Eldorado Star Party
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Eldorado Star Party clear sky chart from 2005-11-05 to 2019-06-10.

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
51%
17766
30%
53943
19%
17723
61%
17723
41%
28816

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
43%
1032
31%
2703
14%
1031
54%
1031
41%
1585
January16th to endNight
44%
896
35%
2688
19%
896
58%
896
39%
1456
February1st to 15thNight
38%
824
31%
2468
15%
818
52%
818
38%
1332
February16th to endNight
28%
736
31%
2206
10%
736
45%
736
36%
1200
March1st to 15thNight
32%
784
30%
2464
12%
784
49%
784
34%
1383
March16th to endNight
32%
672
28%
2464
15%
672
50%
672
35%
1244
April1st to 15thNight
29%
629
31%
2123
14%
629
50%
629
39%
1071
April16th to endNight
33%
624
32%
2079
14%
624
58%
624
44%
1019
May1st to 15thNight
33%
630
27%
1929
17%
630
49%
630
38%
1062
May16th to endNight
43%
657
26%
1972
16%
657
58%
657
40%
1085
June1st to 15thNight
62%
612
25%
1836
20%
612
72%
612
54%
879
June16th to endNight
71%
585
25%
1755
26%
585
73%
585
47%
909
July1st to 15thNight
80%
555
23%
1665
26%
555
81%
555
46%
876
July16th to endNight
86%
612
30%
1807
35%
579
88%
579
56%
838
August1st to 15thNight
89%
575
31%
1908
39%
572
90%
572
51%
878
August16th to endNight
79%
621
24%
2070
28%
621
80%
621
38%
1114
September1st to 15thNight
77%
585
25%
2090
29%
585
78%
585
34%
1148
September16th to endNight
69%
582
26%
2145
27%
582
72%
582
31%
1188
October1st to 15thNight
66%
585
34%
2145
33%
585
71%
585
42%
1013
October16th to endNight
58%
725
36%
2389
25%
725
67%
725
44%
1183
November1st to 15thNight
54%
1025
31%
2665
15%
1025
61%
1025
49%
1466
November16th to endNight
50%
1050
34%
2730
16%
1050
59%
1050
47%
1510
December1st to 15thNight
46%
1050
34%
2730
17%
1050
55%
1050
41%
1608
December16th to endNight
39%
1120
28%
2912
12%
1120
49%
1120
38%
1769

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
9%424424346%54%
54558
Night
7%313323347%58%
54149
Cloud CoverDay
9%424424346%54%
54556
Night
7%313323347%58%
54149
TransparencyDay
30%49%21%22%11%
54263
Night
25%410%22%22%14%
53948
SeeingDay
10%423%33%22%5%
7604
Night
9%430%39%15%1
17772

