Carbondale
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Carbondale clear sky chart from 2005-11-06 to 2024-01-31.

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
41%
24377
22%
74830
14%
24318
48%
24318
26%
47292

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
22%
950
19%
2648
7%
946
32%
946
21%
1796
January11th to 20thNight
18%
950
18%
2580
6%
950
26%
950
18%
1873
January21st to endNight
19%
1043
19%
2711
5%
1043
29%
1043
22%
1922
February1st to 10thNight
18%
806
16%
2246
6%
806
27%
806
18%
1646
February11th to 20thNight
19%
703
20%
2099
7%
700
30%
700
19%
1406
February21st to endNight
19%
592
18%
1776
6%
592
29%
592
18%
1227
March1st to 10thNight
22%
720
19%
2160
7%
720
33%
720
22%
1429
March11th to 20thNight
25%
616
17%
2056
9%
616
35%
616
18%
1375
March21st to endNight
28%
594
15%
2008
9%
594
36%
594
17%
1391
April1st to 10thNight
32%
540
24%
1800
14%
540
46%
540
27%
1038
April11th to 20thNight
39%
533
23%
1775
17%
533
50%
533
26%
1084
April21st to endNight
32%
540
19%
1800
11%
540
43%
540
22%
1175
May1st to 10thNight
41%
540
18%
1697
12%
540
47%
540
26%
1082
May11th to 20thNight
43%
531
18%
1585
13%
531
48%
531
25%
1046
May21st to endNight
55%
584
21%
1551
13%
582
59%
582
32%
1005
June1st to 10thNight
62%
540
21%
1440
16%
540
65%
540
36%
899
June11th to 20thNight
68%
540
28%
1440
22%
540
72%
540
45%
812
June21st to endNight
70%
540
25%
1440
18%
540
72%
540
44%
807
July1st to 10thNight
73%
525
19%
1400
17%
525
74%
525
38%
852
July11th to 20thNight
75%
522
23%
1392
20%
522
76%
522
42%
810
July21st to endNight
68%
591
26%
1553
23%
558
71%
558
40%
897
August1st to 10thNight
76%
537
21%
1716
24%
534
77%
534
37%
931
August11th to 20thNight
70%
534
25%
1776
29%
534
72%
534
34%
997
August21st to endNight
74%
594
26%
1980
31%
594
76%
594
37%
1071
September1st to 10thNight
63%
540
27%
1800
27%
540
67%
540
31%
1022
September11th to 20thNight
66%
602
33%
1862
30%
602
70%
602
37%
1050
September21st to endNight
58%
720
30%
1980
20%
720
64%
720
39%
1155
October1st to 10thNight
59%
720
30%
2056
23%
720
63%
720
41%
1133
October11th to 20thNight
40%
720
31%
2160
18%
720
53%
720
33%
1262
October21st to endNight
32%
792
25%
2445
15%
792
44%
792
26%
1540
November1st to 10thNight
40%
740
30%
2406
21%
740
53%
740
36%
1302
November11th to 20thNight
35%
760
29%
2470
17%
760
50%
760
30%
1407
November21st to endNight
32%
760
24%
2470
16%
760
42%
760
25%
1534
December1st to 10thNight
28%
870
18%
2580
9%
870
38%
870
22%
1727
December11th to 20thNight
29%
948
21%
3156
10%
948
37%
948
20%
2071
December21st to endNight
18%
1040
11%
4816
5%
1026
30%
1026
11%
3518

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
12%7%35%5%35%5%5%8%42%
74936
Night
13%7%35%5%3445%7%45%
75208
TransparencyDay
40%7%11%24%16%3
74642
Night
40%5%10%24%18%3
75024
SeeingDay
15%11%25%26%17%7%
14420
Night
16%10%28%29%15%2
24384

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%11%48%6%44445%36%
1517
11th to 20thDay
