Mount Pinos
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mount Pinos clear sky chart from 2005-11-06 to 2024-01-16.

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
66%
24176
34%
74579
28%
24123
73%
24123
50%
35779

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
48%
756
26%
2641
21%
756
58%
756
32%
1377
January11th to 20thNight
49%
740
32%
2405
23%
740
64%
740
41%
1203
January21st to endNight
43%
792
33%
2529
22%
792
59%
792
32%
1396
February1st to 10thNight
48%
720
31%
2160
24%
720
58%
720
38%
1164
February11th to 20thNight
51%
700
32%
2098
24%
700
64%
700
42%
1080
February21st to endNight
48%
592
29%
1776
24%
592
58%
592
37%
974
March1st to 10thNight
47%
720
23%
2160
18%
720
56%
720
32%
1256
March11th to 20thNight
52%
720
24%
2048
20%
720
58%
720
38%
1157
March21st to endNight
53%
792
27%
2007
16%
792
60%
792
44%
1128
April1st to 10thNight
50%
720
29%
1800
14%
720
58%
720
46%
1019
April11th to 20thNight
55%
711
35%
1779
16%
711
64%
711
55%
926
April21st to endNight
58%
720
33%
1800
15%
720
65%
720
61%
911
May1st to 10thNight
63%
716
31%
1796
16%
716
68%
716
62%
905
May11th to 20thNight
68%
531
38%
1595
27%
531
73%
531
60%
697
May21st to endNight
63%
560
32%
1724
21%
560
70%
560
59%
731
June1st to 10thNight
77%
360
37%
1440
40%
360
83%
360
60%
506
June11th to 20thNight
86%
360
42%
1440
46%
360
92%
360
79%
428
June21st to endNight
88%
360
44%
1440
50%
360
93%
360
83%
412
July1st to 10thNight
94%
350
38%
1400
46%
350
95%
350
73%
436
July11th to 20thNight
92%
377
41%
1421
45%
377
92%
377
70%
486
July21st to endNight
91%
658
39%
1738
31%
622
92%
622
73%
751
August1st to 10thNight
90%
716
38%
1780
25%
712
90%
712
79%
812
August11th to 20thNight
95%
712
42%
1780
25%
712
96%
712
84%
782
August21st to endNight
93%
792
46%
1980
31%
792
94%
792
82%
881
September1st to 10thNight
89%
720
46%
1800
35%
720
90%
720
81%
807
September11th to 20thNight
90%
720
49%
1878
41%
720
93%
720
84%
798
September21st to endNight
84%
720
46%
1980
41%
720
90%
720
80%
819
October1st to 10thNight
77%
720
38%
2011
35%
720
83%
720
66%
908
October11th to 20thNight
71%
720
41%
2160
37%
720
80%
720
61%
934
October21st to endNight
69%
792
43%
2376
37%
792
80%
792
63%
1015
November1st to 10thNight
67%
740
36%
2390
35%
740
74%
740
52%
1062
November11th to 20thNight
64%
760
35%
2470
31%
760
75%
760
51%
1109
November21st to endNight
55%
760
33%
2470
28%
760
65%
760
42%
1227
December1st to 10thNight
53%
760
31%
2470
26%
760
63%
760
38%
1279
December11th to 20thNight
51%
760
25%
3120
26%
759
59%
759
22%
1919
December21st to endNight
47%
829
18%
4717
24%
817
57%
817
19%
2484

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
3423323446%66%
74816
Night
3424424446%64%
74988
TransparencyDay
18%36%17%29%28%
74536
Night
19%46%17%29%26%
74790
SeeingDay
8%11%27%33%16%5%
14386
Night
6%6%18%34%30%7%
24193

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
