Cedarville
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cedarville clear sky chart from 2005-11-06 to 2024-11-02.

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
63%
23879
22%
93686
22%
23746
66%
23746
29%
50893

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
49%
750
10%
4369
12%
736
54%
736
12%
2843
January11th to 20thNight
49%
751
10%
4409
14%
740
52%
740
11%
3188
January21st to endNight
51%
833
12%
4523
22%
814
55%
814
13%
3127
February1st to 10thNight
56%
760
18%
2470
18%
760
59%
760
28%
1507
February11th to 20thNight
55%
741
18%
2289
18%
740
59%
740
28%
1435
February21st to endNight
53%
628
17%
1884
17%
628
56%
628
27%
1209
March1st to 10thNight
44%
753
14%
3720
11%
744
48%
744
13%
2446
March11th to 20thNight
54%
749
21%
3502
17%
740
57%
740
24%
1678
March21st to endNight
47%
823
10%
3538
9%
814
50%
814
17%
2226
April1st to 10thNight
55%
760
18%
1900
10%
760
57%
760
32%
1265
April11th to 20thNight
55%
751
20%
1879
10%
751
58%
751
36%
1207
April21st to endNight
61%
760
18%
1900
11%
760
62%
760
41%
1150
May1st to 10thNight
58%
506
28%
2628
20%
498
63%
498
25%
1250
May11th to 20thNight
64%
366
25%
2395
26%
364
67%
364
28%
806
May21st to endNight
60%
399
16%
2725
18%
399
64%
399
21%
1034
June1st to 10thNight
69%
380
19%
1520
27%
380
71%
380
32%
773
June11th to 20thNight
73%
380
28%
1520
39%
380
78%
380
46%
641
June21st to endNight
82%
380
28%
1520
41%
380
86%
380
54%
582
July1st to 10thNight
90%
360
38%
2064
45%
360
91%
360
62%
501
July11th to 20thNight
90%
362
33%
1950
51%
359
93%
359
50%
648
July21st to endNight
89%
406
34%
2086
50%
383
91%
383
52%
640
August1st to 10thNight
87%
528
39%
2280
33%
523
88%
523
46%
934
August11th to 20thNight
83%
686
33%
2426
24%
679
85%
679
63%
906
August21st to endNight
87%
818
38%
2915
26%
814
88%
814
66%
1093
September1st to 10thNight
85%
760
43%
1900
28%
760
87%
760
73%
899
September11th to 20thNight
79%
760
41%
1914
30%
760
81%
760
63%
974
September21st to endNight
80%
760
39%
2092
35%
760
82%
760
61%
1001
October1st to 10thNight
71%
760
31%
2280
30%
760
77%
760
50%
1136
October11th to 20thNight
73%
760
31%
2280
32%
760
77%
760
50%
1130
October21st to endNight
69%
836
29%
2594
29%
836
74%
836
45%
1331
November1st to 10thNight
60%
748
23%
2430
24%
748
63%
748
28%
1466
November11th to 20thNight
58%
760
20%
2470
18%
760
61%
760
28%
1509
November21st to endNight
56%
760
18%
2654
18%
760
60%
760
30%
1504
December1st to 10thNight
53%
760
17%
2660
15%
760
57%
760
24%
1639
December11th to 20thNight
49%
759
14%
3205
14%
759
52%
759
16%
2091
December21st to endNight
39%
826
9%
4795
13%
817
42%
817
10%
3124

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
36%26%5%4445%7%54%
101391
Night
37%37%5%5%5%46%8%48%
97759
TransparencyDay
29%49%20%21%17%
101133
Night
32%412%21%19%12%
97606
SeeingDay
5%7%22%30%24%11%
14837
Night
6%418%44%25%3
24029

