5%3445%7%42%
54150
TransparencyDay
45%5%13%22%11%1
54516
Night
41%5%13%24%13%1
53966
SeeingDay
17%7%29%28%13%3
8428
Night
15%8%33%30%11%
18528

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
8%11%5%8%7%4446%7%30%
1739
16th to endDay
9%12%6%10%7%36%5%5%7%24%
2016
February1st to 15thDay
11%10%6%9%8%36%446%27%
1845
16th to endDay
13%9%48%8%35%447%30%
1707
March1st to 15thDay
14%11%6%7%5%34345%33%
2299
16th to endDay
16%11%46%5%35%46%6%28%
2464
April1st to 15thDay
19%7%37%5%2446%8%31%
2472
16th to endDay
24%10%35%423345%30%
2676
May1st to 15thDay
21%7%36%5%34346%34%
2749
16th to endDay
17%5%25%43445%7%38%
3065
June1st to 15thDay
14%5%245%3445%9%40%
2940
16th to endDay
10%5%245%35%5%6%8%42%
2897
July1st to 15thDay
6%214425%5%5%10%50%
2730
16th to endDay
5%3144245%7%9%51%
2721
August1st to 15thDay
8%5%25%5%45%5%6%8%41%
2486
16th to endDay
11%6%245%245%5%6%45%
2642
September1st to 15thDay
12%42333345%7%49%
2308
16th to endDay
12%6%1432335%6%49%
2129
October1st to 15thDay
15%8%25%423335%43%
1950
16th to endDay
13%8%25%423335%45%
2080
November1st to 15thDay
11%7%36%5%2345%6%43%
1751
16th to endDay
12%9%5%6%6%24338%36%
1680
December1st to 15thDay
12%11%411%9%46%346%25%
1680
16th to endDay
17%12%5%9%7%2445%8%23%
1792
January1st to 15thNight
8%8%46%6%45%5%7%9%32%
2857
16th to endNight
10%11%47%6%445%5%8%30%
2912
February1st to 15thNight
11%12%5%7%5%3445%5%33%
2675
16th to endNight
11%8%37%6%35%446%37%
2351
March1st to 15thNight
12%8%36%5%24447%41%
2298
16th to endNight
15%10%37%5%25%346%34%
2464
April1st to 15thNight
17%7%25%424445%40%
2136
16th to endNight
19%8%35%5%34235%38%
1885
May1st to 15thNight
16%5%24434436%42%
1862
16th to endNight
14%5%25%4245%6%9%39%
1752
June1st to 15thNight
9%3244246%6%8%46%
1680
16th to endNight
8%21432345%8%55%
1538
July1st to 15thNight
321322335%8%62%
1556
16th to endNight
211132446%10%61%
1797
August1st to 15thNight
5%3144235%5%8%56%
1727
16th to endNight
8%414323246%57%
1912
September1st to 15thNight
9%313313246%60%
1979
16th to endNight
9%42432435%6%53%
2148
October1st to 15thNight
16%6%1442323449%
2340
16th to endNight
14%7%2332335%5%48%
2496
November1st to 15thNight
12%7%25%433345%46%
2765
16th to endNight
10%8%47%5%24446%41%
2940
December1st to 15thNight
12%11%38%6%45%5%46%30%
2940
16th to endNight
17%10%5%9%7%34345%28%
3136

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
8%11%47%8%45%46%7%30%
1739
16th to endDay
10%11%6%10%8%46%46%6%24%
2016
February1st to 15thDay
11%10%6%10%7%45%446%27%
1845
16th to endDay
13%9%48%7%35%446%31%
1707
March1st to 15thDay
14%10%6%7%434345%33%
2310
16th to endDay
17%11%46%6%3445%7%28%
2464
April1st to 15thDay
19%7%37%5%2446%7%31%
2472
16th to endDay
24%10%24424345%30%
2676
May1st to 15thDay
22%7%25%5%34346%34%
2749
16th to endDay
17%5%25%43445%7%38%
3065
June1st to 15thDay
14%5%15%5%3445%8%41%
2940
16th to endDay
11%4245%35%5%5%8%43%
2897
July1st to 15thDay
6%213435%5%5%10%50%
2730
16th to endDay
5%3144245%6%9%51%
2721
August1st to 15thDay
8%5%25%6%35%5%6%8%41%
2486
16th to endDay
12%5%25%4345%5%7%45%
2642
September1st to 15thDay
12%41332345%7%49%
2308
16th to endDay
13%5%2442235%6%49%
2129
October1st to 15thDay
15%7%25%5%23335%44%
1950
16th to endDay
13%9%25%423346%45%
2080
November1st to 15thDay
11%7%26%5%23446%44%
1751
16th to endDay
12%9%46%6%34338%36%
1680
December1st to 15thDay
12%10%411%9%37%436%25%
1680
16th to endDay
17%12%5%8%6%3435%7%23%
1792
January1st to 15thNight
8%8%46%6%46%5%7%9%33%
2857
16th to endNight
10%11%48%5%445%5%7%31%
2912
February1st to 15thNight
11%12%5%8%6%2445%5%33%
2668
16th to endNight
11%8%36%6%34446%37%
2351
March1st to 15thNight
12%7%36%423447%41%
2310
16th to endNight
15%10%46%5%35%35%6%35%
2464
April1st to 15thNight
17%7%26%424445%40%
2136
16th to endNight
19%8%36%424335%38%
1885
May1st to 15thNight
16%6%15%5%34436%42%
1861
16th to endNight
14%5%25%5%245%6%9%40%
1752
June1st to 15thNight
9%4244246%6%8%46%
1680
16th to endNight
8%21332445%8%55%
1538
July1st to 15thNight
321332335%9%62%
1556
16th to endNight
311222446%10%61%
1797
August1st to 15thNight
5%31442445%8%56%
1727
16th to endNight
9%413333245%58%
1912
September1st to 15thNight
9%313322336%60%
1979
16th to endNight
9%423324346%53%
2148
October1st to 15thNight
16%5%2432333450%
2340
16th to endNight
14%7%23322346%48%
2496
November1st to 15thNight
12%7%25%423345%46%
2765
16th to endNight
10%8%46%5%24346%41%
2940
December1st to 15thNight
12%11%38%6%35%5%5%6%30%
2940
16th to endNight
17%10%6%8%7%33445%28%
3136

