Yucca Valley
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Yucca Valley clear sky chart from 2005-11-06 to 2024-01-13.

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
72%
24779
40%
74388
31%
24735
80%
24735
63%
31913

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
59%
757
36%
2457
29%
756
70%
756
47%
1124
January11th to 20thNight
61%
728
39%
2352
31%
728
74%
728
49%
1048
January21st to endNight
52%
792
43%
2376
27%
792
71%
792
47%
1127
February1st to 10thNight
58%
720
41%
2160
30%
720
74%
720
51%
1003
February11th to 20thNight
59%
700
41%
2098
30%
700
76%
700
55%
943
February21st to endNight
55%
592
41%
1776
32%
592
70%
592
56%
783
March1st to 10thNight
55%
720
34%
2160
26%
720
70%
720
49%
1008
March11th to 20thNight
65%
720
39%
2044
29%
720
78%
720
62%
902
March21st to endNight
60%
792
39%
2114
24%
792
73%
792
60%
992
April1st to 10thNight
62%
720
40%
1800
23%
720
71%
720
60%
905
April11th to 20thNight
63%
711
43%
1779
21%
711
73%
711
71%
825
April21st to endNight
70%
713
45%
1793
23%
713
78%
713
77%
795
May1st to 10thNight
70%
540
45%
1620
31%
540
77%
540
75%
614
May11th to 20thNight
77%
531
44%
1595
32%
531
81%
531
76%
607
May21st to endNight
75%
583
42%
1746
32%
582
79%
582
82%
642
June1st to 10thNight
80%
540
38%
1620
31%
540
82%
540
76%
630
June11th to 20thNight
80%
540
40%
1620
35%
540
82%
540
83%
598
June21st to endNight
83%
540
38%
1620
33%
540
85%
540
79%
628
July1st to 10thNight
89%
525
37%
1575
33%
525
89%
525
81%
595
July11th to 20thNight
86%
522
36%
1566
31%
522
86%
522
68%
658
July21st to endNight
86%
591
38%
1674
32%
558
86%
558
62%
745
August1st to 10thNight
89%
705
39%
1770
25%
702
90%
702
78%
807
August11th to 20thNight
92%
712
42%
1780
27%
712
93%
712
81%
799
August21st to endNight
90%
792
45%
1980
32%
792
90%
792
78%
906
September1st to 10thNight
88%
720
42%
1840
32%
720
90%
720
73%
856
September11th to 20thNight
90%
720
49%
1980
42%
720
94%
720
87%
777
September21st to endNight
86%
720
48%
1980
41%
720
92%
720
84%
797
October1st to 10thNight
77%
720
45%
1980
35%
720
86%
720
72%
856
October11th to 20thNight
80%
720
51%
1980
42%
720
89%
720
79%
809
October21st to endNight
75%
792
45%
2491
40%
792
85%
792
71%
939
November1st to 10thNight
74%
740
42%
2405
39%
740
85%
740
67%
921
November11th to 20thNight
73%
760
43%
2470
38%
760
85%
760
67%
959
November21st to endNight
66%
760
42%
2470
36%
760
78%
760
54%
1071
December1st to 10thNight
64%
760
38%
2470
31%
760
75%
760
51%
1109
December11th to 20thNight
59%
759
36%
2890
28%
758
73%
758
41%
1299
December21st to endNight
53%
822
25%
4357
28%
817
68%
817
29%
1836

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
2212223346%75%
74862
Night
1212223346%75%
74909
TransparencyDay
12%3413%27%41%
74589
Night
11%3414%29%38%
74704
SeeingDay
5%13%26%32%18%7%
14424
Night
26%16%34%32%10%
24802