By Month

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 10thDay
212%6%14%10%8%8%5%7%7%22%
2539
11th to 20thDay
410%5%15%11%11%7%6%6%7%18%
2540
21st to endDay
6%15%6%13%8%6%6%46%7%23%
3080
February1st to 10thDay
38%38%6%6%7%7%7%11%36%
1710
11th to 20thDay
26%39%7%6%7%5%7%11%36%
1780
21st to endDay
28%38%7%7%7%6%8%10%35%
1570
March1st to 10thDay
211%5%13%9%8%7%5%6%7%26%
3138
11th to 20thDay
37%27%45%446%10%47%
3445
21st to endDay
311%6%11%8%7%6%5%7%8%30%
4062
April1st to 10thDay
5%11%49%7%5%5%46%8%36%
2280
11th to 20thDay
5%9%37%6%5%5%45%8%44%
2249
21st to endDay
5%7%37%5%5%5%46%8%45%
2280
May1st to 10thDay
6%8%37%44335%6%51%
4202
11th to 20thDay
3414333348%64%
4377
21st to endDay
5%5%26%44445%7%55%
4813
June1st to 10thDay
5%5%26%5%45%5%7%9%47%
2660
11th to 20thDay
3414234346%65%
2660
21st to endDay
3213233245%74%
2660
July1st to 10thDay
11112113386%
4420
11th to 20thDay
221222223478%
4420
21st to endDay
112223245%78%
4790
August1st to 10thDay
221322335%6%70%
4132
11th to 20thDay
11111223385%
3811
21st to endDay
221112222482%
4180
September1st to 10thDay
2112222235%78%
2280
11th to 20thDay
3214334446%66%
2266
21st to endDay
3313233235%71%
2085
October1st to 10thDay
6%414334346%63%
1900
11th to 20thDay
35%15%33435%6%61%
1900
21st to endDay
35%16%445%45%7%56%
2002
November1st to 10thDay
6%7%48%5%5%5%47%8%42%
1683
11th to 20thDay
46%38%7%6%6%6%7%11%36%
1710
21st to endDay
36%26%7%6%5%5%7%11%41%
1525
December1st to 10thDay
36%39%8%6%5%48%10%38%
1520
11th to 20thDay
5%11%411%9%7%7%5%8%10%24%
1928
21st to endDay
48%5%14%9%6%6%6%9%10%24%
2794
January1st to 10thNight
29%5%12%8%10%8%6%8%10%22%
4406
11th to 20thNight
312%415%12%11%7%5%6%7%19%
4420
21st to endNight
414%6%14%9%7%7%47%8%21%
4583
February1st to 10thNight
37%37%6%5%6%6%10%13%33%
2470
11th to 20thNight
28%39%6%7%6%5%9%13%32%
2287
21st to endNight
28%38%7%7%6%5%8%11%34%
1884
March1st to 10thNight
211%6%12%9%8%7%5%7%8%24%
3736
11th to 20thNight
37%37%6%5%5%5%11%15%35%
3531
21st to endNight
310%310%7%7%7%6%8%11%28%
3591
April1st to 10thNight
47%37%7%5%7%5%9%9%38%
1900
11th to 20thNight
39%26%6%6%5%46%8%45%
1879
21st to endNight
5%8%25%34437%9%49%
1900
May1st to 10thNight
47%26%435%37%6%52%
2746
11th to 20thNight
331432337%9%61%
2516
21st to endNight
45%25%44336%7%56%
2762
June1st to 10thNight
6%6%26%44445%8%51%
1520
11th to 20thNight
45%13232346%67%
1520
21st to endNight
2312333335%73%
1520
July1st to 10thNight
1111223386%
2540
11th to 20thNight
211222224479%
2540
21st to endNight
1112222245%79%
2761
August1st to 10thNight
2213333246%71%
2802
11th to 20thNight
111212113383%
3035
21st to endNight
12112223482%
3498
September1st to 10thNight
211222213481%
1900
11th to 20thNight
222322325%6%70%
1914
21st to endNight
331222335%7%71%
2092
October1st to 10thNight
4414333245%67%
2280
11th to 20thNight
3413343347%65%
2280
21st to endNight
45%2443435%8%58%
2594
November1st to 10thNight
5%7%27%6%5%6%5%6%8%43%
2430
11th to 20thNight
46%28%6%5%7%6%8%11%37%
2470
21st to endNight
27%27%6%5%6%5%8%11%41%
2654
December1st to 10thNight
47%39%6%5%5%6%7%10%37%
2660
11th to 20thNight
6%10%411%7%6%7%6%9%13%21%
3276
21st to endNight
5%11%413%8%8%8%6%7%9%23%
4862