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%10%5%8%8%4446%7%30%
1739
16th to endDay
10%11%6%9%8%46%6%5%6%24%
2016
February1st to 15thDay
11%11%6%9%7%45%446%27%
1845
16th to endDay
13%9%48%8%35%5%47%29%
1707
March1st to 15thDay
15%10%7%7%434245%33%
2310
16th to endDay
16%10%47%5%345%5%7%28%
2462
April1st to 15thDay
18%7%37%5%2445%8%31%
2472
16th to endDay
24%11%25%423445%30%
2676
May1st to 15thDay
21%7%36%5%34346%34%
2749
16th to endDay
16%6%25%434447%38%
3065
June1st to 15thDay
14%5%25%5%2445%9%40%
2940
16th to endDay
10%425%5%35%5%6%8%42%
2897
July1st to 15thDay
5%214435%5%5%10%50%
2730
16th to endDay
5%3144245%6%11%50%
2721
August1st to 15thDay
8%5%25%6%45%5%6%8%41%
2486
16th to endDay
11%6%25%4245%5%6%45%
2642
September1st to 15thDay
12%42342445%7%49%
2308
16th to endDay
12%6%23423446%49%
2129
October1st to 15thDay
14%8%25%5%2334444%
1950
16th to endDay
13%9%25%423336%45%
2080
November1st to 15thDay
11%7%26%5%2345%6%43%
1751
16th to endDay
12%9%5%5%6%34338%36%
1680
December1st to 15thDay
12%11%411%9%47%436%25%
1680
16th to endDay
17%12%5%8%7%3435%8%23%
1792
January1st to 15thNight
8%8%5%6%6%46%5%7%8%32%
2857
16th to endNight
10%10%48%6%445%5%7%31%
2912
February1st to 15thNight
11%12%5%8%5%3445%6%32%
2668
16th to endNight
11%8%46%6%445%46%37%
2351
March1st to 15thNight
12%8%37%424447%41%
2310
16th to endNight
14%10%47%434346%34%
2464
April1st to 15thNight
17%6%26%424445%40%
2136
16th to endNight
19%8%26%423335%38%
1885
May1st to 15thNight
16%6%24434446%42%
1861
16th to endNight
14%5%244245%6%9%39%
1752
June1st to 15thNight
8%424335%5%7%8%45%
1680
16th to endNight
7%31422435%8%54%
1538
July1st to 15thNight
321331335%9%62%
1556
16th to endNight
221231436%10%61%
1797
August1st to 15thNight
5%324414448%56%
1727
16th to endNight
8%413323245%58%
1912
September1st to 15thNight
8%313322346%60%
1979
16th to endNight
9%5%2332435%6%53%
2148
October1st to 15thNight
16%6%1442233450%
2340
16th to endNight
13%7%23313446%48%
2496
November1st to 15thNight
11%7%35%5%23345%46%
2765
16th to endNight
10%8%47%5%24446%41%
2940
December1st to 15thNight
12%11%38%7%45%5%5%6%30%
2940
16th to endNight
17%10%6%8%7%34446%27%
3136

