Huntington Beach
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Huntington Beach clear sky chart from 2005-11-06 to 2024-02-25.

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
69%
24676
29%
79246
27%
24598
72%
24598
38%
42912

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
67%
744
35%
4190
29%
736
72%
736
31%
1576
January11th to 20thNight
68%
746
32%
3832
32%
740
75%
740
27%
1908
January21st to endNight
60%
826
24%
3949
28%
814
70%
814
24%
2211
February1st to 10thNight
63%
760
34%
2280
31%
760
70%
760
39%
1248
February11th to 20thNight
64%
740
32%
2218
29%
740
72%
740
39%
1205
February21st to endNight
60%
610
28%
1829
28%
610
66%
610
36%
1036
March1st to 10thNight
61%
720
26%
2160
26%
720
67%
720
37%
1223
March11th to 20thNight
62%
720
23%
2114
23%
720
66%
720
35%
1237
March21st to endNight
66%
792
30%
1980
21%
792
71%
792
46%
1152
April1st to 10thNight
65%
720
26%
1800
18%
720
67%
720
41%
1101
April11th to 20thNight
64%
711
31%
1779
18%
711
68%
711
47%
1022
April21st to endNight
64%
720
26%
1800
15%
720
66%
720
40%
1106
May1st to 10thNight
63%
666
23%
1746
15%
666
64%
666
40%
1058
May11th to 20thNight
63%
531
23%
1595
18%
531
64%
531
35%
958
May21st to endNight
63%
582
25%
1746
19%
582
65%
582
41%
982
June1st to 10thNight
59%
540
19%
1620
16%
540
60%
540
30%
1060
June11th to 20thNight
70%
420
26%
1500
27%
420
70%
420
35%
784
June21st to endNight
66%
360
24%
1440
29%
360
66%
360
24%
833
July1st to 10thNight
72%
350
29%
1400
34%
350
72%
350
33%
693
July11th to 20thNight
79%
437
28%
1481
28%
437
79%
437
41%
768
July21st to endNight
74%
767
23%
1841
16%
725
75%
725
42%
1102
August1st to 10thNight
78%
716
29%
1780
18%
712
78%
712
51%
1007
August11th to 20thNight
77%
712
32%
1780
21%
712
77%
712
48%
1021
August21st to endNight
79%
792
32%
1980
22%
792
79%
792
50%
1132
September1st to 10thNight
76%
720
32%
1800
26%
720
76%
720
48%
1055
September11th to 20thNight
81%
720
37%
1941
35%
720
82%
720
53%
1006
September21st to endNight
78%
720
37%
1980
37%
720
80%
720
54%
1009
October1st to 10thNight
77%
720
34%
1980
34%
720
79%
720
51%
1035
October11th to 20thNight
72%
720
36%
2070
36%
720
75%
720
47%
1083
October21st to endNight
78%
792
39%
2412
41%
792
81%
792
52%
1158
November1st to 10thNight
75%
740
33%
2405
35%
740
79%
740
46%
1149
November11th to 20thNight
78%
760
37%
2470
40%
760
82%
760
50%
1141
November21st to endNight
68%
760
32%
2470
34%
760
71%
760
39%
1281
December1st to 10thNight
66%
760
30%
2470
30%
760
70%
760
37%
1320
December11th to 20thNight
60%
759
29%
2963
31%
759
67%
759
26%
1758
December21st to endNight
62%
823
20%
4445
30%
817
69%
817
21%
2494

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%42332345%8%60%
79277
Night
7%7%2442445%7%54%
80025
TransparencyDay
22%47%20%25%21%
79004
Night
28%5%7%17%22%21%
79820
SeeingDay
7%7%23%37%20%7%
14756
Night
8%38%33%36%12%
24736

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
