Springfield
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Springfield clear sky chart from 2005-11-06 to 2024-01-12.

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%
24323
23%
74705
14%
24259
48%
24259
29%
45849

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
23%
950
21%
2458
6%
946
34%
946
26%
1645
January11th to 20thNight
19%
906
23%
2354
7%
906
31%
906
27%
1559
January21st to endNight
19%
990
24%
2574
6%
990
31%
990
27%
1713
February1st to 10thNight
18%
900
18%
2340
3%
900
27%
900
25%
1602
February11th to 20thNight
18%
857
19%
2252
5%
853
27%
853
25%
1505
February21st to endNight
17%
538
23%
1722
6%
538
31%
538
20%
1097
March1st to 10thNight
24%
540
23%
1980
10%
540
39%
540
21%
1186
March11th to 20thNight
27%
540
18%
1980
11%
540
36%
540
17%
1303
March21st to endNight
22%
594
14%
2178
8%
594
31%
594
16%
1478
April1st to 10thNight
30%
540
24%
1828
12%
540
46%
540
30%
1020
April11th to 20thNight
29%
533
24%
1775
15%
533
44%
533
27%
1060
April21st to endNight
27%
540
17%
1800
8%
540
41%
540
21%
1179
May1st to 10thNight
37%
540
19%
1656
13%
540
47%
540
27%
1036
May11th to 20thNight
46%
531
20%
1594
17%
531
52%
531
30%
991
May21st to endNight
46%
584
17%
1656
12%
582
52%
582
26%
1104
June1st to 10thNight
67%
540
21%
1440
17%
540
70%
540
42%
832
June11th to 20thNight
64%
540
25%
1440
19%
540
68%
540
45%
820
June21st to endNight
67%
540
28%
1440
20%
540
72%
540
56%
733
July1st to 10thNight
74%
525
17%
1562
18%
525
75%
525
38%
899
July11th to 20thNight
79%
522
23%
1566
24%
522
81%
522
49%
795
July21st to endNight
74%
591
25%
1673
27%
558
77%
558
39%
942
August1st to 10thNight
75%
537
23%
1601
26%
534
76%
534
38%
901
August11th to 20thNight
74%
534
28%
1655
30%
534
76%
534
41%
888
August21st to endNight
75%
594
26%
1980
32%
594
77%
594
40%
1033
September1st to 10thNight
68%
540
25%
1800
27%
540
72%
540
37%
968
September11th to 20thNight
67%
540
30%
1855
31%
540
71%
540
34%
1012
September21st to endNight
58%
594
30%
2034
27%
594
65%
594
38%
1055
October1st to 10thNight
55%
720
28%
2160
20%
720
61%
720
42%
1162
October11th to 20thNight
35%
720
30%
2160
14%
720
49%
720
35%
1240
October21st to endNight
35%
792
26%
2376
14%
792
45%
792
28%
1456
November1st to 10thNight
35%
740
32%
2220
16%
740
51%
740
37%
1232
November11th to 20thNight
30%
779
28%
2411
12%
779
46%
779
31%
1387
November21st to endNight
29%
950
23%
2660
10%
950
40%
950
28%
1701
December1st to 10thNight
25%
950
21%
2660
7%
950
38%
950
25%
1737
December11th to 20thNight
23%
949
21%
3154
9%
948
33%
948
19%
2100
December21st to endNight
19%
1043
13%
4711
7%
1026
32%
1026
12%
3478

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%3445%7%43%
74623
Night
12%7%35%42445%7%48%
75080
TransparencyDay
39%6%12%24%16%3
74346
Night
36%6%11%24%19%3
74877
SeeingDay
15%10%26%27%17%5%
14375
Night
15%10%31%30%13%1
24326