46%35%6%46%46%9%49%
1521
11th to 20thDay
5%5%25%5%34448%56%
1666
21st to endDay
5%8%48%6%2345%6%49%
1823
February1st to 10thDay
47%35%435%446%56%
1800
11th to 20thDay
46%45%5%3445%8%53%
1750
21st to endDay
46%36%6%34446%54%
1480
March1st to 10thDay
5%8%35%7%46%6%6%8%42%
1800
11th to 20thDay
37%35%5%346%5%9%50%
1909
21st to endDay
46%245%35%6%6%7%53%
2348
April1st to 10thDay
5%7%245%245%5%8%54%
2160
11th to 20thDay
3324423447%64%
2129
21st to endDay
331332345%8%65%
2160
May1st to 10thDay
4313223447%66%
2164
11th to 20thDay
231232345%7%68%
2301
21st to endDay
4413323446%67%
2547
June1st to 10thDay
1212223448%71%
2520
11th to 20thDay
1111123485%
2520
21st to endDay
111112235%84%
2520
July1st to 10thDay
1111212335%80%
2520
11th to 20thDay
2112222347%73%
2486
21st to endDay
2212213447%73%
2474
August1st to 10thDay
2112212345%78%
2149
11th to 20thDay
11112245%83%
2122
21st to endDay
1112112245%81%
2376
September1st to 10thDay
1111212335%81%
2160
11th to 20thDay
1121222485%
2080
21st to endDay
111121233480%
1980
October1st to 10thDay
2312224435%72%
1944
11th to 20thDay
1212223335%76%
1800
21st to endDay
1113323436%73%
1980
November1st to 10thDay
241442345%7%66%
1688
11th to 20thDay
24233245%6%6%65%
1710
21st to endDay
35%35%5%34347%57%
1710
December1st to 10thDay
3425%5%35%6%5%6%55%
1710
11th to 20thDay
5%7%35%7%45%6%7%8%42%
2015
21st to endDay
5%9%46%6%46%6%5%6%41%
2794
January1st to 10thNight
45%36%6%35%5%6%9%47%
2641
11th to 20thNight
3435%5%345%6%6%57%
2405
21st to endNight
48%35%6%3445%6%51%
2529
February1st to 10thNight
37%36%5%3445%7%54%
2160
11th to 20thNight
46%2443445%7%56%
2098
21st to endNight
37%36%6%35%5%5%6%52%
1776
March1st to 10thNight
38%37%5%37%6%7%9%41%
2160
11th to 20thNight
38%36%6%35%5%48%48%
2048
21st to endNight
46%35%5%36%5%5%7%53%
2007
April1st to 10thNight
36%35%6%35%46%7%52%
1800
11th to 20thNight
35%23414347%62%
1779
21st to endNight
3423413447%65%
1800
May1st to 10thNight
3312323446%67%
1796
11th to 20thNight
3323312235%73%
1594
21st to endNight
2313322335%73%
1724
June1st to 10thNight
121222335%5%74%
1440
11th to 20thNight
1111113487%
1440
21st to endNight
111112389%
1440
July1st to 10thNight
11111233483%
1440
11th to 20thNight
22211223382%
1469
21st to endNight
111122223480%
1840
August1st to 10thNight
211111224482%
1790
11th to 20thNight
111122387%
1780
21st to endNight
11111112386%
1980
September1st to 10thNight
111111122387%
1800
11th to 20thNight
111123486%
1878
21st to endNight
11122223482%
1980
October1st to 10thNight
1212224335%74%
2011
11th to 20thNight
221322345%6%71%
2160
21st to endNight
1213323345%74%
2376
November1st to 10thNight
24244235%6%7%62%
2390
11th to 20thNight
332432445%7%63%
2470
21st to endNight
35%245%345%6%8%55%
2470
December1st to 10thNight
36%25%4345%5%8%55%
2470
11th to 20thNight
5%7%36%7%46%8%7%8%39%
3185
21st to endNight
5%7%37%7%46%6%6%8%40%