6%422223348%65%
2595
11th to 20thDay
9%5%3433345%9%52%
3050
21st to endDay
12%6%25%424447%50%
3498
February1st to 10thDay
9%423324347%58%
1900
11th to 20thDay
7%42432335%9%59%
1850
21st to endDay
7%5%1333446%7%57%
1521
March1st to 10thDay
7%3244346%7%8%53%
1800
11th to 20thDay
6%42442427%10%54%
1839
21st to endDay
5%42242445%7%61%
2376
April1st to 10thDay
5%5%1332445%9%59%
2160
11th to 20thDay
3313324346%66%
2129
21st to endDay
3423323448%64%
2160
May1st to 10thDay
5%323424449%59%
2212
11th to 20thDay
46%24323347%61%
2301
21st to endDay
6%5%24423348%60%
2530
June1st to 10thDay
7%7%2432345%9%53%
2340
11th to 20thDay
4423323248%64%
2452
21st to endDay
36%23324348%62%
2520
July1st to 10thDay
35%2332335%9%60%
2520
11th to 20thDay
242332345%9%63%
2426
21st to endDay
231332445%8%64%
2366
August1st to 10thDay
2323312347%70%
2149
11th to 20thDay
2312222248%70%
2122
21st to endDay
2312323448%68%
2376
September1st to 10thDay
231322345%7%69%
2160
11th to 20thDay
241322235%8%67%
2017
21st to endDay
1313222347%71%
1980
October1st to 10thDay
431332335%7%66%
1980
11th to 20thDay
5%423222345%68%
1886
21st to endDay
431332245%7%67%
1943
November1st to 10thDay
3324423348%65%
1674
11th to 20thDay
431332345%6%66%
1710
21st to endDay
5%31442345%8%61%
1710
December1st to 10thDay
6%6%25%42445%8%54%
1710
11th to 20thDay
11%5%35%5%35%46%8%46%
2169
21st to endDay
10%8%36%7%445%6%7%39%
3146
January1st to 10thNight
6%423322346%64%
4320
11th to 20thNight
8%7%24434448%52%
3890
21st to endNight
12%7%344245%46%50%
4180
February1st to 10thNight
8%6%35%423336%58%
2280
11th to 20thNight
8%5%24324346%59%
2218
21st to endNight
10%5%24434445%54%
1829
March1st to 10thNight
7%7%25%434448%52%
2160
11th to 20thNight
8%8%3442445%9%48%
2114
21st to endNight
6%5%2333445%9%54%
1980
April1st to 10thNight
9%7%35%42335%9%52%
1800
11th to 20thNight
6%7%24313246%61%
1779
21st to endNight
7%9%35%32345%6%52%
1800
May1st to 10thNight
7%9%35%433449%49%
1746
11th to 20thNight
7%12%44425%347%47%
1594
21st to endNight
7%9%25%423248%53%
1746
June1st to 10thNight
9%15%46%5%3445%6%39%
1620
11th to 20thNight
6%10%3443445%9%48%
1500
21st to endNight
7%13%5%6%4345%5%8%41%
1440
July1st to 10thNight
410%46%4245%5%11%44%
1440
11th to 20thNight
36%36%4346%7%9%49%
1530
21st to endNight
49%25%5%3446%9%48%
1949
August1st to 10thNight
37%3343445%9%56%
1790
11th to 20thNight
49%2442435%9%54%
1780
21st to endNight
27%245%35%5%5%9%54%
1980
September1st to 10thNight
5%6%25%43445%7%56%
1800
11th to 20thNight
4423423349%62%
1941
21st to endNight
37%33213346%65%
1980
October1st to 10thNight
4414433447%63%
1980
11th to 20thNight
5%6%24322336%63%
2070
21st to endNight
4413323347%66%
2412
November1st to 10thNight
35%2342435%7%62%
2405
11th to 20thNight
35%23313346%66%
2470
21st to endNight
46%2443445%8%55%
2470
December1st to 10thNight
7%6%25%5%24348%54%
2470
11th to 20thNight
12%8%36%5%24447%46%
3041
21st to endNight
