Laguna Niguel
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Laguna Niguel clear sky chart from 2005-11-06 to 2024-03-23.

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
73%
24905
29%
79442
28%
24817
75%
24817
38%
43656

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
69%
750
37%
3979
30%
736
73%
736
31%
1570
January11th to 20thNight
69%
749
31%
3822
33%
740
75%
740
26%
1959
January21st to endNight
63%
828
23%
3938
31%
814
70%
814
24%
2188
February1st to 10thNight
68%
760
34%
2280
33%
760
72%
760
42%
1216
February11th to 20thNight
65%
740
31%
2218
30%
740
71%
740
39%
1243
February21st to endNight
61%
628
27%
1884
27%
628
65%
628
34%
1124
March1st to 10thNight
63%
760
25%
2280
26%
760
67%
760
35%
1327
March11th to 20thNight
67%
760
24%
2228
25%
760
69%
760
37%
1302
March21st to endNight
69%
800
28%
2014
21%
800
73%
800
43%
1207
April1st to 10thNight
67%
720
26%
1800
19%
720
69%
720
39%
1133
April11th to 20thNight
67%
711
29%
1779
19%
711
70%
711
45%
1054
April21st to endNight
70%
720
25%
1800
16%
720
72%
720
41%
1118
May1st to 10thNight
68%
648
22%
1728
15%
648
69%
648
35%
1092
May11th to 20thNight
67%
531
20%
1595
17%
531
67%
531
30%
1021
May21st to endNight
67%
582
22%
1746
17%
582
68%
582
33%
1081
June1st to 10thNight
63%
540
16%
1620
14%
540
64%
540
24%
1132
June11th to 20thNight
75%
502
25%
1582
22%
502
75%
502
34%
934
June21st to endNight
75%
360
25%
1440
31%
360
75%
360
28%
789
July1st to 10thNight
76%
350
26%
1400
32%
350
76%
350
30%
739
July11th to 20thNight
84%
509
25%
1553
22%
509
84%
509
42%
846
July21st to endNight
82%
744
26%
1819
19%
703
82%
703
46%
1054
August1st to 10thNight
83%
716
29%
1780
19%
712
83%
712
51%
1006
August11th to 20thNight
86%
712
33%
1780
21%
712
86%
712
53%
992
August21st to endNight
86%
792
34%
1980
24%
792
86%
792
54%
1083
September1st to 10thNight
82%
720
34%
1800
28%
720
82%
720
51%
1019
September11th to 20thNight
85%
720
37%
1957
35%
720
85%
720
54%
994
September21st to endNight
84%
720
38%
1980
38%
720
85%
720
54%
1004
October1st to 10thNight
82%
720
35%
1980
35%
720
83%
720
54%
1005
October11th to 20thNight
77%
720
38%
2040
38%
720
79%
720
49%
1066
October21st to endNight
79%
792
38%
2430
41%
792
81%
792
50%
1175
November1st to 10thNight
78%
740
34%
2405
38%
740
81%
740
48%
1133
November11th to 20thNight
81%
760
37%
2470
41%
760
84%
760
50%
1167
November21st to endNight
71%
760
32%
2470
35%
760
74%
760
40%
1281
December1st to 10thNight
69%
760
31%
2470
31%
760
72%
760
37%
1327
December11th to 20thNight
65%
758
29%
2961
33%
758
69%
758
27%
1759
December21st to endNight
62%
823
20%
4434
30%
817
68%
817
20%
2516

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
5%423323447%62%
79723
Night
7%5%24434447%57%
80240
TransparencyDay
23%48%20%24%21%
79453
Night
30%47%16%21%22%
80032
SeeingDay
6%417%35%30%8%
14923
Night
8%37%30%39%14%
24955

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
