Santa Paula
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Santa Paula clear sky chart from 2005-11-05 to 2017-12-04.

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
76%
16100
34%
47801
29%
16055
81%
16055
52%
23276

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
61%
717
29%
2429
26%
716
71%
716
41%
1202
January16th to endNight
57%
768
34%
2445
26%
768
70%
768
39%
1268
February1st to 15thNight
67%
698
36%
2101
32%
696
77%
696
45%
1088
February16th to endNight
62%
632
29%
1895
29%
632
66%
632
36%
1086
March1st to 15thNight
70%
720
28%
2145
27%
720
76%
720
50%
1058
March16th to endNight
73%
768
30%
1995
25%
768
77%
768
50%
1107
April1st to 15thNight
70%
719
31%
1799
20%
719
74%
719
51%
993
April16th to endNight
76%
720
32%
1800
18%
720
79%
720
58%
947
May1st to 15thNight
79%
665
28%
1745
19%
665
80%
665
52%
936
May16th to endNight
82%
561
32%
1685
25%
561
83%
561
58%
782
June1st to 15thNight
86%
375
30%
1455
34%
375
88%
375
47%
617
June16th to endNight
95%
360
36%
1440
45%
360
96%
360
58%
524
July1st to 15thNight
91%
340
33%
1360
39%
340
91%
340
57%
503
July16th to endNight
89%
608
33%
1632
27%
570
90%
570
60%
756
August1st to 15thNight
92%
717
34%
1790
23%
713
92%
713
69%
867
August16th to endNight
95%
764
40%
1910
26%
764
95%
764
69%
929
September1st to 15thNight
90%
720
37%
1800
30%
720
90%
720
63%
926
September16th to endNight
93%
716
42%
1976
41%
716
94%
716
69%
882
October1st to 15thNight
81%
720
35%
2052
35%
720
85%
720
60%
964
October16th to endNight
78%
768
43%
2304
43%
768
84%
768
57%
1060
November1st to 15thNight
76%
760
34%
2455
33%
760
82%
760
55%
1088
November16th to endNight
70%
780
39%
2535
38%
780
77%
780
52%
1152
December1st to 15thNight
65%
736
35%
2392
31%
736
75%
736
43%
1199
December16th to endNight
58%
768
32%
2661
28%
768
69%
768
38%
1342

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
4212212346%68%
48676
Night
4212212246%69%
48002
TransparencyDay
18%37%17%28%23%
48365
Night
18%37%17%26%26%
47813
SeeingDay
5%6%28%39%15%4
6262
Night
5%111%32%36%12%
16112

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
7%213322335%64%
1507
16th to endDay
11%323212235%61%
1778
February1st to 15thDay
8%4232235%6%61%
1751
16th to endDay
10%313323336%56%
1579
March1st to 15thDay
4213223447%61%
1812
16th to endDay
4223313349%59%
2229
April1st to 15thDay
6%323213346%61%
2149
16th to endDay
4312111237%69%
2160
May1st to 15thDay
341222247%66%
2202
16th to endDay
2212212237%70%
2429
June1st to 15thDay
5%413212247%64%
2502
16th to endDay
112245%79%
2520
July1st to 15thDay
1212212346%72%
2520
16th to endDay
2112112336%72%
2420
August1st to 15thDay
112111235%77%
2160
16th to endDay
111222481%
2292
September1st to 15thDay
11111233478%
2160
16th to endDay
1121112480%
1983
October1st to 15thDay
421212235%72%
1905
16th to endDay
321221233471%
1920
November1st to 15thDay
3212212347%68%
1734
16th to endDay
322322336%67%
1755
December1st to 15thDay
6%31312435%9%58%
1649
16th to endDay
9%414312346%59%
1560
January1st to 15thNight
6%223323346%61%
2429
16th to endNight
10%313212335%61%
2445
February1st to 15thNight
6%313212336%64%
2101
16th to endNight
12%31331334457%
1895
March1st to 15thNight
431221225%7%65%
2145
16th to endNight
4312323446%64%
1995
April1st to 15thNight
5%412212236%66%
1799
16th to endNight
231212246%71%
1800
May1st to 15thNight
3412112247%69%
1745
16th to endNight
121212245%74%
1684
June1st to 15thNight
121212337%70%
1455
16th to endNight
11123483%
1440
July1st to 15thNight
1111211245%76%
1440
16th to endNight
12111235%6%72%
1744
August1st to 15thNight
11111235%79%
1800
16th to endNight
1112235%80%
1910
September1st to 15thNight
212112236%75%
1800
16th to endNight
1135%82%
1976
October1st to 15thNight
3112112235%73%
2052
16th to endNight
221211224473%
2304
November1st to 15thNight
2212212235%72%
2455
16th to endNight
322212346%69%
2535
December1st to 15thNight
6%223213246%63%
2392
16th to endNight
11%313112236%61%
2661