11%6%36%5%345%6%7%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
19%36%28%26%17%
2595
11th to 20thDay
30%417%18%16%16%
3050
21st to endDay
34%45%20%20%16%
3498
February1st to 10thDay
27%46%15%24%24%
1900
11th to 20thDay
23%47%19%24%23%
1860
21st to endDay
26%47%22%22%18%
1521
March1st to 10thDay
28%410%20%17%21%
1800
11th to 20thDay
25%312%23%23%15%
1839
21st to endDay
23%5%12%25%21%14%
2376
April1st to 10thDay
23%413%29%20%11%
2160
11th to 20thDay
19%48%25%26%17%
2132
21st to endDay
19%410%27%27%12%
2160
May1st to 10thDay
23%5%11%25%25%12%
2212
11th to 20thDay
23%48%26%28%10%
2304
21st to endDay
25%310%31%25%6%
2530
June1st to 10thDay
27%5%9%21%27%11%
2340
11th to 20thDay
20%45%15%34%23%
2452
21st to endDay
20%5%211%28%34%
2520
July1st to 10thDay
18%5%410%27%35%
2451
11th to 20thDay
17%5%7%19%30%22%
2352
21st to endDay
16%5%9%25%31%14%
2235
August1st to 10thDay
15%3216%32%32%
2135
11th to 20thDay
12%4217%36%29%
2122
21st to endDay
14%4314%36%29%
2376
September1st to 10thDay
14%5%312%35%32%
2160
11th to 20thDay
16%4215%33%31%
2017
21st to endDay
14%3319%34%28%
1980
October1st to 10thDay
19%46%21%24%27%
1980
11th to 20thDay
20%3418%26%30%
1886
21st to endDay
17%46%15%20%38%
1943
November1st to 10thDay
18%45%19%22%31%
1674
11th to 20thDay
18%39%16%19%36%
1710
21st to endDay
22%47%16%22%29%
1710
December1st to 10thDay
28%47%18%19%23%
1710
11th to 20thDay
36%5%10%17%17%16%
2168
21st to endDay
40%7%10%18%14%11%
3146
January1st to 10thNight
22%38%17%31%19%
4320
11th to 20thNight
30%5%14%20%15%16%
3890
21st to endNight
34%6%7%17%19%18%
4180
February1st to 10thNight
30%25%15%22%26%
2280
11th to 20thNight
28%46%17%21%24%
2219
21st to endNight
32%36%16%22%21%
1829
March1st to 10thNight
32%38%21%18%18%
2160
11th to 20thNight
32%5%9%17%22%15%
2114
21st to endNight
26%5%11%25%21%13%
1980
April1st to 10thNight
30%5%11%24%18%12%
1800
11th to 20thNight
24%5%8%23%22%17%
1779
21st to endNight
30%6%10%21%23%10%
1800
May1st to 10thNight
29%7%11%22%20%11%
1746
11th to 20thNight
34%5%9%24%19%10%
1595
21st to endNight
28%5%12%27%22%7%
1746
June1st to 10thNight
39%7%9%15%20%10%
1620
11th to 20thNight
26%7%6%15%28%17%
1500
21st to endNight
37%7%38%22%23%
1440
July1st to 10thNight
26%7%313%22%29%
1400
11th to 20thNight
24%7%7%18%25%20%
1481
21st to endNight
27%8%10%21%24%11%
1841
August1st to 10thNight
22%6%414%30%24%
1780
11th to 20thNight
24%6%314%31%23%
1780
21st to endNight
21%7%313%29%26%
1980
September1st to 10thNight
25%5%48%30%28%
1800
11th to 20thNight
19%5%312%29%31%
1941
21st to endNight
20%4313%34%26%
1980
October1st to 10thNight
19%6%5%17%25%28%
1980
11th to 20thNight
23%45%15%24%29%
2070
21st to endNight
19%3313%22%38%
2412
November1st to 10thNight
20%5%5%16%21%32%
2405
11th to 20thNight
19%36%16%19%37%
2470
21st to endNight
27%47%16%18%28%
2470
December1st to 10thNight
29%47%15%20%25%
2470
11th to 20thNight
38%47%16%20%15%
3041
21st to endNight
