IU Kokomo Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the IU Kokomo Observatory clear sky chart from 2005-11-05 to 2018-10-27.

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
39%
17340
18%
51197
12%
17298
45%
17298
23%
34305

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
17%
975
14%
2716
5%
970
25%
970
15%
2083
January16th to endNight
20%
1009
12%
2881
4%
1009
26%
1009
15%
2195
February1st to 15thNight
21%
761
11%
2306
4%
761
27%
761
15%
1693
February16th to endNight
22%
683
15%
2049
6%
683
29%
683
16%
1493
March1st to 15thNight
27%
780
15%
2325
9%
780
31%
780
17%
1637
March16th to endNight
29%
774
17%
2230
8%
774
37%
774
20%
1575
April1st to 15thNight
29%
584
16%
1947
9%
584
39%
584
20%
1306
April16th to endNight
34%
579
20%
1806
11%
579
44%
579
25%
1158
May1st to 15thNight
38%
585
14%
1755
9%
585
43%
585
22%
1207
May16th to endNight
53%
610
16%
1757
11%
609
57%
609
28%
1145
June1st to 15thNight
58%
585
18%
1560
13%
585
63%
585
37%
950
June16th to endNight
58%
585
18%
1560
12%
585
62%
585
35%
977
July1st to 15thNight
64%
555
18%
1480
15%
555
66%
555
38%
898
July16th to endNight
71%
612
22%
1575
17%
579
74%
579
44%
898
August1st to 15thNight
70%
575
23%
1715
21%
572
72%
572
39%
968
August16th to endNight
66%
621
20%
2056
20%
621
70%
621
35%
1127
September1st to 15thNight
62%
656
27%
2021
24%
656
66%
656
34%
1177
September16th to endNight
63%
777
28%
2145
21%
777
67%
777
37%
1271
October1st to 15thNight
50%
780
26%
2145
20%
780
55%
780
33%
1332
October16th to endNight
31%
816
19%
2637
14%
816
40%
816
22%
1674
November1st to 15thNight
37%
760
24%
2471
17%
760
48%
760
26%
1499
November16th to endNight
27%
780
19%
2535
12%
780
36%
780
18%
1725
December1st to 15thNight
21%
858
11%
2613
5%
858
28%
858
15%
1967
December16th to endNight
16%
1040
10%
2912
3%
1040
23%
1040
11%
2350

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
14%8%36%5%35%45%7%35%
52356
Night
14%8%36%5%34446%38%
51369
Cloud CoverDay
14%8%36%5%35%45%7%35%
52365
Night
14%8%36%5%34446%38%
51374
TransparencyDay
47%412%21%12%1
52046
Night
45%411%22%14%2
51197
SeeingDay
17%6%24%24%19%7%
7360
Night
18%8%27%29%14%1
17344

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
18%16%5%7%6%35%45%422%
1552
16th to endDay
14%17%6%8%6%34346%23%
1693
February1st to 15thDay
15%14%6%8%7%35%435%24%
1884
16th to endDay
16%13%6%8%5%34445%26%
1710
March1st to 15thDay
18%12%5%8%6%23346%27%
1954
16th to endDay
19%10%46%5%1445%7%30%
2356
April1st to 15thDay
19%9%35%5%24446%33%
2331
16th to endDay
17%8%36%5%3335%6%36%
2427
May1st to 15thDay
18%9%36%5%45%45%7%29%
2526
16th to endDay
12%5%35%5%45%5%6%8%36%
2707
June1st to 15thDay
10%5%25%6%45%5%5%7%43%
2730
16th to endDay
9%435%5%36%6%6%9%40%
2730
July1st to 15thDay
8%6%25%435%5%6%9%42%
2730
16th to endDay
8%3245%45%6%8%10%40%
2844
August1st to 15thDay
6%425%435%6%6%9%45%
2487
16th to endDay
8%425%5%36%5%6%9%42%
2496
September1st to 15thDay
12%4244345%5%7%43%
2256
16th to endDay
10%5%24425%45%6%47%
2145
October1st to 15thDay
15%6%25%43445%5%40%
2145
16th to endDay
17%7%25%5%3445%6%36%
1843
November1st to 15thDay
14%7%35%324345%44%
1717
16th to endDay
18%10%46%5%25%35%6%31%
1755
December1st to 15thDay
18%12%6%9%6%34336%24%
1674
16th to endDay
22%15%6%8%6%25%245%19%
1664
January1st to 15thNight
18%13%5%9%6%3333427%
2716
16th to endNight
14%14%6%9%6%34435%27%
2881
February1st to 15thNight
17%12%5%7%5%3334430%
2304
16th to endNight
17%12%5%7%6%34345%30%
2049
March1st to 15thNight
16%10%5%6%5%2445%5%32%
2312
16th to endNight
16%10%37%5%33446%33%
2230
April1st to 15thNight
16%8%35%6%25%446%36%
1947
16th to endNight
16%7%25%423447%40%
1806
May1st to 15thNight
18%6%35%5%35%447%35%
1755
16th to endNight
11%5%25%425%5%6%8%40%
1755
June1st to 15thNight
7%426%43345%8%49%
1560
16th to endNight
8%5%24425%5%5%9%45%
1560
July1st to 15thNight
7%4235%345%6%10%46%
1560
16th to endNight
5%32442346%8%53%
1673
August1st to 15thNight
5%325%4345%8%9%49%
1726
16th to endNight
6%315%5%2346%7%51%
2056
September1st to 15thNight
11%424423346%51%
2021
16th to endNight
9%41442345%7%51%
2145
October1st to 15thNight
12%5%2442436%7%46%
2145
16th to endNight
17%6%36%423346%42%
2637
November1st to 15thNight
13%7%3442345%6%44%
2471
16th to endNight
18%9%46%5%33346%33%
2535
December1st to 15thNight
19%11%6%8%6%24245%28%
2613
16th to endNight
22%14%5%8%6%34435%20%
2912