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
30%46%18%28%14%
1521
11th to 20thDay
26%39%17%27%19%
1666
21st to endDay
33%39%16%22%18%
1823
February1st to 10thDay
27%35%19%26%21%
1800
11th to 20thDay
25%46%20%27%17%
1760
21st to endDay
28%5%6%20%27%13%
1480
March1st to 10thDay
32%7%10%18%20%13%
1800
11th to 20thDay
27%6%9%21%23%14%
1909
21st to endDay
25%5%12%28%21%10%
2348
April1st to 10thDay
24%5%10%24%24%12%
2160
11th to 20thDay
19%49%24%30%14%
2132
21st to endDay
14%5%9%27%34%10%
2160
May1st to 10thDay
17%48%22%36%14%
2164
11th to 20thDay
15%38%23%35%16%
2304
21st to endDay
18%37%26%34%12%
2547
June1st to 10thDay
13%36%20%32%25%
2520
11th to 20thDay
5%25%15%32%41%
2520
21st to endDay
6%237%29%54%
2520
July1st to 10thDay
8%137%23%58%
2451
11th to 20thDay
12%3414%29%38%
2411
21st to endDay
11%36%17%32%31%
2337
August1st to 10thDay
10%337%25%52%
2135
11th to 20thDay
6%1310%32%48%
2122
21st to endDay
10%237%35%45%
2376
September1st to 10thDay
7%248%30%49%
2160
11th to 20thDay
6%2310%36%44%
2080
21st to endDay
9%2211%41%35%
1980
October1st to 10thDay
15%35%16%26%36%
1944
11th to 20thDay
11%25%13%34%35%
1800
21st to endDay
12%35%12%31%37%
1980
November1st to 10thDay
16%3420%32%26%
1688
11th to 20thDay
17%37%17%28%27%
1710
21st to endDay
25%47%14%24%26%
1710
December1st to 10thDay
26%5%6%17%26%20%
1710
11th to 20thDay
36%6%8%19%18%12%
2014
21st to endDay
37%5%6%17%22%12%
2794
January1st to 10thNight
28%47%19%27%15%
2641
11th to 20thNight
22%5%9%17%29%19%
2405
21st to endNight
31%46%16%20%23%
2529
February1st to 10thNight
26%5%6%16%24%23%
2160
11th to 20thNight
24%37%18%29%19%
2099
21st to endNight
27%6%7%19%26%15%
1776
March1st to 10thNight
31%6%8%21%21%13%
2160
11th to 20thNight
27%5%10%20%23%15%
2048
21st to endNight
23%5%13%24%27%8%
2007
April1st to 10thNight
25%312%25%22%13%
1800
11th to 20thNight
17%310%23%31%16%
1779
21st to endNight
13%410%28%36%10%
1800
May1st to 10thNight
14%310%23%37%12%
1796
11th to 20thNight
13%26%26%37%16%
1595
21st to endNight
13%310%29%36%11%
1724
June1st to 10thNight
11%29%22%34%22%
1440
11th to 20thNight
5%15%16%32%41%
1440
21st to endNight
4128%29%56%
1440
July1st to 10thNight
7%236%24%58%
1400
11th to 20thNight
8%2416%30%40%
1421
21st to endNight
8%35%19%31%34%
1738
August1st to 10thNight
7%329%28%51%
1780
11th to 20thNight
5%229%34%48%
1780
21st to endNight
6%118%37%47%
1980
September1st to 10thNight
6%229%29%52%
1800
11th to 20thNight
42311%38%42%
1878
21st to endNight
6%2214%39%38%
1980
October1st to 10thNight
12%2417%28%36%
2011
11th to 20thNight
13%3415%30%36%
2160
21st to endNight
11%36%10%34%37%
2376
November1st to 10thNight
16%35%17%32%26%
2390
11th to 20thNight
17%47%14%28%31%
2470
21st to endNight
23%47%15%24%27%
2470
December1st to 10thNight
25%5%6%14%26%23%
2470
11th to 20thNight
40%5%8%15%19%14%
3185
21st to endNight
33%7%5%18%23%13%