7%312223337%66%
2858
11th to 20thDay
8%5%3432446%7%55%
3088
21st to endDay
14%5%25%5%34346%50%
3498
February1st to 10thDay
10%42442345%6%58%
1900
11th to 20thDay
8%324323448%59%
1850
21st to endDay
9%5%2442445%6%54%
1570
March1st to 10thDay
7%5%24435%6%6%9%49%
1900
11th to 20thDay
6%41432446%10%56%
1950
21st to endDay
5%3133245%5%8%60%
2382
April1st to 10thDay
6%42232445%9%57%
2160
11th to 20thDay
4414324446%64%
2129
21st to endDay
5%313313348%65%
2160
May1st to 10thDay
5%42443345%8%57%
2231
11th to 20thDay
442432345%9%60%
2301
21st to endDay
6%6%245%2445%8%56%
2530
June1st to 10thDay
6%6%34424348%57%
2340
11th to 20thDay
35%13223347%67%
2367
21st to endDay
2324423335%70%
2520
July1st to 10thDay
1313333447%68%
2520
11th to 20thDay
1214323447%68%
2350
21st to endDay
221323446%8%66%
2388
August1st to 10thDay
1213313336%74%
2149
11th to 20thDay
1212222246%76%
2122
21st to endDay
1213323346%73%
2376
September1st to 10thDay
3212223346%74%
2160
11th to 20thDay
2212222336%74%
2002
21st to endDay
1213322336%74%
1980
October1st to 10thDay
5%323323247%67%
1980
11th to 20thDay
5%323223336%67%
1917
21st to endDay
3313313446%69%
1926
November1st to 10thDay
4322322446%68%
1674
11th to 20thDay
4212334346%67%
1710
21st to endDay
6%3233235%6%8%60%
1710
December1st to 10thDay
7%5%2343445%9%56%
1710
11th to 20thDay
12%6%35%4345%5%7%45%
2169
21st to endDay
11%7%25%6%5%5%5%5%8%41%
3146
January1st to 10thNight
7%413323336%64%
4097
11th to 20thNight
8%6%25%424447%52%
3884
21st to endNight
13%6%24324446%51%
4180
February1st to 10thNight
8%424423436%59%
2280
11th to 20thNight
9%5%23344335%58%
2218
21st to endNight
12%5%15%5%34346%52%
1884
March1st to 10thNight
9%6%35%5%25%45%9%48%
2280
11th to 20thNight
9%6%25%43445%8%51%
2228
21st to endNight
7%5%245%2445%7%56%
2014
April1st to 10thNight
8%7%3443435%8%50%
1800
11th to 20thNight
7%6%34423246%59%
1779
21st to endNight
7%7%35%42445%6%55%
1800
May1st to 10thNight
6%9%36%434348%50%
1728
11th to 20thNight
5%11%36%6%4345%7%46%
1594
21st to endNight
7%9%37%5%33447%50%
1746
June1st to 10thNight
6%10%5%8%6%45%447%40%
1620
11th to 20thNight
29%25%436%45%8%51%
1582
21st to endNight
36%37%7%345%48%51%
1440
July1st to 10thNight
26%37%6%35%5%6%7%50%
1440
11th to 20thNight
25%25%445%45%7%57%
1606
21st to endNight
25%2443446%8%57%
1926
August1st to 10thNight
3413445%347%62%
1790
11th to 20thNight
1314435%337%65%
1780
21st to endNight
2314344347%64%
1980
September1st to 10thNight
4423334337%64%
1800
11th to 20thNight
341242333472%
1957
21st to endNight
2323323325%71%
1980
October1st to 10thNight
4323333345%68%
1980
11th to 20thNight
5%5%23322335%67%
2040
21st to endNight
4423223346%67%
2430
November1st to 10thNight
4313433336%66%
2405
11th to 20thNight
4323323336%68%
2470
21st to endNight
5%5%2442446%8%55%
2470
December1st to 10thNight
8%42443445%7%55%
2470
11th to 20thNight
12%7%25%43445%6%47%
3041
21st to endNight