17%10%48%5%2445%7%34%
1596
21st to endDay
12%12%5%8%6%43446%37%
1872
February1st to 10thDay
15%12%5%6%424446%37%
1712
11th to 20thDay
15%9%47%6%4445%7%36%
1748
21st to endDay
15%11%46%5%3445%6%36%
1480
March1st to 10thDay
15%8%36%5%36%45%6%41%
1800
11th to 20thDay
18%10%47%6%3445%5%35%
1919
21st to endDay
18%9%48%5%35%5%5%6%32%
2346
April1st to 10thDay
10%6%36%4345%5%8%46%
2160
11th to 20thDay
15%7%36%6%35%446%41%
2134
21st to endDay
18%6%25%6%345%5%7%39%
2160
May1st to 10thDay
16%5%36%5%346%6%9%37%
2262
11th to 20thDay
15%6%35%5%35%5%5%8%40%
2305
21st to endDay
9%5%36%6%5%6%7%7%9%36%
2725
June1st to 10thDay
8%4245%35%6%6%9%47%
2520
11th to 20thDay
5%3245%35%6%6%10%51%
2520
21st to endDay
5%3245%36%6%6%11%47%
2520
July1st to 10thDay
10%3146%46%7%7%11%41%
2520
11th to 20thDay
5%3135%36%6%8%11%49%
2520
21st to endDay
7%4245%36%6%8%9%44%
2670
August1st to 10thDay
7%425%5%36%6%8%11%43%
2212
11th to 20thDay
8%5%246%36%6%7%10%42%
2125
21st to endDay
7%5%245%35%6%7%8%48%
2376
September1st to 10thDay
12%6%25%43445%7%47%
2160
11th to 20thDay
8%5%25%5%345%5%8%48%
2080
21st to endDay
10%324433448%56%
1980
October1st to 10thDay
10%414324446%58%
1900
11th to 20thDay
12%5%25%42435%6%51%
1800
21st to endDay
19%7%25%323345%45%
1908
November1st to 10thDay
10%5%245%34446%54%
1672
11th to 20thDay
13%7%35%5%3445%6%47%
1710
21st to endDay
16%10%35%43445%6%42%
1710
December1st to 10thDay
15%10%26%5%34446%40%
1596
11th to 20thDay
13%11%47%6%45%45%6%36%
1918
21st to endDay
19%16%5%7%6%33446%29%
2783
January1st to 10thNight
15%9%46%6%34446%39%
2648
11th to 20thNight
16%11%48%5%34445%35%
2580
21st to endNight
15%9%46%6%3445%6%36%
2711
February1st to 10thNight
18%12%6%8%5%34335%34%
2246
11th to 20thNight
16%6%47%5%3435%5%41%
2098
21st to endNight
19%9%5%5%5%25%35%438%
1776
March1st to 10thNight
15%9%35%6%34445%43%
2160
11th to 20thNight
19%8%36%5%44445%39%
2056
21st to endNight
18%9%37%5%35%5%5%6%34%
2008
April1st to 10thNight
12%5%346%3446%7%48%
1800
11th to 20thNight
16%5%25%43445%8%44%
1775
21st to endNight
19%6%26%5%245%46%40%
1800
May1st to 10thNight
15%6%35%5%2446%7%44%
1697
11th to 20thNight
13%6%26%5%36%5%5%6%43%
1584
21st to endNight
7%436%7%46%5%7%10%42%
1551
June1st to 10thNight
10%425%435%46%8%48%
1440
11th to 20thNight
5%3234345%5%10%55%
1440
21st to endNight
42234346%8%12%52%
1440
July1st to 10thNight
6%3245%446%7%9%50%
1440
11th to 20thNight
44245%35%6%7%9%52%
1440
21st to endNight
6%424435%6%6%10%50%
1644
August1st to 10thNight
6%314335%5%6%12%52%
1726
11th to 20thNight
7%5%25%5%34449%52%
1776
21st to endNight
6%4244345%6%8%54%
1980
September1st to 10thNight
11%6%25%5%33345%53%
1800
11th to 20thNight
8%425%5%3445%8%52%
1862
21st to endNight
11%42343345%8%55%
1980
October1st to 10thNight
7%42443335%6%59%
2056
11th to 20thNight
13%5%25%423335%54%
2160
21st to endNight
19%7%25%323345%47%
2445
November1st to 10thNight
11%424323446%57%
2406
11th to 20thNight
13%5%25%423447%51%
2470
21st to endNight
