Peotone
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Peotone clear sky chart from 2005-11-06 to 2024-03-08.

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%
24784
18%
80733
11%
24679
44%
24679
21%
54471

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
20%
941
11%
4400
4%
926
29%
926
10%
3244
January11th to 20thNight
18%
950
10%
4399
4%
930
25%
930
8%
3503
January21st to endNight
20%
1039
8%
4767
5%
1023
26%
1023
8%
3772
February1st to 10thNight
19%
873
14%
2393
4%
873
26%
873
18%
1770
February11th to 20thNight
25%
740
20%
2219
8%
740
35%
740
20%
1511
February21st to endNight
18%
628
17%
1884
5%
628
30%
628
17%
1345
March1st to 10thNight
24%
751
15%
2251
7%
751
30%
751
18%
1571
March11th to 20thNight
29%
720
20%
2124
9%
720
39%
720
26%
1351
March21st to endNight
27%
598
16%
1984
10%
598
35%
598
17%
1398
April1st to 10thNight
26%
540
18%
1800
10%
540
38%
540
23%
1138
April11th to 20thNight
31%
533
20%
1775
14%
533
42%
533
21%
1156
April21st to endNight
31%
540
16%
1698
8%
540
40%
540
21%
1150
May1st to 10thNight
35%
540
16%
1620
9%
540
41%
540
24%
1070
May11th to 20thNight
41%
531
18%
1520
9%
531
48%
531
27%
1004
May21st to endNight
50%
583
17%
1551
10%
582
54%
582
31%
1018
June1st to 10thNight
53%
540
18%
1440
11%
540
59%
540
40%
867
June11th to 20thNight
51%
540
22%
1440
13%
540
57%
540
38%
867
June21st to endNight
51%
540
18%
1440
11%
540
56%
540
32%
930
July1st to 10thNight
67%
525
18%
1400
14%
525
69%
525
40%
828
July11th to 20thNight
65%
522
24%
1392
18%
522
69%
522
45%
799
July21st to endNight
69%
591
25%
1487
19%
558
73%
558
46%
851
August1st to 10thNight
73%
537
24%
1503
22%
534
74%
534
41%
868
August11th to 20thNight
71%
534
23%
1759
23%
534
74%
534
38%
936
August21st to endNight
66%
594
25%
1980
25%
594
71%
594
37%
1056
September1st to 10thNight
61%
540
25%
1800
25%
540
65%
540
33%
1003
September11th to 20thNight
65%
652
35%
1912
30%
652
70%
652
41%
1056
September21st to endNight
53%
720
26%
1980
18%
720
58%
720
34%
1223
October1st to 10thNight
51%
720
26%
1998
19%
720
55%
720
33%
1221
October11th to 20thNight
32%
720
24%
2178
12%
720
45%
720
26%
1361
October21st to endNight
27%
792
18%
2574
12%
792
36%
792
19%
1717
November1st to 10thNight
30%
740
26%
2406
17%
740
44%
740
28%
1402
November11th to 20thNight
26%
760
20%
2470
10%
760
39%
760
19%
1603
November21st to endNight
25%
769
20%
2479
10%
769
36%
769
19%
1656
December1st to 10thNight
21%
950
14%
2660
5%
950
29%
950
19%
1905
December11th to 20thNight
22%
950
15%
3204
5%
948
30%
948
15%
2310
December21st to endNight
14%
1041
6%
4846
3%
1026
21%
1026
6%
4011

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%9%47%6%35%5%5%7%35%
78474
Night
15%10%47%5%3445%6%37%
81137
TransparencyDay
48%311%23%13%2
78175
Night
49%310%22%14%2
80957
SeeingDay
16%10%29%25%15%6%
14755
Night
18%9%30%30%12%1
24807