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
55%5%16%20%4
2539
11th to 20thDay
60%5%13%11%7%3
2540
21st to endDay
57%414%18%6%2
3080
February1st to 10thDay
38%7%17%25%10%3
1710
11th to 20thDay
37%7%18%24%12%2
1789
21st to endDay
38%9%17%25%9%3
1570
March1st to 10thDay
53%6%11%17%13%1
3138
11th to 20thDay
30%413%39%14%1
3445
21st to endDay
49%5%16%22%7%1
4062
April1st to 10thDay
44%6%16%21%11%2
2280
11th to 20thDay
38%5%12%28%15%3
2252
21st to endDay
36%5%15%27%16%2
2280
May1st to 10thDay
31%410%32%20%3
4202
11th to 20thDay
21%36%22%42%6%
4380
21st to endDay
29%49%35%20%2
4814
June1st to 10thDay
32%5%11%28%19%4
2660
11th to 20thDay
20%38%23%33%13%
2660
21st to endDay
14%3419%36%24%
2660
July1st to 10thDay
6%227%18%65%
4351
11th to 20thDay
13%217%19%58%
4345
21st to endDay
12%219%32%44%
4639
August1st to 10thDay
15%2210%26%45%
4116
11th to 20thDay
7%2110%37%42%
3849
21st to endDay
10%1117%38%33%
4179
September1st to 10thDay
12%2211%31%43%
2280
11th to 20thDay
19%36%20%29%23%
2266
21st to endDay
17%36%22%31%22%
2085
October1st to 10thDay
25%27%21%26%19%
1900
11th to 20thDay
24%39%25%27%12%
1900
21st to endDay
26%413%25%22%10%
2002
November1st to 10thDay
38%5%12%20%20%5%
1683
11th to 20thDay
37%6%16%24%15%2
1710
21st to endDay
33%7%17%22%19%4
1525
December1st to 10thDay
39%8%14%22%14%3
1520
11th to 20thDay
48%6%21%15%10%1
1928
21st to endDay
49%6%16%20%9%
2794
January1st to 10thNight
50%6%20%20%4
4406
11th to 20thNight
57%6%13%13%7%4
4420
21st to endNight
56%313%18%8%2
4583
February1st to 10thNight
36%7%17%23%14%2
2470
11th to 20thNight
37%7%16%23%14%2
2289
21st to endNight
37%9%19%22%12%2
1884
March1st to 10thNight
51%5%15%16%12%1
3736
11th to 20thNight
32%410%37%17%
3531
21st to endNight
46%5%19%23%7%1
3591
April1st to 10thNight
37%8%19%23%11%3
1900
11th to 20thNight
35%5%18%25%14%3
1879
21st to endNight
30%5%18%31%14%3
1900
May1st to 10thNight
30%311%30%19%6%
2746
11th to 20thNight
19%48%24%37%8%
2516
21st to endNight
26%314%36%20%1
2762
June1st to 10thNight
30%415%31%17%2
1520
11th to 20thNight
20%38%26%34%9%
1520
21st to endNight
15%35%20%36%22%
1520
July1st to 10thNight
5%238%19%62%
2500
11th to 20thNight
11%119%20%56%
2492
21st to endNight
10%239%34%43%
2674
August1st to 10thNight
16%2310%28%41%
2794
11th to 20thNight
9%2111%43%33%
3063
21st to endNight
9%1223%34%30%
3498
September1st to 10thNight
10%2212%30%43%
1900
11th to 20thNight
15%36%22%30%24%
1914
21st to endNight
15%3425%29%24%
2092
October1st to 10thNight
22%38%20%29%18%
2280
11th to 20thNight
20%410%26%27%13%
2280
21st to endNight
25%314%26%21%11%
2594
November1st to 10thNight
38%5%13%21%17%6%
2430
11th to 20thNight
36%8%15%22%18%2
2470
21st to endNight
34%6%16%21%19%4
2654
December1st to 10thNight
38%7%15%20%16%3
2660
11th to 20thNight
47%6%18%17%12%
3276
21st to endNight
53%414%18%10%1
4862