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
12%8%35%6%33345%48%
1707
11th to 20thDay
13%10%5%6%5%3445%6%39%
1629
21st to endDay
14%8%46%42445%7%43%
1782
February1st to 10thDay
15%11%47%6%34445%37%
1620
11th to 20thDay
14%8%5%7%6%24446%41%
1596
21st to endDay
17%10%35%5%45%447%37%
1547
March1st to 10thDay
14%9%5%5%5%23446%43%
1980
11th to 20thDay
21%10%45%5%23346%37%
1980
21st to endDay
20%9%46%6%35%46%7%30%
2178
April1st to 10thDay
11%7%36%5%245%5%6%45%
2132
11th to 20thDay
17%9%35%5%3445%6%39%
2134
21st to endDay
21%7%36%5%44447%36%
2160
May1st to 10thDay
19%8%25%436%447%37%
2299
11th to 20thDay
15%5%25%6%45%45%7%42%
2302
21st to endDay
12%6%35%6%5%6%6%8%9%35%
2616
June1st to 10thDay
9%425%5%25%5%5%10%47%
2520
11th to 20thDay
7%4245%46%6%6%10%47%
2520
21st to endDay
5%224435%5%7%9%54%
2520
July1st to 10thDay
9%5%25%5%46%6%8%11%39%
2347
11th to 20thDay
5%3245%36%6%7%10%49%
2340
21st to endDay
9%5%35%5%35%5%7%11%41%
2546
August1st to 10thDay
8%5%35%6%45%6%7%9%41%
2328
11th to 20thDay
9%5%25%6%45%6%8%8%43%
2243
21st to endDay
7%425%5%35%46%9%50%
2376
September1st to 10thDay
11%5%24435%447%49%
2160
11th to 20thDay
11%5%35%5%35%447%47%
2101
21st to endDay
7%424435%5%6%7%53%
1908
October1st to 10thDay
11%42442445%7%55%
1800
11th to 20thDay
14%7%25%423335%53%
1800
21st to endDay
19%6%25%423245%47%
1980
November1st to 10thDay
12%5%23323345%58%
1858
11th to 20thDay
14%7%34423446%49%
1763
21st to endDay
15%8%35%423236%48%
1520
December1st to 10thDay
12%10%36%5%34347%43%
1520
11th to 20thDay
13%11%37%5%34335%42%
1918
21st to endDay
14%16%7%8%6%34445%28%
2893
January1st to 10thNight
13%7%36%5%24445%46%
2458
11th to 20thNight
14%7%36%5%2445%5%46%
2354
21st to endNight
12%10%46%42335%5%45%
2574
February1st to 10thNight
14%9%46%424445%43%
2340
11th to 20thNight
15%8%36%5%23346%44%
2251
21st to endNight
15%8%5%5%5%2435%5%43%
1722
March1st to 10thNight
15%8%36%423347%46%
1980
11th to 20thNight
18%8%36%5%34445%39%
1980
21st to endNight
17%9%46%6%35%447%35%
2178
April1st to 10thNight
10%5%2443345%8%53%
1828
11th to 20thNight
12%8%35%43335%8%46%
1775
21st to endNight
20%6%35%5%335%6%7%39%
1800
May1st to 10thNight
15%5%3443445%6%47%
1656
11th to 20thNight
14%5%25%4235%5%7%48%
1593
21st to endNight
11%5%35%6%35%5%7%11%39%
1655
June1st to 10thNight
7%3244245%6%9%53%
1440
11th to 20thNight
5%4244345%7%10%54%
1440
21st to endNight
322233335%9%66%
1440
July1st to 10thNight
8%313435%5%8%9%51%
1607
11th to 20thNight
421332446%10%60%
1620
21st to endNight
6%424445%5%7%9%51%
1772
August1st to 10thNight
6%3145%345%6%10%52%
1611
11th to 20thNight
7%32332446%8%57%
1655
21st to endNight
5%3235%345%5%10%56%
1980
September1st to 10thNight
9%4245%33348%55%
1800
11th to 20thNight
9%5%25%42445%8%52%
1855
21st to endNight
9%424323346%59%
2034
October1st to 10thNight
8%42333345%7%60%
2160
11th to 20thNight
13%6%23323345%55%
2160
21st to endNight
17%8%24323345%49%
2376
November1st to 10thNight
12%5%23322336%59%
2220
11th to 20thNight
11%7%25%423346%53%
2411
21st to endNight
14%8%35%423445%48%
2660
December1st to 10thNight
15%9%36%32345%7%42%
2660
11th to 20thNight
14%9%5%8%433345%42%
3279
21st to endNight
17%17%6%7%5%24345%30%
4756