36%7%12%20%13%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
12%7%18%39%19%5%
195
11th to 20thDay
13%5%23%36%19%4
406
21st to endDay
10%9%27%33%17%3
506
February1st to 10thDay
13%7%28%28%18%6%
460
11th to 20thDay
11%11%31%30%14%3
455
21st to endDay
10%12%33%32%12%2
363
March1st to 10thDay
12%11%34%29%11%2
420
11th to 20thDay
11%10%30%30%16%3
420
21st to endDay
10%13%34%29%12%2
462
April1st to 10thDay
8%11%30%32%15%4
420
11th to 20thDay
5%15%36%30%9%4
412
21st to endDay
5%12%29%36%12%6%
420
May1st to 10thDay
5%12%30%34%13%6%
423
11th to 20thDay
5%9%30%37%13%6%
448
21st to endDay
8%13%28%33%14%4
485
June1st to 10thDay
7%5%24%37%22%4
450
11th to 20thDay
5%423%38%22%8%
450
21st to endDay
5%418%43%21%9%
450
July1st to 10thDay
211%50%26%10%
446
11th to 20thDay
316%44%30%16%
444
21st to endDay
1111%44%27%17%
487
August1st to 10thDay
3212%47%24%11%
447
11th to 20thDay
319%49%26%12%
437
21st to endDay
3212%43%29%11%
495
September1st to 10thDay
5%121%41%24%9%
450
11th to 20thDay
4324%40%22%8%
450
21st to endDay
35%21%39%23%8%
450
October1st to 10thDay
5%8%24%37%22%5%
450
11th to 20thDay
6%425%38%21%6%
450
21st to endDay
6%6%22%32%25%9%
458
November1st to 10thDay
7%6%14%35%27%10%
270
11th to 20thDay
6%5%17%34%29%9%
270
21st to endDay
5%6%20%35%25%9%
270
December1st to 10thDay
9%5%17%36%27%6%
270
11th to 20thDay
7%6%19%32%26%10%
270
21st to endDay
17%5%21%35%18%5%
297
January1st to 10thNight
11%311%42%28%6%
760
11th to 20thNight
8%312%41%31%6%
760
21st to endNight
11%316%38%27%5%
836
February1st to 10thNight
10%411%37%31%6%
760
11th to 20thNight
9%5%12%40%28%6%
744
21st to endNight
13%412%42%24%5%
610
March1st to 10thNight
12%312%44%24%5%
720
11th to 20thNight
11%311%38%28%8%
720
21st to endNight
8%412%39%32%5%
792
April1st to 10thNight
10%5%9%40%29%6%
720
11th to 20thNight
9%412%37%32%6%
711
21st to endNight
9%5%9%35%33%8%
720
May1st to 10thNight
9%412%36%33%7%
666
11th to 20thNight
9%411%33%35%9%
531
21st to endNight
7%412%35%34%8%
584
June1st to 10thNight
9%39%35%36%8%
540
11th to 20thNight
7%25%26%45%14%
420
21st to endNight
10%3123%48%16%
360
July1st to 10thNight
5%36%60%25%
350
11th to 20thNight
3214%49%31%
437
21st to endNight
7%2116%45%28%
767
August1st to 10thNight
5%3220%45%25%
716
11th to 20thNight
9%113%45%31%
712
21st to endNight
5%2115%49%29%
792
September1st to 10thNight
7%1220%48%22%
720
11th to 20thNight
6%2123%53%15%
720
21st to endNight
5%3325%49%15%
720
October1st to 10thNight
6%15%33%47%8%
720
11th to 20thNight
9%16%31%41%12%
720
21st to endNight
6%26%34%37%15%
792
November1st to 10thNight
6%46%33%39%11%
740
11th to 20thNight
425%37%38%13%
760
21st to endNight
8%310%42%31%7%
760
December1st to 10thNight
10%39%43%30%6%
760
11th to 20thNight
15%310%40%27%5%
760
21st to endNight
11%5%13%41%23%7%
836
Page generated at 2024-02-22 03:05:45. Version ac07

Copyright 2024 Attilla Danko


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