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 15thDay
11%5%23323236%54%
1906
16th to endDay
8%413323345%59%
2240
February1st to 15thDay
8%424323337%56%
2050
16th to endDay
9%423323445%57%
1840
March1st to 15thDay
11%424323345%51%
2156
16th to endDay
10%5%14323335%56%
2464
April1st to 15thDay
7%214423347%58%
2481
16th to endDay
8%423313336%58%
2486
May1st to 15thDay
10%42442335%7%49%
2681
16th to endDay
10%5%24424347%50%
2846
June1st to 15thDay
5%312313448%60%
2653
16th to endDay
7%42343445%8%51%
2535
July1st to 15thDay
7%4245%36%5%47%47%
2535
16th to endDay
32135%35%5%6%8%53%
2597
August1st to 15thDay
3213435%5%5%8%57%
2294
16th to endDay
7%4146%45%5%6%9%44%
2484
September1st to 15thDay
12%5%25%6%45%5%5%6%39%
2200
16th to endDay
11%5%25%5%34346%48%
2145
October1st to 15thDay
9%414313346%56%
2145
16th to endDay
10%31221223464%
2171
November1st to 15thDay
8%414222347%56%
1853
16th to endDay
8%413212245%61%
1890
December1st to 15thDay
14%5%14313335%52%
1890
16th to endDay
11%7%23222345%54%
2016
January1st to 15thNight
9%5%23313235%57%
2703
16th to endNight
8%423323435%59%
2688
February1st to 15thNight
8%6%22313247%57%
2462
16th to endNight
8%42432335%6%56%
2206
March1st to 15thNight
11%413323446%53%
2464
16th to endNight
7%413323346%58%
2464
April1st to 15thNight
7%31322335%8%59%
2123
16th to endNight
6%312213335%65%
2079
May1st to 15thNight
7%323324446%56%
1928
16th to endNight
7%22331346%8%55%
1971
June1st to 15thNight
211221346%9%64%
1836
16th to endNight
41331435%9%60%
1755
July1st to 15thNight
421331436%10%57%
1755
16th to endNight
221221335%11%63%
1920
August1st to 15thNight
211222435%9%66%
1919
16th to endNight
6%3123245%6%11%51%
2070
September1st to 15thNight
6%32442445%9%52%
2090
16th to endNight
9%4143235%6%8%48%
2145
October1st to 15thNight
8%313222336%63%
2145
16th to endNight
7%31331233465%
2389
November1st to 15thNight
7%413312235%64%
2665
16th to endNight
7%313212345%63%
2730
December1st to 15thNight
11%6%13313246%56%
2730
16th to endNight
8%5%34423346%53%
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
11%5%23322236%54%
1906
16th to endDay
8%413313345%59%
2240
February1st to 15thDay
8%424323337%56%
2050
16th to endDay
9%423324345%57%
1840
March1st to 15thDay
12%424323446%51%
2156
16th to endDay
10%5%24323235%56%
2462
April1st to 15thDay
7%224323346%59%
2481
16th to endDay
8%423313336%58%
2486
May1st to 15thDay
10%425%42335%7%49%
2681
16th to endDay
10%424424446%51%
2846
June1st to 15thDay
5%212313447%61%
2653
16th to endDay
7%4243245%5%7%51%
2535
July1st to 15thDay
8%4145%46%45%7%47%
2535
16th to endDay
4213435%5%6%7%54%
2597
August1st to 15thDay
3213335%5%5%8%57%
2294
16th to endDay
8%3146%35%5%5%9%45%
2484
September1st to 15thDay
13%5%26%6%36%5%5%6%39%
2200
16th to endDay
11%5%245%3435%6%47%
2145
October1st to 15thDay
9%414413346%56%
2145
16th to endDay
10%31221223365%
2171
November1st to 15thDay
8%5%13222347%57%
1853
16th to endDay
8%413223235%61%
1890
December1st to 15thDay
14%5%13213345%53%
1890
16th to endDay
10%7%24312345%54%
2016
January1st to 15thNight
9%5%24323236%57%
2703
16th to endNight
8%423323345%59%
2688
February1st to 15thNight
8%6%23312247%57%
2462
16th to endNight
8%5%1432335%6%56%
2206
March1st to 15thNight
11%5%13323446%53%
2464
16th to endNight
7%41332435%5%59%
2464
April1st to 15thNight
7%313213347%59%
2123
16th to endNight
6%312213345%65%
2079
May1st to 15thNight
7%323424446%56%
1928
16th to endNight
7%32232345%8%55%
1971
June1st to 15thNight
211221346%9%64%
1836
16th to endNight
411232435%9%60%
1755
July1st to 15thNight
421322337%10%57%
1755
16th to endNight
211121335%11%63%
1920
August1st to 15thNight
111222345%8%65%
1919
16th to endNight
6%3123246%6%12%51%
2070
September1st to 15thNight
6%32442345%9%52%
2090
16th to endNight
10%41432447%8%49%
2145
October1st to 15thNight
8%313212236%63%
2145
16th to endNight
7%31231232465%
2389
November1st to 15thNight
7%413212235%64%
2665
16th to endNight
7%313212335%63%
2730
December1st to 15thNight