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
11%14%28%30%13%4
180
11th to 20thDay
5%9%21%34%24%7%
180
21st to endDay
8%323%34%22%10%
367
February1st to 10thDay
5%6%26%34%24%6%
370
11th to 20thDay
312%28%34%19%4
421
21st to endDay
6%9%26%36%19%4
382
March1st to 10thDay
8%10%32%33%15%2
460
11th to 20thDay
8%8%24%35%17%9%
460
21st to endDay
8%13%27%31%17%3
506
April1st to 10thDay
10%10%27%31%17%4
460
11th to 20thDay
7%12%26%32%17%6%
452
21st to endDay
6%11%23%30%23%7%
460
May1st to 10thDay
6%12%28%25%22%7%
463
11th to 20thDay
11%8%22%28%21%10%
488
21st to endDay
11%8%16%26%25%15%
529
June1st to 10thDay
5%8%18%28%28%13%
490
11th to 20thDay
5%9%29%24%23%9%
490
21st to endDay
25%19%29%27%19%
490
July1st to 10thDay
3217%28%33%17%
486
11th to 20thDay
1218%28%34%16%
484
21st to endDay
2315%32%32%17%
531
August1st to 10thDay
3217%29%29%20%
487
11th to 20thDay
25%18%28%28%18%
477
21st to endDay
3418%26%30%19%
539
September1st to 10thDay
3417%26%30%19%
490
11th to 20thDay
45%18%28%29%16%
490
21st to endDay
36%19%30%29%12%
490
October1st to 10thDay
6%9%19%26%26%15%
490
11th to 20thDay
6%10%21%23%27%14%
490
21st to endDay
5%10%22%32%20%11%
451
November1st to 10thDay
8%10%16%33%22%11%
273
11th to 20thDay
47%20%34%24%11%
270
21st to endDay
38%20%33%28%7%
183
December1st to 10thDay
411%17%35%21%12%
180
11th to 20thDay
7%422%38%22%7%
180
21st to endDay
5%9%20%37%24%5%
198
January1st to 10thNight
6%5%27%42%18%3
760
11th to 20thNight
5%7%28%36%21%3
760
21st to endNight
9%423%39%22%3
836
February1st to 10thNight
6%5%24%47%17%2
760
11th to 20thNight
5%5%23%48%16%3
744
21st to endNight
5%6%23%48%17%1
628
March1st to 10thNight
7%8%26%42%15%2
760
11th to 20thNight
8%6%20%40%23%3
760
21st to endNight
9%7%26%42%16%1
836
April1st to 10thNight
5%7%23%47%17%1
760
11th to 20thNight
7%7%24%40%19%4
751
21st to endNight
8%5%17%42%24%3
760
May1st to 10thNight
6%6%24%41%22%1
508
11th to 20thNight
9%214%39%30%5%
374
21st to endNight
10%314%39%30%3
411
June1st to 10thNight
7%313%45%31%2
380
11th to 20thNight
6%213%53%24%2
380
21st to endNight
210%53%34%1
380
July1st to 10thNight
1458%36%1
370
11th to 20thNight
116%59%33%
368
21st to endNight
11454%39%1
416
August1st to 10thNight
31349%41%3
534
11th to 20thNight
118%45%39%4
697
21st to endNight
28%49%37%4
836
September1st to 10thNight
228%46%38%5%
760
11th to 20thNight
4111%35%41%8%
760
21st to endNight
5%39%42%33%8%
760
October1st to 10thNight
5%313%43%31%4
760
11th to 20thNight
35%13%44%29%5%
760
21st to endNight
6%416%46%21%8%
836
November1st to 10thNight
7%5%18%44%21%4
748
11th to 20thNight
6%424%46%17%3
760
21st to endNight
45%24%45%19%4
760
December1st to 10thNight
6%7%22%43%18%3
760
11th to 20thNight
9%8%25%38%17%3
760
21st to endNight
9%8%30%41%11%1
836
Page generated at 2024-10-30 10:19:23. Version ac07

Copyright © 2024 Attilla Danko.


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