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
19%19%30%22%8%1
182
11th to 20thDay
19%17%31%25%7%1
356
21st to endDay
18%21%31%18%9%2
393
February1st to 10thDay
12%16%35%25%8%3
420
11th to 20thDay
20%18%31%22%8%1
415
21st to endDay
17%19%34%23%6%1
346
March1st to 10thDay
15%22%33%23%5%1
420
11th to 20thDay
16%20%30%25%7%1
420
21st to endDay
15%21%34%24%7%
462
April1st to 10thDay
15%13%34%25%12%1
420
11th to 20thDay
14%17%32%26%10%1
412
21st to endDay
8%15%30%28%14%5%
420
May1st to 10thDay
12%14%32%27%13%3
423
11th to 20thDay
8%12%31%31%13%5%
448
21st to endDay
11%10%27%33%14%6%
485
June1st to 10thDay
5%8%26%33%21%7%
450
11th to 20thDay
26%25%39%21%8%
450
21st to endDay
26%26%37%19%10%
450
July1st to 10thDay
2115%45%25%12%
446
11th to 20thDay
3110%43%27%16%
444
21st to endDay
2112%43%28%15%
487
August1st to 10thDay
2120%43%21%13%
447
11th to 20thDay
2214%43%31%9%
437
21st to endDay
1115%49%23%10%
495
September1st to 10thDay
2323%44%22%6%
450
11th to 20thDay
6%30%45%17%2
450
21st to endDay
18%27%42%17%4
450
October1st to 10thDay
49%32%36%17%2
450
11th to 20thDay
49%36%35%14%3
450
21st to endDay
5%11%31%36%14%3
495
November1st to 10thDay
7%11%29%31%19%3
284
11th to 20thDay
8%11%29%34%15%4
270
21st to endDay
10%14%32%27%13%3
270
December1st to 10thDay
8%13%34%30%13%1
270
11th to 20thDay
12%17%24%28%15%4
221
21st to endDay
18%25%24%21%10%3
198
January1st to 10thNight
12%9%24%30%17%7%
760
11th to 20thNight
8%8%29%34%16%5%
740
21st to endNight
12%12%28%29%14%5%
792
February1st to 10thNight
10%9%25%32%18%6%
720
11th to 20thNight
10%9%26%30%16%9%
704
21st to endNight
10%13%24%34%16%4
592
March1st to 10thNight
9%13%24%34%18%2
720
11th to 20thNight
8%9%23%33%23%5%
720
21st to endNight
8%12%21%35%21%3
792
April1st to 10thNight
7%9%27%35%18%4
720
11th to 20thNight
7%8%24%34%24%3
711
21st to endNight
5%8%25%31%23%7%
720
May1st to 10thNight
5%6%23%35%27%5%
716
11th to 20thNight
5%7%16%35%34%4
531
21st to endNight
5%6%21%32%32%5%
562
June1st to 10thNight
3413%39%36%6%
360
11th to 20thNight
111%43%38%7%
360
21st to endNight
118%41%43%7%
360
July1st to 10thNight
1130%58%11%
350
11th to 20thNight
2127%56%14%
377
21st to endNight
2222%55%18%
658
August1st to 10thNight
2431%52%10%
716
11th to 20thNight
227%57%13%
712
21st to endNight
2128%55%14%
792
September1st to 10thNight
126%28%50%14%
720
11th to 20thNight
17%44%38%10%
720
21st to endNight
1212%36%41%9%
720
October1st to 10thNight
2215%44%32%5%
720
11th to 20thNight
3418%37%30%9%
720
21st to endNight
36%19%32%30%10%
792
November1st to 10thNight
39%17%38%24%9%
740
11th to 20thNight
5%421%38%24%8%
760
21st to endNight
6%8%26%31%23%6%
760
December1st to 10thNight
8%9%25%33%21%4
760
11th to 20thNight
12%10%20%38%15%5%
760
21st to endNight
12%11%23%33%15%6%
836
Page generated at 2024-01-12 22:38:10. Version ac07

Copyright 2024 Attilla Danko


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