By Month

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 10thDay
14%13%7%10%7%45%45%6%24%
2527
11th to 20thDay
14%15%6%13%8%446%7%417%
2530
21st to endDay
20%23%7%10%6%33335%17%
2856
February1st to 10thDay
18%11%6%8%6%45%5%47%26%
1786
11th to 20thDay
14%10%5%7%8%4445%7%32%
1848
21st to endDay
15%13%5%9%7%335%5%6%29%
1570
March1st to 10thDay
18%13%5%7%7%34445%30%
1870
11th to 20thDay
14%10%48%6%25%5%6%8%33%
1847
21st to endDay
22%12%5%7%6%45%446%25%
2376
April1st to 10thDay
17%11%5%6%6%35%45%8%32%
2160
11th to 20thDay
17%9%45%5%3445%8%36%
2134
21st to endDay
20%8%36%5%445%5%6%33%
2260
May1st to 10thDay
18%9%36%6%35%5%6%8%30%
2340
11th to 20thDay
19%7%37%6%35%46%7%34%
2371
21st to endDay
13%6%36%6%35%5%6%8%38%
2725
June1st to 10thDay
11%5%25%5%35%6%5%8%45%
2520
11th to 20thDay
10%425%6%35%5%6%9%45%
2520
21st to endDay
11%5%36%6%47%6%8%8%38%
2520
July1st to 10thDay
8%5%25%5%36%6%7%10%44%
2520
11th to 20thDay
10%4245%35%6%7%9%46%
2520
21st to endDay
7%5%25%5%36%6%7%10%44%
2743
August1st to 10thDay
7%5%25%6%36%5%7%9%45%
2423
11th to 20thDay
8%436%5%45%6%7%8%44%
2139
21st to endDay
8%425%5%346%7%8%48%
2376
September1st to 10thDay
11%6%245%35%5%6%7%45%
2160
11th to 20thDay
13%5%234345%5%8%50%
2030
21st to endDay
10%436%5%35%5%6%9%45%
1980
October1st to 10thDay
11%7%36%435%45%7%46%
1960
11th to 20thDay
19%7%25%6%345%6%7%36%
1782
21st to endDay
21%8%37%5%4345%7%33%
1782
November1st to 10thDay
13%7%244335%5%7%47%
1672
11th to 20thDay
17%9%5%6%5%2446%7%35%
1710
21st to endDay
18%10%48%5%24446%35%
1696
December1st to 10thDay
15%14%410%6%35%446%29%
1520
11th to 20thDay
14%13%49%7%45%45%6%28%
1918
21st to endDay
23%20%8%12%7%3334413%
2783
January1st to 10thNight
16%15%8%9%6%3444427%
4428
11th to 20thNight
15%17%8%12%7%35%6%6%318%
4440
21st to endNight
23%17%7%9%5%3434422%
4806
February1st to 10thNight
16%14%5%7%6%34445%31%
2393
11th to 20thNight
14%10%47%6%345%47%35%
2218
21st to endNight
18%11%48%5%3335%5%33%
1884
March1st to 10thNight
16%11%48%5%34445%34%
2251
11th to 20thNight
14%7%36%435%46%8%40%
2124
21st to endNight
19%11%47%6%34445%32%
1984
April1st to 10thNight
14%7%46%5%345%6%8%40%
1800
11th to 20thNight
18%8%36%5%35%446%39%
1775
21st to endNight
18%8%45%5%35%5%5%6%35%
1698
May1st to 10thNight
16%7%36%5%35%5%5%8%36%
1620
11th to 20thNight
16%6%25%5%35%46%8%40%
1519
21st to endNight
10%6%26%6%35%6%6%9%40%
1551
June1st to 10thNight
10%435%43446%7%50%
1440
11th to 20thNight
9%5%25%5%35%46%9%48%
1440
21st to endNight
10%6%347%45%5%7%8%43%
1440
July1st to 10thNight
7%4245%345%6%10%50%
1440
11th to 20thNight
7%225%42445%8%56%
1440
21st to endNight
4425%4345%7%9%53%
1575
August1st to 10thNight
5%3246%35%47%8%51%
1512
11th to 20thNight
7%3244346%6%9%52%
1759
21st to endNight
8%42442445%8%54%
1980
September1st to 10thNight
10%6%145%2345%7%53%
1800
11th to 20thNight
9%42432445%8%55%
1912
21st to endNight
9%5%25%5%45%5%6%8%46%
1980
October1st to 10thNight
11%5%35%434447%51%
1998
11th to 20thNight
15%8%25%423346%46%
2178
21st to endNight
21%8%36%434346%37%
2574
November1st to 10thNight
11%7%35%43345%7%48%
2406
11th to 20thNight
14%8%48%6%35%446%38%
2470
21st to endNight
18%9%45%5%34346%37%
2479
December1st to 10thNight
17%11%48%5%44446%33%
2660
11th to 20thNight
16%14%49%6%34345%32%
3279
21st to endNight
24%17%7%10%7%3444416%
4884