12%6%35%5%35%5%5%6%44%
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
20%46%27%25%17%
2859
11th to 20thDay
28%5%16%20%15%16%
3088
21st to endDay
35%45%17%23%16%
3498
February1st to 10thDay
28%46%15%24%24%
1900
11th to 20thDay
24%47%18%27%20%
1860
21st to endDay
29%47%20%24%16%
1570
March1st to 10thDay
28%6%9%19%19%18%
1900
11th to 20thDay
24%5%11%23%23%13%
1950
21st to endDay
23%5%13%25%21%14%
2382
April1st to 10thDay
25%5%12%29%20%10%
2160
11th to 20thDay
22%48%23%25%18%
2132
21st to endDay
20%313%25%27%11%
2160
May1st to 10thDay
26%5%11%23%21%13%
2231
11th to 20thDay
25%48%27%25%11%
2304
21st to endDay
27%5%9%29%24%6%
2530
June1st to 10thDay
29%5%9%20%26%11%
2340
11th to 20thDay
20%46%17%30%23%
2367
21st to endDay
22%1413%25%36%
2520
July1st to 10thDay
20%25%15%23%34%
2451
11th to 20thDay
18%310%19%28%22%
2280
21st to endDay
19%310%26%27%14%
2255
August1st to 10thDay
15%2419%31%29%
2135
11th to 20thDay
13%25%21%32%27%
2122
21st to endDay
15%25%17%32%29%
2376
September1st to 10thDay
15%35%13%35%30%
2160
11th to 20thDay
16%2415%32%30%
2002
21st to endDay
16%2417%33%28%
1980
October1st to 10thDay
20%36%20%23%28%
1980
11th to 20thDay
21%3419%24%29%
1917
21st to endDay
17%46%14%22%37%
1926
November1st to 10thDay
20%35%20%21%31%
1674
11th to 20thDay
19%37%17%19%35%
1710
21st to endDay
22%49%14%24%28%
1710
December1st to 10thDay
26%410%18%19%23%
1710
11th to 20thDay
37%6%10%14%20%14%
2168
21st to endDay
39%7%10%20%14%10%
3146
January1st to 10thNight
21%5%7%16%31%20%
4097
11th to 20thNight
31%6%12%20%14%17%
3884
21st to endNight
35%47%14%20%19%
4180
February1st to 10thNight
27%37%14%23%27%
2280
11th to 20thNight
30%46%15%21%24%
2219
21st to endNight
36%45%14%21%21%
1884
March1st to 10thNight
32%5%9%19%17%18%
2280
11th to 20thNight
33%49%19%20%15%
2228
21st to endNight
29%49%24%21%13%
2014
April1st to 10thNight
35%310%23%18%12%
1800
11th to 20thNight
28%48%20%22%18%
1779
21st to endNight
33%311%20%22%11%
1800
May1st to 10thNight
37%410%19%17%13%
1728
11th to 20thNight
41%39%18%17%11%
1595
21st to endNight
38%39%22%21%8%
1746
June1st to 10thNight
50%38%10%19%10%
1620
11th to 20thNight
35%45%13%26%17%
1582
21st to endNight
36%36%10%18%26%
1440
July1st to 10thNight
35%25%16%16%26%
1400
11th to 20thNight
27%48%17%23%20%
1553
21st to endNight
27%410%23%25%11%
1819
August1st to 10thNight
25%3416%27%24%
1780
11th to 20thNight
24%25%16%27%26%
1780
21st to endNight
22%26%14%26%28%
1980
September1st to 10thNight
24%45%10%28%29%
1800
11th to 20thNight
21%2410%29%34%
1957
21st to endNight
21%2413%32%28%
1980
October1st to 10thNight
21%37%19%23%28%
1980
11th to 20thNight
24%3415%25%29%
2040
21st to endNight
21%3312%23%38%
2430
November1st to 10thNight
21%35%16%20%35%
2405
11th to 20thNight
21%25%16%18%38%
2470
21st to endNight
27%47%17%17%29%
2470
December1st to 10thNight
29%47%15%19%25%
2470
11th to 20thNight
38%48%14%20%16%
3041