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
241342435%7%65%
1708
11th to 20thDay
332322445%7%66%
1647
21st to endDay
2314424347%66%
1980
February1st to 10thDay
1324324436%70%
1800
11th to 20thDay
111232445%8%68%
1750
21st to endDay
221232345%7%68%
1480
March1st to 10thDay
23222235%6%8%67%
1800
11th to 20thDay
2213324437%70%
1915
21st to endDay
1122135%47%74%
2239
April1st to 10thDay
2313312347%71%
2160
11th to 20thDay
1112212335%80%
2129
21st to endDay
111211347%79%
2164
May1st to 10thDay
1112212235%81%
2340
11th to 20thDay
11111223485%
2301
21st to endDay
11121123384%
2530
June1st to 10thDay
111211223483%
2340
11th to 20thDay
111112390%
2340
21st to endDay
211221212383%
2340
July1st to 10thDay
111222333478%
2340
11th to 20thDay
211232236%6%71%
2340
21st to endDay
33133345%7%7%62%
2545
August1st to 10thDay
1112312336%77%
2156
11th to 20thDay
111222345%6%75%
2122
21st to endDay
211212335%79%
2376
September1st to 10thDay
2112223445%75%
2120
11th to 20thDay
11111122389%
1980
21st to endDay
111111222385%
1980
October1st to 10thDay
1112212235%79%
1980
11th to 20thDay
1111123485%
1980
21st to endDay
111221223483%
1861
November1st to 10thDay
112212335%79%
1674
11th to 20thDay
1212322446%74%
1710
21st to endDay
2212322447%70%
1710
December1st to 10thDay
242434335%9%62%
1710
11th to 20thDay
2425%4245%7%8%56%
2169
21st to endDay
5%3245%345%6%8%55%
3146
January1st to 10thNight
132432445%8%64%
2457
11th to 20thNight
2314324447%67%
2352
21st to endNight
3313323446%67%
2376
February1st to 10thNight
2213324346%70%
2160
11th to 20thNight
121232445%6%70%
2098
21st to endNight
12123245%6%8%67%
1776
March1st to 10thNight
221332445%8%65%
2160
11th to 20thNight
111221445%8%70%
2044
21st to endNight
1113323347%72%
2114
April1st to 10thNight
1323223337%72%
1800
11th to 20thNight
121221224481%
1779
21st to endNight
111112236%82%
1793
May1st to 10thNight
11111335%84%
1620
11th to 20thNight
11112235%85%
1594
21st to endNight
111112488%
1746
June1st to 10thNight
11121132386%
1620
11th to 20thNight
111112289%
1620
21st to endNight
111111113386%
1620
July1st to 10thNight
11111222485%
1620
11th to 20thNight
1112222345%76%
1620
21st to endNight
221232345%6%71%
1773
August1st to 10thNight
2111212235%81%
1779
11th to 20thNight
11112245%82%
1780
21st to endNight
221111124382%
1980
September1st to 10thNight
111221233481%
1840
11th to 20thNight
111112291%
1980
21st to endNight
1111122389%
1980
October1st to 10thNight
111222235%80%
1980
11th to 20thNight
111111112388%
1980
21st to endNight
121223483%
2491
November1st to 10thNight
111222223480%
2405
11th to 20thNight
1112212345%78%
2470
21st to endNight
2213323446%70%
2470
December1st to 10thNight
3213424348%65%
2470
11th to 20thNight
242443446%10%58%
3041
21st to endNight
33244345%6%7%59%
4521

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
18%45%20%32%21%
1709
11th to 20thDay
16%35%16%35%24%
1647
21st to endDay
19%25%19%31%23%
1980
February1st to 10thDay
17%35%15%29%32%
1800
11th to 20thDay
13%3416%32%31%
1760
21st to endDay
14%35%18%32%27%
1480
March1st to 10thDay
14%3420%33%27%
1800
11th to 20thDay
15%4418%33%27%
1915
21st to endDay
9%35%24%34%25%
2239
April1st to 10thDay
15%2417%36%26%
2160
11th to 20thDay
8%2312%36%39%
2132
21st to endDay
8%2215%35%38%
2164
May1st to 10thDay
8%1214%35%39%
2340
11th to 20thDay
6%1210%34%46%
2304
21st to endDay
7%2313%34%42%
2530
June1st to 10thDay
7%218%29%53%
2340
11th to 20thDay
3116%18%70%
2340
21st to endDay
9%12410%74%
2340
July1st to 10thDay
11%217%14%64%
2276
11th to 20thDay
13%35%14%24%41%
2271
21st to endDay
18%5%7%16%22%33%
2404
August1st to 10thDay
10%349%20%54%
2141
11th to 20thDay
8%45%11%22%50%
2122
21st to endDay
10%329%24%52%
2376
September1st to 10thDay
13%448%16%55%
2120
11th to 20thDay
411425%65%
1980
21st to endDay
8%218%25%55%
1980
October1st to 10thDay
9%3211%28%48%
1980
11th to 20thDay
5%229%28%53%
1980
21st to endDay
7%138%26%54%
1861
November1st to 10thDay
9%2313%32%41%
1674
11th to 20thDay
12%2313%29%41%
1710
21st to endDay
14%2414%32%34%
1710
December1st to 10thDay
20%35%19%25%27%
1710
11th to 20thDay
21%5%10%22%24%18%
2168
21st to endDay
23%6%7%24%27%13%
3146
January1st to 10thNight
17%46%19%32%22%
2457
11th to 20thNight
16%45%18%30%26%
2352
21st to endNight
19%36%19%28%26%
2376
February1st to 10thNight
17%3317%26%35%
2160
11th to 20thNight
15%25%17%30%31%
2099
21st to endNight
13%35%19%31%28%
1776
March1st to 10thNight
17%45%20%31%24%
2160
11th to 20thNight
11%46%18%34%28%
2044
21st to endNight
12%36%18%38%22%
2114
April1st to 10thNight
15%3422%32%25%
1800
11th to 20thNight
9%2314%34%38%
1779
21st to endNight
6%2314%40%35%
1793
May1st to 10thNight
5%2219%34%39%
1620
11th to 20thNight
6%2311%37%41%
1595
21st to endNight
41316%40%36%
1746
June1st to 10thNight
7%2210%28%52%
1620
11th to 20thNight
4117%19%67%
1620
21st to endNight
7%11415%73%
1620
July1st to 10thNight
6%126%18%68%
1575
11th to 20thNight
11%25%14%25%43%
1566
21st to endNight
14%36%20%24%33%
1674
August1st to 10thNight
7%3210%24%54%
1770
11th to 20thNight
6%2311%28%50%
1780
21st to endNight
8%228%27%54%
1980
September1st to 10thNight
9%338%21%57%
1840
11th to 20thNight
4125%24%64%
1980
21st to endNight
4227%26%59%
1980
October1st to 10thNight
9%2212%31%44%
1980
11th to 20thNight
6%228%30%53%
1980
21st to endNight
7%238%24%56%
2491
November1st to 10thNight
9%2310%36%40%
2405
11th to 20thNight
10%1314%33%39%
2470
21st to endNight
15%3416%31%32%
2470
December1st to 10thNight
17%36%18%26%30%
2470
11th to 20thNight
20%410%19%29%19%
3041
21st to endNight
19%7%8%23%28%14%
4521