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
63%212%17%6%
2528
11th to 20thDay
68%29%12%9%1
2530
21st to endDay
73%17%13%5%
2856
February1st to 10thDay
59%211%17%9%2
1786
11th to 20thDay
53%29%24%10%2
1858
21st to endDay
58%29%21%6%2
1570
March1st to 10thDay
57%210%23%7%1
1870
11th to 20thDay
50%312%23%11%1
1847
21st to endDay
61%410%19%5%1
2376
April1st to 10thDay
52%310%20%14%
2160
11th to 20thDay
49%310%22%12%4
2134
21st to endDay
53%312%18%12%2
2260
May1st to 10thDay
52%411%25%8%
2340
11th to 20thDay
50%312%22%12%1
2375
21st to endDay
44%410%22%17%2
2725
June1st to 10thDay
36%411%27%19%2
2520
11th to 20thDay
36%311%26%21%4
2520
21st to endDay
40%6%15%23%14%2
2520
July1st to 10thDay
35%5%12%29%16%3
2451
11th to 20thDay
35%5%14%29%15%2
2445
21st to endDay
34%5%16%26%16%3
2591
August1st to 10thDay
34%416%31%13%2
2408
11th to 20thDay
36%415%27%18%1
2139
21st to endDay
32%412%27%20%4
2376
September1st to 10thDay
37%412%27%16%4
2160
11th to 20thDay
34%310%29%20%4
2030
21st to endDay
36%49%28%21%2
1980
October1st to 10thDay
39%412%27%16%3
1960
11th to 20thDay
48%210%23%15%1
1782
21st to endDay
52%310%23%10%2
1782
November1st to 10thDay
37%215%26%17%2
1672
11th to 20thDay
50%212%24%12%1
1710
21st to endDay
53%310%23%11%1
1696
December1st to 10thDay
59%211%19%8%1
1520
11th to 20thDay
59%210%21%7%1
1915
21st to endDay
77%27%10%4
2783
January1st to 10thNight
63%29%17%8%1
4428
11th to 20thNight
70%110%12%6%
4440
21st to endNight
69%18%15%6%
4806
February1st to 10thNight
57%210%19%10%2
2393
11th to 20thNight
50%29%23%14%2
2219
21st to endNight
55%38%20%11%3
1884
March1st to 10thNight
53%210%24%9%1
2251
11th to 20thNight
43%313%22%16%3
2124
21st to endNight
54%411%21%10%1
1984
April1st to 10thNight
44%312%25%14%2
1800
11th to 20thNight
48%27%22%17%4
1775
21st to endNight
49%410%20%14%3
1698
May1st to 10thNight
46%313%25%12%
1620
11th to 20thNight
43%5%13%23%16%1
1520
21st to endNight
40%5%13%21%16%4
1552
June1st to 10thNight
34%212%27%21%4
1440
11th to 20thNight
33%312%25%23%3
1440
21st to endNight
39%415%23%15%4
1440
July1st to 10thNight
31%416%28%16%5%
1400
11th to 20thNight
28%313%29%24%3
1392
21st to endNight
27%416%29%20%5%
1487
August1st to 10thNight
30%416%31%18%1
1503
11th to 20thNight
29%416%28%21%3
1759
21st to endNight
29%411%30%21%5%
1980
September1st to 10thNight
33%411%25%22%5%
1800
11th to 20thNight
29%38%30%26%4
1912
21st to endNight
36%49%29%19%3
1980
October1st to 10thNight
35%49%27%22%3
1998
11th to 20thNight
42%27%27%21%2
2178
21st to endNight
50%29%23%15%2
2574
November1st to 10thNight
38%39%29%19%4
2406
11th to 20thNight
48%211%23%15%2
2470
21st to endNight
51%210%25%12%
2479
December1st to 10thNight
54%212%22%10%1
2660
11th to 20thNight
57%110%19%12%1
3281
21st to endNight
74%28%11%5%
4884