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
40%310%26%18%2
1708
11th to 20thDay
46%410%22%16%1
1629
21st to endDay
42%413%25%12%3
1782
February1st to 10thDay
50%5%10%22%11%1
1620
11th to 20thDay
46%5%10%21%15%4
1605
21st to endDay
49%47%21%13%6%
1547
March1st to 10thDay
43%5%9%19%19%5%
1980
11th to 20thDay
50%5%9%19%14%4
1980
21st to endDay
54%7%11%18%9%1
2178
April1st to 10thDay
38%7%12%23%19%1
2132
11th to 20thDay
46%5%13%19%14%3
2134
21st to endDay
50%6%9%23%11%1
2160
May1st to 10thDay
48%6%12%20%13%1
2299
11th to 20thDay
41%8%14%24%13%1
2306
21st to endDay
42%12%13%22%11%
2616
June1st to 10thDay
32%8%15%28%15%1
2520
11th to 20thDay
31%8%15%30%13%2
2520
21st to endDay
24%9%16%30%16%4
2520
July1st to 10thDay
35%10%17%22%13%2
2283
11th to 20thDay
27%10%15%27%19%3
2271
21st to endDay
35%8%15%30%10%1
2405
August1st to 10thDay
35%11%18%23%14%
2314
11th to 20thDay
36%8%14%28%14%1
2243
21st to endDay
31%8%13%23%20%6%
2376
September1st to 10thDay
35%6%13%25%14%7%
2160
11th to 20thDay
37%5%9%22%25%2
2101
21st to endDay
29%7%10%26%24%4
1908
October1st to 10thDay
30%5%11%25%24%5%
1800
11th to 20thDay
35%47%26%22%6%
1800
21st to endDay
40%49%25%17%6%
1980
November1st to 10thDay
30%5%9%28%22%5%
1858
11th to 20thDay
36%48%21%24%6%
1763
21st to endDay
40%49%23%21%2
1520
December1st to 10thDay
42%49%29%14%2
1520
11th to 20thDay
45%5%7%18%23%2
1915
21st to endDay
57%6%8%16%11%1
2893
January1st to 10thNight
41%5%10%23%19%3
2458
11th to 20thNight
41%411%26%17%1
2354
21st to endNight
41%411%25%16%3
2574
February1st to 10thNight
44%5%11%23%14%3
2340
11th to 20thNight
43%410%22%17%3
2252
21st to endNight
44%310%21%15%6%
1722
March1st to 10thNight
41%49%20%19%7%
1980
11th to 20thNight
46%7%10%18%17%3
1980
21st to endNight
50%5%10%22%12%1
2178
April1st to 10thNight
31%6%12%26%22%4
1828
11th to 20thNight
36%6%12%22%18%5%
1775
21st to endNight
44%6%11%23%16%1
1800
May1st to 10thNight
39%6%12%25%17%2
1656
11th to 20thNight
35%8%14%25%15%2
1594
21st to endNight
38%10%16%24%11%1
1656
June1st to 10thNight
26%7%16%30%18%2
1440
11th to 20thNight
23%8%15%30%20%3
1440
21st to endNight
17%5%19%32%20%6%
1440
July1st to 10thNight
27%9%18%27%17%3
1562
11th to 20thNight
19%7%16%30%27%2
1566
21st to endNight
26%8%15%35%15%1
1673
August1st to 10thNight
26%8%16%34%14%1
1601
11th to 20thNight
25%6%14%30%23%1
1655
21st to endNight
24%7%15%26%22%7%
1980
September1st to 10thNight
28%5%14%27%19%6%
1800
11th to 20thNight
30%6%11%24%26%4
1855
21st to endNight
27%5%10%25%30%4
2034
October1st to 10thNight
25%6%11%26%27%6%
2160
11th to 20thNight
32%48%24%25%6%
2160
21st to endNight
38%48%22%22%7%
2376
November1st to 10thNight
28%410%26%24%7%
2220
11th to 20thNight
33%47%25%25%6%
2411
21st to endNight
39%48%24%22%3
2660
December1st to 10thNight
42%5%11%23%18%2
2660
11th to 20thNight
46%47%21%20%2
3281
21st to endNight
56%6%10%16%9%2
4756