17%7%35%423335%47%
2470
December1st to 10thNight
16%9%45%42446%7%39%
2580
11th to 20thNight
14%9%45%5%35%445%42%
3279
21st to endNight
16%15%48%6%45%445%29%
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
52%38%23%11%3
1518
11th to 20thDay
50%5%10%24%10%1
1596
21st to endDay
50%5%11%23%10%2
1872
February1st to 10thDay
50%411%22%11%1
1712
11th to 20thDay
49%49%20%13%4
1758
21st to endDay
49%5%9%21%12%4
1480
March1st to 10thDay
45%5%8%24%16%3
1800
11th to 20thDay
52%5%10%18%12%2
1919
21st to endDay
53%5%12%19%9%1
2346
April1st to 10thDay
35%6%12%28%18%1
2160
11th to 20thDay
45%5%10%22%15%3
2134
21st to endDay
44%7%11%24%12%2
2160
May1st to 10thDay
44%8%13%25%10%1
2262
11th to 20thDay
41%8%13%22%14%1
2309
21st to endDay
42%9%14%20%12%2
2725
June1st to 10thDay
32%8%13%27%19%2
2520
11th to 20thDay
28%8%12%28%21%3
2520
21st to endDay
30%8%17%23%17%5%
2520
July1st to 10thDay
34%10%15%23%14%4
2451
11th to 20thDay
27%9%16%27%18%3
2445
21st to endDay
32%10%12%31%13%2
2522
August1st to 10thDay
32%10%12%29%16%1
2198
11th to 20thDay
34%9%13%28%14%2
2125
21st to endDay
31%7%15%25%17%5%
2376
September1st to 10thDay
36%5%10%27%18%4
2160
11th to 20thDay
32%7%9%24%25%2
2080
21st to endDay
29%5%9%27%27%4
1980
October1st to 10thDay
26%5%10%28%26%4
1900
11th to 20thDay
34%5%8%26%21%7%
1800
21st to endDay
42%5%6%26%18%4
1908
November1st to 10thDay
32%5%10%27%19%6%
1672
11th to 20thDay
39%48%22%22%5%
1710
21st to endDay
44%5%8%24%17%2
1710
December1st to 10thDay
45%5%11%25%12%1
1596
11th to 20thDay
50%5%8%23%13%1
1915
21st to endDay
58%5%11%15%10%1
2783
January1st to 10thNight
46%410%23%15%2
2648
11th to 20thNight
52%49%22%12%1
2580
21st to endNight
47%5%11%22%13%2
2711
February1st to 10thNight
55%38%21%11%2
2246
11th to 20thNight
46%48%22%16%3
2099
21st to endNight
50%49%20%13%3
1776
March1st to 10thNight
45%48%19%19%5%
2160
11th to 20thNight
48%5%11%20%13%3
2056
21st to endNight
51%5%12%21%10%2
2008
April1st to 10thNight
35%5%12%27%18%3
1800
11th to 20thNight
39%410%23%19%4
1775
21st to endNight
44%6%9%24%14%3
1800
May1st to 10thNight
39%7%11%26%15%2
1697
11th to 20thNight
41%8%12%22%16%2
1585
21st to endNight
36%8%15%23%16%3
1552
June1st to 10thNight
33%7%12%24%21%3
1440
11th to 20thNight
23%7%12%28%24%6%
1440
21st to endNight
22%9%16%27%18%8%
1440
July1st to 10thNight
28%9%16%25%16%5%
1400
11th to 20thNight
25%8%14%28%18%6%
1392
21st to endNight
27%8%15%31%19%1
1553
August1st to 10thNight
24%9%18%29%18%1
1716
11th to 20thNight
30%7%13%25%23%2
1776
21st to endNight
27%7%14%27%20%5%
1980
September1st to 10thNight
34%47%30%19%6%
1800
11th to 20thNight
30%5%9%28%24%4
1862
21st to endNight
29%6%9%23%27%7%
1980
October1st to 10thNight
26%5%9%24%30%5%
2056
11th to 20thNight
34%46%24%26%7%
2160
21st to endNight
41%47%24%18%6%
2445
November1st to 10thNight
29%5%10%27%24%6%
2406
11th to 20thNight
34%48%24%23%6%
2470
21st to endNight
42%37%25%21%2
2470
December1st to 10thNight
45%6%12%23%13%2
2580
11th to 20thNight