11%5%13313246%56%
2730
16th to endNight
8%5%35%413336%53%
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
33%2421%24%14%
1907
16th to endDay
26%36%15%30%17%
2240
February1st to 15thDay
30%36%17%22%20%
2051
16th to endDay
29%3416%28%17%
1840
March1st to 15thDay
34%36%17%20%17%
2156
16th to endDay
31%38%18%23%15%
2464
April1st to 15thDay
26%47%18%24%19%
2481
16th to endDay
28%38%20%21%18%
2486
May1st to 15thDay
34%5%9%18%20%12%
2681
16th to endDay
34%49%23%19%8%
2850
June1st to 15thDay
22%5%10%28%25%7%
2653
16th to endDay
29%6%13%23%20%4
2535
July1st to 15thDay
34%6%15%27%13%1
2396
16th to endDay
22%8%18%31%17%1
2448
August1st to 15thDay
22%6%17%32%19%2
2281
16th to endDay
34%7%16%23%15%2
2484
September1st to 15thDay
44%6%11%18%14%4
2200
16th to endDay
36%5%11%18%20%8%
2145
October1st to 15thDay
29%5%11%22%21%10%
2145
16th to endDay
24%3414%31%21%
2171
November1st to 15thDay
27%310%24%20%13%
1853
16th to endDay
26%35%15%26%22%
1890
December1st to 15thDay
34%36%18%24%13%
1890
16th to endDay
33%26%19%28%10%
2016
January1st to 15thNight
30%26%17%25%18%
2703
16th to endNight
27%35%16%26%20%
2688
February1st to 15thNight
27%37%15%22%22%
2472
16th to endNight
28%35%16%26%19%
2206
March1st to 15thNight
31%37%17%22%17%
2464
16th to endNight
27%410%22%19%16%
2464
April1st to 15thNight
24%410%21%17%21%
2123
16th to endNight
21%410%25%21%17%
2079
May1st to 15thNight
28%411%24%19%12%
1929
16th to endNight
25%7%13%25%21%6%
1973
June1st to 15thNight
16%5%15%29%26%5%
1836
16th to endNight
20%7%13%30%21%6%
1755
July1st to 15thNight
21%7%18%31%18%2
1665
16th to endNight
13%6%20%36%20%2
1807
August1st to 15thNight
15%6%14%32%26%3
1908
16th to endNight
24%8%17%28%17%3
2070
September1st to 15thNight
28%7%14%24%20%4
2090
16th to endNight
30%6%13%23%15%10%
2145
October1st to 15thNight
23%313%26%22%10%
2145
16th to endNight
23%35%15%28%23%
2389
November1st to 15thNight
24%28%24%25%14%
2665
16th to endNight
24%36%15%25%24%
2730
December1st to 15thNight
30%27%20%23%15%
2730
16th to endNight
32%37%16%24%16%
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
15%435%32%10%2
180
16th to endDay
9%11%30%32%13%1
192
February1st to 15thDay
18%6%36%24%12%1
180
16th to endDay
14%5%47%25%6%
159
March1st to 15thDay
15%7%51%17%8%
180
16th to endDay
6%5%41%31%14%1
192
April1st to 15thDay
6%14%41%31%5%
360
16th to endDay
7%12%40%28%8%1
378
May1st to 15thDay
13%7%38%30%8%
578
16th to endDay
13%5%33%35%10%1
677
June1st to 15thDay
5%219%50%20%1
616
16th to endDay
8%113%42%29%5%
570
July1st to 15thDay
7%16%41%36%7%
550
16th to endDay
3434%45%12%
518
August1st to 15thDay
4331%46%14%
359
16th to endDay
9%18%28%39%14%
396
September1st to 15thDay
12%5%24%39%17%
235
16th to endDay
20%15%26%33%12%
180
October1st to 15thDay
8%10%40%37%3
180
16th to endDay
21%219%26%25%4
192
November1st to 15thDay
16%6%28%24%21%2
180
16th to endDay
17%11%21%23%19%6%
180
December1st to 15thDay
23%6%25%28%13%3
180
16th to endDay
17%9%42%23%6%
192
January1st to 15thNight
12%5%33%39%9%
1036
16th to endNight
11%6%33%38%9%
896
February1st to 15thNight
12%8%36%34%7%
824
16th to endNight
11%10%47%27%2
736
March1st to 15thNight
14%7%44%28%5%
784
16th to endNight
6%8%50%30%3
672
April1st to 15thNight
6%10%51%27%3
629
16th to endNight
46%52%30%5%
624
May1st to 15thNight
6%8%49%29%5%
630
16th to endNight
8%341%35%10%
659
June1st to 15thNight
231%55%9%
612
16th to endNight
3119%55%18%1
585
July1st to 15thNight
6%7%55%27%1
555
16th to endNight
15%54%35%1
612
August1st to 15thNight
2344%45%4
575
16th to endNight
7%6%43%38%4
621
September1st to 15thNight
6%6%42%38%5%
585
16th to endNight
10%111%47%26%2
582
October1st to 15thNight
8%219%48%20%
585
16th to endNight
8%326%39%20%1
725
November1st to 15thNight
9%328%40%17%1
1025
16th to endNight
9%430%37%15%1
1050
December1st to 15thNight
14%5%30%38%10%
1050
16th to endNight
12%7%36%34%9%
1120
Page generated at 2019-06-10 18:29:46. Version ac04

Copyright 2019 A. Danko


Eldorado Star Party Clear Sky Chart |Charts Home