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%18%39%18%3
270
11th to 20thDay
25%21%39%14%2
243
21st to endDay
17%20%45%14%3
264
February1st to 10thDay
20%19%46%13%2
240
11th to 20thDay
25%27%30%15%3
240
21st to endDay
29%24%34%12%2
198
March1st to 10thDay
23%23%34%19%2
240
11th to 20thDay
29%15%32%20%3
240
21st to endDay
28%21%39%10%2
264
April1st to 10thDay
19%15%41%21%41
392
11th to 20thDay
24%17%35%19%5%
412
21st to endDay
24%17%31%21%6%1
420
May1st to 10thDay
22%12%31%26%8%1
562
11th to 20thDay
17%10%30%27%13%3
625
21st to endDay
13%7%31%26%16%6%
679
June1st to 10thDay
10%319%31%29%9%
630
11th to 20thDay
7%318%37%29%5%
630
21st to endDay
6%328%36%23%5%
630
July1st to 10thDay
10%314%29%32%12%
621
11th to 20thDay
5%414%36%33%9%
618
21st to endDay
9%211%35%30%13%
684
August1st to 10thDay
9%411%40%30%5%
626
11th to 20thDay
10%214%35%32%7%
557
21st to endDay
11%111%28%37%12%
495
September1st to 10thDay
12%110%36%30%10%
450
11th to 20thDay
9%217%36%26%10%
391
21st to endDay
9%425%33%23%7%
270
October1st to 10thDay
11%9%27%31%17%4
270
11th to 20thDay
15%16%36%25%7%1
270
21st to endDay
29%16%27%24%31
297
November1st to 10thDay
14%13%38%23%10%2
270
11th to 20thDay
16%21%30%24%7%1
270
21st to endDay
22%17%34%21%5%1
270
December1st to 10thDay
16%14%44%17%6%3
270
11th to 20thDay
21%17%39%19%5%
270
21st to endDay
18%27%38%14%2
297
January1st to 10thNight
17%19%38%21%5%
950
11th to 20thNight
19%18%41%18%4
906
21st to endNight
16%18%42%21%2
990
February1st to 10thNight
20%16%44%18%3
900
11th to 20thNight
21%17%41%19%2
857
21st to endNight
22%21%37%18%2
538
March1st to 10thNight
19%16%36%24%4
540
11th to 20thNight
23%15%33%23%5%
540
21st to endNight
22%16%37%22%41
594
April1st to 10thNight
14%15%39%29%4
540
11th to 20thNight
17%12%39%26%5%
533
21st to endNight
23%11%37%22%7%
540
May1st to 10thNight
16%6%37%33%9%
540
11th to 20thNight
15%6%29%32%17%1
531
21st to endNight
12%431%31%20%2
584
June1st to 10thNight
7%416%43%30%1
540
11th to 20thNight
6%223%46%22%1
540
21st to endNight
2123%49%24%1
540
July1st to 10thNight
8%110%42%35%5%
525
11th to 20thNight
3111%44%37%4
522
21st to endNight
7%18%47%34%4
591
August1st to 10thNight
7%29%49%30%3
537
11th to 20thNight
8%112%50%25%3
534
21st to endNight
5%112%41%37%4
594
September1st to 10thNight
10%214%42%30%3
540
11th to 20thNight
11%213%43%28%3
540
21st to endNight
12%421%40%21%3
594
October1st to 10thNight
9%5%29%33%21%3
720
11th to 20thNight
17%8%36%30%7%
720
21st to endNight
22%11%29%28%10%
792
November1st to 10thNight
14%10%39%28%10%
740
11th to 20thNight
15%14%38%26%7%
779
21st to endNight
20%13%36%24%7%
950
December1st to 10thNight
21%13%39%23%5%
950
11th to 20thNight
22%14%36%25%3
950
21st to endNight
20%18%40%21%2
1045
Page generated at 2024-01-08 21:31:28. Version ac07

Copyright 2024 Attilla Danko


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