45%5%8%24%17%2
3281
21st to endNight
58%5%9%16%10%2
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
24%20%30%22%31
270
11th to 20thDay
26%24%36%11%3
270
21st to endDay
20%27%35%14%3
294
February1st to 10thDay
25%23%38%10%2
240
11th to 20thDay
29%27%33%9%2
240
21st to endDay
29%26%30%12%31
198
March1st to 10thDay
20%24%38%15%3
240
11th to 20thDay
29%21%33%15%2
240
21st to endDay
26%20%31%17%6%
432
April1st to 10thDay
15%21%33%23%7%1
420
11th to 20thDay
21%20%25%26%7%1
412
21st to endDay
21%15%33%22%7%1
420
May1st to 10thDay
20%17%29%23%9%2
423
11th to 20thDay
19%10%28%23%17%3
451
21st to endDay
10%5%29%31%17%8%
679
June1st to 10thDay
10%420%27%26%12%
630
11th to 20thDay
5%322%39%22%8%
630
21st to endDay
6%5%27%33%21%9%
630
July1st to 10thDay
9%314%29%26%20%
621
11th to 20thDay
7%217%32%30%12%
618
21st to endDay
7%316%34%29%12%
684
August1st to 10thDay
8%212%33%33%12%
510
11th to 20thDay
12%315%27%32%10%
439
21st to endDay
11%211%27%33%17%
495
September1st to 10thDay
12%214%30%32%11%
450
11th to 20thDay
7%214%29%34%14%
450
21st to endDay
12%8%20%28%22%10%
450
October1st to 10thDay
9%6%26%38%14%7%
370
11th to 20thDay
17%14%37%23%8%1
270
21st to endDay
27%16%30%22%5%
297
November1st to 10thDay
13%12%34%26%11%4
270
11th to 20thDay
15%23%28%25%9%1
270
21st to endDay
26%18%27%21%7%1
270
December1st to 10thDay
15%22%38%13%9%3
270
11th to 20thDay
25%20%30%19%6%
270
21st to endDay
24%25%36%13%3
297
January1st to 10thNight
21%20%33%23%4
950
11th to 20thNight
22%22%35%17%4
950
21st to endNight
21%16%39%23%1
1043
February1st to 10thNight
25%17%36%20%2
806
11th to 20thNight
23%20%34%23%1
703
21st to endNight
25%17%35%21%1
592
March1st to 10thNight
21%17%38%22%3
720
11th to 20thNight
22%13%36%23%5%
616
21st to endNight
24%12%30%25%8%
594
April1st to 10thNight
15%14%36%28%7%
540
11th to 20thNight
17%13%28%30%11%1
533
21st to endNight
22%9%33%27%8%1
540
May1st to 10thNight
17%6%31%35%10%1
540
11th to 20thNight
16%6%27%31%17%2
531
21st to endNight
9%421%39%24%3
584
June1st to 10thNight
11%318%36%29%2
540
11th to 20thNight
5%218%50%24%2
540
21st to endNight
4217%45%30%2
540
July1st to 10thNight
7%211%34%37%9%
525
11th to 20thNight
4210%42%35%6%
522
21st to endNight
9%212%37%36%5%
591
August1st to 10thNight
7%110%37%38%6%
537
11th to 20thNight
9%111%37%37%5%
534
21st to endNight
6%210%35%41%7%
594
September1st to 10thNight
12%213%30%37%6%
540
11th to 20thNight
10%214%32%36%6%
602
21st to endNight
12%5%20%32%27%5%
720
October1st to 10thNight
8%6%21%38%22%5%
720
11th to 20thNight
17%8%30%29%15%2
720
21st to endNight
24%9%32%26%8%1
792
November1st to 10thNight
12%9%35%31%12%1
740
11th to 20thNight
15%13%33%29%11%
760
21st to endNight
23%11%31%26%9%
760
December1st to 10thNight
21%13%34%28%4
870
11th to 20thNight
21%12%35%27%6%
950
21st to endNight
23%17%36%20%3
1045
Page generated at 2024-01-28 04:26:33. Version ac07

Copyright 2024 Attilla Danko


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