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
18%15%5%8%5%35%44422%
1552
16th to endDay
14%17%6%8%6%34446%23%
1693
February1st to 15thDay
15%14%6%8%7%35%43425%
1884
16th to endDay
16%13%6%8%6%24445%26%
1710
March1st to 15thDay
19%12%5%8%5%24346%27%
1964
16th to endDay
19%10%46%5%2445%7%30%
2355
April1st to 15thDay
20%9%36%424446%33%
2331
16th to endDay
17%8%37%5%3335%6%36%
2427
May1st to 15thDay
18%8%45%6%445%47%30%
2526
16th to endDay
13%6%25%6%45%45%8%37%
2707
June1st to 15thDay
10%5%25%6%4446%6%43%
2730
16th to endDay
10%425%5%36%5%6%9%40%
2730
July1st to 15thDay
8%6%25%426%5%6%9%42%
2730
16th to endDay
8%3146%36%6%7%10%40%
2844
August1st to 15thDay
6%425%435%6%6%9%45%
2487
16th to endDay
9%425%6%35%5%6%9%42%
2496
September1st to 15thDay
12%4245%35%45%6%43%
2256
16th to endDay
11%5%24425%447%47%
2145
October1st to 15thDay
15%7%35%434446%41%
2145
16th to endDay
18%7%25%5%3445%6%37%
1843
November1st to 15thDay
15%7%25%333246%45%
1717
16th to endDay
18%10%36%5%3435%5%32%
1755
December1st to 15thDay
18%12%5%10%6%34335%25%
1674
16th to endDay
23%16%5%8%5%35%335%19%
1664
January1st to 15thNight
18%13%5%9%6%3333428%
2716
16th to endNight
14%13%6%9%6%3433427%
2881
February1st to 15thNight
17%13%5%7%5%33335%30%
2297
16th to endNight
17%12%47%6%24445%30%
2049
March1st to 15thNight
17%9%5%6%42445%5%33%
2325
16th to endNight
16%10%27%5%3345%6%33%
2230
April1st to 15thNight
16%8%35%5%35%446%36%
1947
16th to endNight
16%7%35%413447%40%
1806
May1st to 15thNight
18%6%35%5%3445%6%35%
1754
16th to endNight
12%425%5%25%6%6%7%40%
1755
June1st to 15thNight
8%426%43345%7%50%
1560
16th to endNight
8%5%24425%5%49%46%
1560
July1st to 15thNight
7%4235%336%6%10%47%
1560
16th to endNight
5%3245%2446%8%53%
1673
August1st to 15thNight
5%3244345%8%9%49%
1726
16th to endNight
7%315%5%2345%8%51%
2056
September1st to 15thNight
11%424423446%51%
2021
16th to endNight
9%424333447%51%
2145
October1st to 15thNight
13%5%2443336%7%46%
2145
16th to endNight
17%6%26%423336%41%
2637
November1st to 15thNight
13%7%34423446%44%
2471
16th to endNight
18%10%46%5%23347%33%
2535
December1st to 15thNight
19%12%6%8%6%23245%28%
2613
16th to endNight
22%14%5%9%5%34435%20%
2912