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
21%12%34%26%6%1
270
11th to 20thDay
26%17%34%16%5%1
270
21st to endDay
23%14%35%22%6%
297
February1st to 10thDay
25%17%37%16%4
270
11th to 20thDay
24%13%37%21%4
270
21st to endDay
24%19%40%13%4
225
March1st to 10thDay
21%21%35%21%2
261
11th to 20thDay
22%15%34%22%7%
276
21st to endDay
32%13%29%19%6%2
462
April1st to 10thDay
21%13%32%24%9%1
420
11th to 20thDay
21%15%32%19%11%3
412
21st to endDay
21%17%32%20%7%2
420
May1st to 10thDay
22%13%31%22%9%3
423
11th to 20thDay
21%7%32%21%14%4
517
21st to endDay
14%8%30%23%16%8%
679
June1st to 10thDay
9%7%30%30%19%6%
630
11th to 20thDay
12%5%29%31%19%5%
630
21st to endDay
13%8%28%31%14%5%
630
July1st to 10thDay
8%5%19%29%24%16%
621
11th to 20thDay
10%5%22%31%20%11%
618
21st to endDay
8%323%35%23%8%
684
August1st to 10thDay
9%215%32%29%14%
542
11th to 20thDay
10%416%28%26%16%
439
21st to endDay
8%218%36%23%13%
495
September1st to 10thDay
12%6%20%30%24%9%
450
11th to 20thDay
12%5%15%26%29%12%
450
21st to endDay
11%7%26%27%20%9%
450
October1st to 10thDay
14%6%29%28%18%5%
430
11th to 20thDay
21%20%32%21%7%
270
21st to endDay
32%11%35%18%4
297
November1st to 10thDay
15%13%36%23%9%5%
270
11th to 20thDay
23%14%36%16%9%1
270
21st to endDay
24%11%37%22%6%
270
December1st to 10thDay
17%17%39%18%8%1
270
11th to 20thDay
20%15%37%22%6%
270
21st to endDay
24%21%39%13%2
297
January1st to 10thNight
20%15%38%23%4
950
11th to 20thNight
24%14%36%22%4
950
21st to endNight
22%12%34%27%4
1045
February1st to 10thNight
25%12%37%23%3
873
11th to 20thNight
20%13%36%27%4
743
21st to endNight
24%15%38%20%3
628
March1st to 10thNight
23%13%35%24%5%
751
11th to 20thNight
18%10%38%26%6%1
720
21st to endNight
25%9%34%23%7%1
598
April1st to 10thNight
18%10%40%26%6%1
540
11th to 20thNight
21%12%32%26%8%
533
21st to endNight
21%10%32%28%9%1
540
May1st to 10thNight
19%6%35%31%9%
540
11th to 20thNight
17%5%30%34%13%1
531
21st to endNight
11%427%37%19%1
584
June1st to 10thNight
11%326%45%15%
540
11th to 20thNight
11%426%42%15%2
540
21st to endNight
11%427%39%19%1
540
July1st to 10thNight
8%215%43%28%4
525
11th to 20thNight
7%318%41%29%3
522
21st to endNight
5%218%47%27%1
591
August1st to 10thNight
5%210%49%31%4
537
11th to 20thNight
8%212%41%32%5%
534
21st to endNight
8%217%36%32%4
594
September1st to 10thNight
11%316%39%27%4
540
11th to 20thNight
10%417%37%28%4
652
21st to endNight
11%6%24%33%23%3
720
October1st to 10thNight
14%6%25%35%20%1
720
11th to 20thNight
20%13%31%27%9%
720
21st to endNight
25%13%31%24%7%
792
November1st to 10thNight
15%11%39%25%10%1
740
11th to 20thNight
19%16%33%26%6%
760
21st to endNight
22%12%35%24%7%
769
December1st to 10thNight
23%13%35%24%5%
950
11th to 20thNight
24%11%34%26%5%
950
21st to endNight
29%13%33%23%2
1045
Page generated at 2024-03-05 06:24:01. Version ac07

Copyright © 2024 Attilla Danko.


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