21st to endNight
38%6%11%19%14%12%
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
14%6%16%37%23%4
270
11th to 20thDay
12%417%40%23%5%
407
21st to endDay
9%7%23%33%24%4
506
February1st to 10thDay
12%7%20%32%23%7%
460
11th to 20thDay
9%9%26%34%20%2
455
21st to endDay
9%10%29%34%17%2
382
March1st to 10thDay
10%9%31%32%14%4
460
11th to 20thDay
9%7%25%35%21%3
460
21st to endDay
6%8%29%35%19%2
471
April1st to 10thDay
7%5%25%37%20%5%
420
11th to 20thDay
39%30%36%18%5%
412
21st to endDay
46%25%34%23%8%
420
May1st to 10thDay
6%5%25%34%23%6%
423
11th to 20thDay
6%6%18%43%23%6%
448
21st to endDay
8%7%20%38%22%5%
485
June1st to 10thDay
6%314%36%34%6%
450
11th to 20thDay
6%114%35%34%11%
450
21st to endDay
4210%33%41%10%
450
July1st to 10thDay
21431%49%13%
446
11th to 20thDay
3224%51%20%
444
21st to endDay
2231%46%19%
487
August1st to 10thDay
415%34%42%15%
447
11th to 20thDay
3429%46%17%
437
21st to endDay
3235%44%16%
495
September1st to 10thDay
316%43%35%12%
450
11th to 20thDay
2214%41%32%8%
450
21st to endDay
2116%38%32%11%
450
October1st to 10thDay
4317%39%31%7%
450
11th to 20thDay
6%216%38%29%9%
450
21st to endDay
5%415%35%30%11%
441
November1st to 10thDay
36%14%32%35%10%
270
11th to 20thDay
4214%40%30%10%
270
21st to endDay
5%5%19%37%25%9%
270
December1st to 10thDay
9%5%13%38%29%5%
270
11th to 20thDay
7%416%36%27%10%
270
21st to endDay
12%8%21%34%20%4
297
January1st to 10thNight
11%211%38%27%11%
760
11th to 20thNight
9%211%36%32%10%
760
21st to endNight
12%413%36%30%6%
836
February1st to 10thNight
11%310%35%30%11%
760
11th to 20thNight
10%313%38%28%8%
744
21st to endNight
12%412%40%26%5%
628
March1st to 10thNight
10%313%43%24%6%
760
11th to 20thNight
10%5%11%34%31%10%
760
21st to endNight
9%310%37%36%6%
800
April1st to 10thNight
12%37%38%34%6%
720
11th to 20thNight
8%411%36%32%9%
711
21st to endNight
9%48%31%39%9%
720
May1st to 10thNight
11%48%33%36%8%
648
11th to 20thNight
11%38%29%40%9%
531
21st to endNight
10%49%31%39%8%
584
June1st to 10thNight
14%39%30%36%8%
540
11th to 20thNight
8%25%27%49%9%
502
21st to endNight
12%1118%54%13%
360
July1st to 10thNight
9%137%52%27%
350
11th to 20thNight
5%28%55%29%
509
21st to endNight
5%128%54%30%
744
August1st to 10thNight
5%2213%54%25%
716
11th to 20thNight
5%118%52%33%
712
21st to endNight
5%1110%54%30%
792
September1st to 10thNight
7%1313%51%26%
720
11th to 20thNight
5%2219%55%17%
720
21st to endNight
41427%48%18%
720
October1st to 10thNight
5%2435%44%11%
720
11th to 20thNight
8%15%30%40%16%
720
21st to endNight
7%16%29%39%17%
792
November1st to 10thNight
5%27%32%39%15%
740
11th to 20thNight
415%36%39%15%
760
21st to endNight
6%39%39%32%11%
760
December1st to 10thNight
11%28%40%31%9%
760
11th to 20thNight
13%49%38%30%7%
760
21st to endNight
11%6%13%35%26%8%
836
Page generated at 2024-03-19 20:31:09. Version ac07

Copyright © 2024 Attilla Danko.


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