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
12%15%23%33%14%2
270
11th to 20thDay
14%13%22%31%17%3
255
21st to endDay
11%19%29%26%12%2
462
February1st to 10thDay
5%21%30%29%11%5%
420
11th to 20thDay
8%24%33%22%11%1
415
21st to endDay
10%29%25%25%10%1
346
March1st to 10thDay
10%26%29%23%10%2
420
11th to 20thDay
8%18%32%25%14%2
420
21st to endDay
9%23%33%26%7%2
462
April1st to 10thDay
7%18%27%25%17%5%
420
11th to 20thDay
5%25%32%21%13%4
412
21st to endDay
5%21%27%28%13%6%
420
May1st to 10thDay
5%16%32%30%12%5%
423
11th to 20thDay
117%27%35%14%7%
448
21st to endDay
215%29%32%13%8%
485
June1st to 10thDay
410%26%33%18%9%
450
11th to 20thDay
18%29%30%21%11%
450
21st to endDay
37%26%34%18%11%
450
July1st to 10thDay
2322%41%20%13%
446
11th to 20thDay
2117%44%20%16%
444
21st to endDay
3315%41%22%16%
487
August1st to 10thDay
3319%40%23%12%
447
11th to 20thDay
2216%40%27%13%
437
21st to endDay
1221%37%24%16%
495
September1st to 10thDay
3420%42%24%7%
450
11th to 20thDay
36%26%35%25%5%
450
21st to endDay
211%22%32%23%10%
450
October1st to 10thDay
49%31%32%20%4
450
11th to 20thDay
29%26%36%24%3
450
21st to endDay
411%25%30%25%5%
343
November1st to 10thDay
414%21%30%27%4
270
11th to 20thDay
310%26%31%26%4
270
21st to endDay
5%14%24%33%17%6%
270
December1st to 10thDay
6%12%30%30%19%3
270
11th to 20thDay
7%17%20%32%21%3
270
21st to endDay
9%18%31%23%16%2
297
January1st to 10thNight
5%9%20%34%22%10%
760
11th to 20thNight
48%21%36%23%8%
728
21st to endNight
7%10%23%33%22%5%
792
February1st to 10thNight
411%21%35%23%7%
720
11th to 20thNight
410%22%37%20%6%
704
21st to endNight
5%8%28%37%17%4
592
March1st to 10thNight
411%23%37%21%3
720
11th to 20thNight
38%21%32%26%9%
720
21st to endNight
49%23%38%21%6%
792
April1st to 10thNight
38%21%37%26%6%
720
11th to 20thNight
28%24%36%24%6%
711
21st to endNight
27%19%35%27%10%
713
May1st to 10thNight
18%19%38%30%5%
540
11th to 20thNight
5%15%37%36%7%
531
21st to endNight
15%18%40%30%7%
584
June1st to 10thNight
216%40%36%6%
540
11th to 20thNight
116%40%37%6%
540
21st to endNight
1112%38%40%9%
540
July1st to 10thNight
116%31%49%12%
525
11th to 20thNight
216%33%46%12%
522
21st to endNight
22430%50%11%
591
August1st to 10thNight
15%30%47%16%
705
11th to 20thNight
2323%51%21%
712
21st to endNight
31324%45%24%
792
September1st to 10thNight
12425%50%17%
720
11th to 20thNight
17%34%43%14%
720
21st to endNight
1210%33%41%14%
720
October1st to 10thNight
2315%39%36%6%
720
11th to 20thNight
2311%37%35%11%
720
21st to endNight
16%13%33%31%15%
792
November1st to 10thNight
18%14%35%31%12%
740
11th to 20thNight
2417%35%31%11%
760
21st to endNight
37%18%38%25%9%
760
December1st to 10thNight
46%20%38%25%7%
760
11th to 20thNight
38%23%34%26%6%
760
21st to endNight
5%13%24%33%20%6%
836
Page generated at 2024-01-09 22:25:01. Version ac07

Copyright 2024 Attilla Danko


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