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
24%37%14%24%25%
1507
16th to endDay
27%27%17%18%26%
1778
February1st to 15thDay
23%45%16%27%21%
1751
16th to endDay
29%49%18%28%9%
1579
March1st to 15thDay
24%410%19%22%19%
1812
16th to endDay
22%5%12%24%21%13%
2229
April1st to 15thDay
23%6%10%26%23%10%
2149
16th to endDay
17%49%24%29%14%
2160
May1st to 15thDay
21%48%21%26%17%
2202
16th to endDay
15%6%10%29%28%9%
2432
June1st to 15thDay
24%410%15%31%14%
2502
16th to endDay
10%35%9%37%33%
2520
July1st to 15thDay
15%2412%28%35%
2371
16th to endDay
16%36%20%30%23%
2269
August1st to 15thDay
12%25%12%37%29%
2146
16th to endDay
10%2310%43%29%
2292
September1st to 15thDay
11%26%13%29%37%
2160
16th to endDay
11%2313%34%34%
1983
October1st to 15thDay
16%36%19%24%28%
1905
16th to endDay
18%35%13%24%35%
1920
November1st to 15thDay
18%45%15%26%29%
1734
16th to endDay
19%37%15%21%32%
1755
December1st to 15thDay
24%48%17%24%21%
1649
16th to endDay
26%48%19%20%19%
1560
January1st to 15thNight
24%36%14%25%25%
2429
16th to endNight
27%26%14%17%31%
2445
February1st to 15thNight
23%4416%24%26%
2112
16th to endNight
32%45%17%25%14%
1895
March1st to 15thNight
19%39%19%26%19%
2145
16th to endNight
21%5%10%22%23%16%
1995
April1st to 15thNight
22%29%25%26%12%
1799
16th to endNight
16%48%23%29%18%
1800
May1st to 15thNight
19%5%9%22%26%16%
1746
16th to endNight
14%49%28%31%11%
1685
June1st to 15thNight
18%311%18%33%14%
1455
16th to endNight
8%6%413%34%33%
1440
July1st to 15thNight
13%25%13%24%40%
1360
16th to endNight
15%28%24%25%23%
1632
August1st to 15thNight
11%37%12%34%31%
1790
16th to endNight
10%449%42%29%
1910
September1st to 15thNight
15%36%9%27%37%
1800
16th to endNight
8%4411%35%34%
1976
October1st to 15thNight
14%3417%28%30%
2052
16th to endNight
16%25%12%21%40%
2304
November1st to 15thNight
17%27%14%25%32%
2455
16th to endNight
18%35%16%22%34%
2535
December1st to 15thNight
24%37%16%22%26%
2392
16th to endNight
26%38%17%23%19%
2661

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
14%8%47%22%5%
135
16th to endDay
14%11%38%28%5%1
265
February1st to 15thDay
12%7%36%34%5%3
266
16th to endDay
15%13%33%29%6%
238
March1st to 15thDay
6%11%37%30%12%1
270
16th to endDay
7%7%38%32%11%1
288
April1st to 15thDay
9%12%40%23%8%4
269
16th to endDay
5%12%41%29%8%2
270
May1st to 15thDay
7%10%34%33%10%4
288
16th to endDay
49%32%36%14%3
330
June1st to 15thDay
10%7%23%41%14%2
315
16th to endDay
119%48%21%9%
315
July1st to 15thDay
113%49%27%6%
305
16th to endDay
318%48%29%8%
327
August1st to 15thDay
114%56%18%7%
315
16th to endDay
19%53%25%8%
332
September1st to 15thDay
2125%48%15%5%
315
16th to endDay
1425%50%13%4
315
October1st to 15thDay
38%33%38%14%
315
16th to endDay
3433%38%16%3
336
November1st to 15thDay
6%226%38%22%4
150
16th to endDay
5%8%29%32%20%3
135
December1st to 15thDay
5%6%21%44%21%3
100
16th to endDay
414%36%38%41
68
January1st to 15thNight
8%320%42%18%6%
720
16th to endNight
11%5%19%37%21%4
768
February1st to 15thNight
8%314%41%25%5%
704
16th to endNight
13%215%40%23%4
632
March1st to 15thNight
6%216%41%27%5%
720
16th to endNight
5%112%42%32%5%
768
April1st to 15thNight
7%213%40%29%6%
719
16th to endNight
3312%37%34%8%
720
May1st to 15thNight
6%110%37%36%8%
666
16th to endNight
1112%33%42%8%
563
June1st to 15thNight
1431%49%13%
375
16th to endNight
20%65%13%
360
July1st to 15thNight
217%62%26%
340
16th to endNight
128%54%33%
608
August1st to 15thNight
1115%57%23%
717
16th to endNight
19%57%31%
764
September1st to 15thNight
3117%54%21%
720
16th to endNight
1226%49%19%
716
October1st to 15thNight
39%36%41%8%
720
16th to endNight
3112%33%36%13%
768
November1st to 15thNight
414%41%29%10%
760
16th to endNight
5%116%36%30%8%
780
December1st to 15thNight
7%218%41%23%6%
736
16th to endNight
12%320%38%20%4
768
Page generated at 2017-12-05 07:19:02. Version ac04

Copyright 2017 A. Danko


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