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
63%39%15%7%
1553
16th to endDay
61%314%14%6%
1693
February1st to 15thDay
62%310%15%7%
1886
16th to endDay
59%412%18%5%
1710
March1st to 15thDay
58%312%17%7%
1964
16th to endDay
52%415%20%5%1
2356
April1st to 15thDay
50%411%21%11%
2331
16th to endDay
48%410%19%10%5%
2427
May1st to 15thDay
53%5%13%18%8%
2526
16th to endDay
43%5%11%21%14%2
2711
June1st to 15thDay
39%411%25%17%1
2730
16th to endDay
38%7%13%22%15%2
2730
July1st to 15thDay
37%5%10%24%17%3
2581
16th to endDay
35%6%17%24%13%2
2679
August1st to 15thDay
32%7%14%26%17%1
2474
16th to endDay
37%5%12%23%16%5%
2496
September1st to 15thDay
39%412%21%18%3
2256
16th to endDay
35%49%26%21%1
2145
October1st to 15thDay
43%411%23%15%1
2145
16th to endDay
46%411%23%12%
1843
November1st to 15thDay
41%310%23%17%2
1717
16th to endDay
53%312%22%7%1
1755
December1st to 15thDay
62%210%19%5%
1674
16th to endDay
68%310%13%3
1664
January1st to 15thNight
60%26%18%10%
2716
16th to endNight
60%212%17%6%
2881
February1st to 15thNight
57%313%16%8%1
2306
16th to endNight
56%310%20%8%
2049
March1st to 15thNight
52%310%21%9%2
2325
16th to endNight
50%5%11%22%8%1
2230
April1st to 15thNight
48%410%22%12%1
1947
16th to endNight
43%49%22%14%6%
1806
May1st to 15thNight
47%5%13%21%10%1
1755
16th to endNight
39%7%12%21%15%4
1757
June1st to 15thNight
32%5%11%26%21%2
1560
16th to endNight
34%5%15%24%16%3
1560
July1st to 15thNight
31%5%14%23%19%5%
1480
16th to endNight
27%417%28%18%4
1575
August1st to 15thNight
27%6%14%24%24%1
1715
16th to endNight
29%5%13%24%21%4
2056
September1st to 15thNight
33%410%24%21%5%
2021
16th to endNight
32%49%25%25%2
2145
October1st to 15thNight
36%310%26%20%2
2145
16th to endNight
43%39%27%14%1
2637
November1st to 15thNight
39%48%24%19%4
2471
16th to endNight
51%211%24%9%
2535
December1st to 15thNight
59%39%18%8%
2613
16th to endNight
66%39%14%5%
2912

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
27%12%39%13%6%
135
16th to endDay
27%13%40%18%1
144
February1st to 15thDay
22%17%40%16%2
135
16th to endDay
31%13%30%17%6%
120
March1st to 15thDay
27%14%35%20%2
149
16th to endDay
29%7%32%19%10%1
352
April1st to 15thDay
26%11%30%20%10%1
330
16th to endDay
21%9%28%19%15%5%
319
May1st to 15thDay
20%10%27%25%10%4
348
16th to endDay
18%425%24%17%9%
463
June1st to 15thDay
10%425%31%22%5%
570
16th to endDay
13%426%29%18%7%
570
July1st to 15thDay
11%219%27%24%15%
550
16th to endDay
10%212%31%28%15%
560
August1st to 15thDay
10%18%28%31%19%
358
16th to endDay
11%215%24%33%12%
396
September1st to 15thDay
15%111%27%30%12%
375
16th to endDay
13%413%21%36%10%
374
October1st to 15thDay
18%6%22%28%18%5%
375
16th to endDay
23%11%35%25%4
188
November1st to 15thDay
17%11%22%18%22%5%
135
16th to endDay
23%13%41%14%6%
135
December1st to 15thDay
17%21%38%14%8%
135
16th to endDay
29%20%38%9%2
144
January1st to 15thNight
25%13%36%20%4
975
16th to endNight
20%14%35%26%3
1009
February1st to 15thNight
26%11%33%25%3
764
16th to endNight
24%11%34%25%4
683
March1st to 15thNight
21%12%33%27%6%
780
16th to endNight
21%8%34%26%8%
774
April1st to 15thNight
20%10%36%25%7%
584
16th to endNight
20%6%33%26%11%1
579
May1st to 15thNight
20%5%27%33%11%
585
16th to endNight
13%421%38%19%3
611
June1st to 15thNight
9%222%46%18%
585
16th to endNight
11%220%41%24%1
585
July1st to 15thNight
8%114%41%28%4
555
16th to endNight
7%111%37%37%4
612
August1st to 15thNight
6%12%41%32%6%
575
16th to endNight
7%113%36%35%5%
621
September1st to 15thNight
14%215%33%30%4
656
16th to endNight
11%414%34%31%3
777
October1st to 15thNight
15%7%21%34%18%3
780
16th to endNight
21%10%31%25%9%
816
November1st to 15thNight
18%8%31%27%12%1
760
16th to endNight
24%12%29%23%8%
780
December1st to 15thNight
26%11%32%22%6%
858
16th to endNight
28%13%32%21%4
1040
Page generated at 2018-10-28 08:41:06. Version ac04

Copyright 2018 A. Danko


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