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
51%5%14%18%10%
1740
16th to endDay
58%5%13%16%5%
2016
February1st to 15thDay
56%5%11%17%7%
1846
16th to endDay
53%5%12%18%8%1
1707
March1st to 15thDay
52%413%21%7%1
2310
16th to endDay
54%6%14%18%5%
2464
April1st to 15thDay
50%6%12%21%7%1
2472
16th to endDay
55%410%20%8%
2676
May1st to 15thDay
52%412%21%8%
2749
16th to endDay
45%5%13%20%12%1
3069
June1st to 15thDay
40%6%14%24%12%1
2940
16th to endDay
38%6%14%25%13%1
2897
July1st to 15thDay
29%6%15%28%14%3
2581
16th to endDay
28%6%16%30%15%2
2565
August1st to 15thDay
38%7%13%27%10%1
2472
16th to endDay
38%6%11%26%13%2
2642
September1st to 15thDay
34%5%14%27%17%1
2308
16th to endDay
35%5%12%31%15%
2129
October1st to 15thDay
43%410%22%18%1
1950
16th to endDay
41%313%25%14%1
2080
November1st to 15thDay
41%412%23%17%1
1751
16th to endDay
48%416%19%10%
1680
December1st to 15thDay
60%411%12%8%1
1680
16th to endDay
60%411%15%7%
1792
January1st to 15thNight
46%6%13%21%11%
2857
16th to endNight
50%5%15%19%8%
2912
February1st to 15thNight
52%5%11%20%9%
2678
16th to endNight
46%412%22%11%2
2351
March1st to 15thNight
42%5%14%25%11%1
2310
16th to endNight
51%413%22%6%1
2464
April1st to 15thNight
45%411%25%11%1
2136
16th to endNight
49%48%21%12%2
1885
May1st to 15thNight
42%6%11%24%12%1
1862
16th to endNight
40%7%13%21%14%2
1754
June1st to 15thNight
33%7%16%25%15%2
1680
16th to endNight
27%6%16%28%19%2
1538
July1st to 15thNight
20%5%16%32%19%5%
1476
16th to endNight
18%6%16%34%19%4
1690
August1st to 15thNight
26%5%15%32%17%3
1717
16th to endNight
29%312%31%17%4
1912
September1st to 15thNight
25%314%30%22%2
1979
16th to endNight
32%410%32%18%1
2148
October1st to 15thNight
38%310%26%19%2
2340
16th to endNight
37%413%24%17%1
2496
November1st to 15thNight
40%411%23%18%1
2765
16th to endNight
44%415%23%11%1
2940
December1st to 15thNight
54%5%13%19%7%
2940
16th to endNight
58%411%15%9%
3136

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
15%10%38%26%8%
180
16th to endDay
17%11%38%28%4
192
February1st to 15thDay
15%19%38%24%2
180
16th to endDay
29%13%26%23%7%
159
March1st to 15thDay
27%11%38%19%2
180
16th to endDay
27%7%26%26%10%1
192
April1st to 15thDay
25%8%33%25%6%
351
16th to endDay
29%12%26%19%9%2
568
May1st to 15thDay
24%10%26%27%7%2
618
16th to endDay
19%7%28%25%14%4
677
June1st to 15thDay
14%429%30%18%3
645
16th to endDay
13%5%32%30%13%3
611
July1st to 15thDay
6%228%33%23%6%
550
16th to endDay
8%123%36%24%5%
595
August1st to 15thDay
9%219%37%25%5%
549
16th to endDay
16%420%30%21%7%
554
September1st to 15thDay
14%323%36%18%3
343
16th to endDay
18%10%30%26%12%1
180
October1st to 15thDay
23%10%36%18%7%3
180
16th to endDay
17%13%40%19%8%
192
November1st to 15thDay
15%10%40%22%9%2
180
16th to endDay
28%12%36%19%3
180
December1st to 15thDay
15%12%41%19%10%
180
16th to endDay
26%14%39%17%2
192
January1st to 15thNight
13%11%38%27%8%
1050
16th to endNight
17%10%38%28%5%
1120
February1st to 15thNight
19%10%37%26%5%
1030
16th to endNight
15%10%38%25%7%1
881
March1st to 15thNight
17%7%35%27%10%
630
16th to endNight
20%9%34%26%9%
672
April1st to 15thNight
23%8%34%27%5%
629
16th to endNight
24%8%33%22%9%1
624
May1st to 15thNight
19%6%31%30%10%
630
16th to endNight
18%5%29%31%15%
659
June1st to 15thNight
9%428%41%14%
630
16th to endNight
9%427%43%14%
609
July1st to 15thNight
4127%38%25%2
555
16th to endNight
3219%45%27%1
612
August1st to 15thNight
6%119%41%28%2
575
16th to endNight
11%221%37%23%3
621
September1st to 15thNight
11%124%38%21%2
585
16th to endNight
12%7%34%29%15%1
585
October1st to 15thNight
19%9%34%26%10%
780
16th to endNight
20%8%32%29%9%
832
November1st to 15thNight
16%11%34%26%10%
999
16th to endNight
14%13%39%25%6%
1050
December1st to 15thNight
18%10%38%25%5%
1050
16th to endNight
22%9%37%22%7%
1120
Page generated at 2019-06-24 19:41:30. Version ac04

Copyright 2019 A. Danko


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