El Cariso
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the El Cariso clear sky chart from 2005-11-05 to 2017-09-16.

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
79%
16070
33%
46775
31%
16024
81%
16024
50%
23801

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
71%
719
30%
2316
31%
716
75%
716
42%
1187
January16th to endNight
67%
768
33%
2304
32%
768
71%
768
39%
1276
February1st to 15thNight
72%
697
34%
2104
34%
697
75%
697
45%
1098
February16th to endNight
64%
632
29%
1895
32%
632
66%
632
33%
1137
March1st to 15thNight
76%
720
30%
2160
34%
720
78%
720
44%
1136
March16th to endNight
77%
768
28%
2024
25%
768
78%
768
47%
1139
April1st to 15thNight
70%
719
27%
1799
19%
719
71%
719
44%
1080
April16th to endNight
78%
720
31%
1800
20%
720
79%
720
53%
987
May1st to 15thNight
79%
593
30%
1673
22%
593
79%
593
48%
911
May16th to endNight
79%
561
27%
1685
22%
561
80%
561
45%
910
June1st to 15thNight
85%
540
29%
1620
26%
540
85%
540
53%
805
June16th to endNight
95%
437
39%
1517
41%
437
95%
437
72%
551
July1st to 15thNight
91%
423
32%
1443
32%
423
91%
423
60%
586
July16th to endNight
90%
640
30%
1663
23%
601
90%
601
57%
824
August1st to 15thNight
93%
717
35%
1790
23%
713
93%
713
72%
854
August16th to endNight
94%
764
42%
1910
29%
764
94%
764
75%
891
September1st to 15thNight
90%
720
38%
1854
31%
720
90%
720
66%
900
September16th to endNight
89%
660
44%
1826
43%
660
90%
660
70%
804
October1st to 15thNight
83%
660
38%
1815
37%
660
83%
660
57%
904
October16th to endNight
79%
704
38%
2126
40%
704
81%
704
49%
1049
November1st to 15thNight
83%
700
36%
2275
40%
700
85%
700
53%
1026
November16th to endNight
74%
720
35%
2340
38%
720
77%
720
45%
1151
December1st to 15thNight
70%
720
32%
2340
34%
720
73%
720
37%
1243
December16th to endNight
62%
768
32%
2496
31%
768
68%
768
36%
1352

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
4212213346%66%
47951
Night
4313313346%64%
46982
TransparencyDay
19%26%16%27%27%
47651
Night
21%36%15%25%27%
46784
SeeingDay
46%18%37%24%8%
5933
Night
5%16%31%42%11%
16081

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%413313436%58%
1620
16th to endDay
10%413323445%56%
1920
February1st to 15thDay
7%413423436%59%
1751
16th to endDay
10%6%25%423447%48%
1579
March1st to 15thDay
5%21332446%9%56%
1800
16th to endDay
4223234349%58%
2196
April1st to 15thDay
6%424323447%57%
2149
16th to endDay
3312123247%67%
2160
May1st to 15thDay
242331335%7%62%
2277
16th to endDay
3313322347%63%
2429
June1st to 15thDay
3312212246%68%
2340
16th to endDay
11212384%
2433
July1st to 15thDay
1212213236%72%
2421
16th to endDay
212213247%70%
2388
August1st to 15thDay
111223481%
2160
16th to endDay
111112235%78%
2292
September1st to 15thDay
11111222479%
2104
16th to endDay
1122122479%
1823
October1st to 15thDay
5%213313346%64%
1815
16th to endDay
5%31321223468%
1742
November1st to 15thDay
321232324468%
1584
16th to endDay
5%323313345%62%
1620
December1st to 15thDay
6%31442345%8%54%
1620
16th to endDay
10%5%24323336%53%
1728
January1st to 15thNight
6%413324346%58%
2316
16th to endNight
9%414413336%55%
2304
February1st to 15thNight
7%422313346%60%
2101
16th to endNight
11%5%24433345%50%
1895
March1st to 15thNight
5%41322346%8%56%
2160
16th to endNight
431332445%9%56%
2024
April1st to 15thNight
7%423323348%55%
1799
16th to endNight
3312223346%65%
1800
May1st to 15thNight
121442436%8%60%
1673
16th to endNight
131332436%7%62%
1684
June1st to 15thNight
131321225%7%68%
1620
16th to endNight
1122483%
1517
July1st to 15thNight
11211245%7%72%
1530
16th to endNight
211122335%7%67%
1777
August1st to 15thNight
111111247%76%
1800
16th to endNight
111123481%
1910
September1st to 15thNight
1112112245%74%
1854
16th to endNight
1212111381%
1826
October1st to 15thNight
3212312245%69%
1815
16th to endNight
431321234467%
2126
November1st to 15thNight
2222213236%69%
2275
16th to endNight
5%314322346%61%
2340
December1st to 15thNight
8%413424446%54%
2340
16th to endNight
10%423323336%56%
2496

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
27%35%12%25%25%
1621
16th to endDay
29%27%14%18%28%
1920
February1st to 15thDay
25%3315%25%26%
1751
16th to endDay
35%26%16%27%10%
1579
March1st to 15thDay
24%37%20%21%22%
1800
16th to endDay
22%312%25%21%14%
2196
April1st to 15thDay
27%37%24%25%11%
2149
16th to endDay
18%29%22%28%18%
2160
May1st to 15thDay
21%27%20%28%18%
2277
16th to endDay
20%37%26%30%10%
2432
June1st to 15thDay
19%26%16%33%22%
2340
16th to endDay
9%137%27%51%
2433
July1st to 15thDay
14%25%9%27%40%
2280
16th to endDay
14%27%22%30%22%
2239
August1st to 15thDay
8%2213%35%37%
2146
16th to endDay
9%2311%36%35%
2292
September1st to 15thDay
10%149%34%38%
2104
16th to endDay
10%1211%35%38%
1823
October1st to 15thDay
20%2419%27%26%
1815
16th to endDay
20%3312%21%38%
1742
November1st to 15thDay
19%17%16%22%33%
1584
16th to endDay
23%3414%21%33%
1620
December1st to 15thDay
27%39%17%17%24%
1620
16th to endDay
31%47%15%21%20%
1728
January1st to 15thNight
26%26%12%21%29%
2316
16th to endNight
30%37%13%15%30%
2304
February1st to 15thNight
26%26%16%22%26%
2112
16th to endNight
35%4414%24%15%
1895
March1st to 15thNight
25%36%21%20%22%
2160
16th to endNight
24%410%20%24%16%
2024
April1st to 15thNight
29%38%24%21%13%
1799
16th to endNight
20%47%23%23%19%
1800
May1st to 15thNight
22%5%6%22%22%20%
1674
16th to endNight
22%6%9%24%23%12%
1685
June1st to 15thNight
18%48%15%31%21%
1620
16th to endNight
7%237%30%47%
1517
July1st to 15thNight
10%4410%29%39%
1443
16th to endNight
16%47%20%30%20%
1663
August1st to 15thNight
9%3314%39%28%
1790
16th to endNight
7%3411%33%39%
1910
September1st to 15thNight
13%35%8%33%36%
1854
16th to endNight
11%1112%33%40%
1826
October1st to 15thNight
18%3418%32%23%
1815
16th to endNight
20%4310%23%38%
2126
November1st to 15thNight
18%2415%23%35%
2275
16th to endNight
24%25%14%19%34%
2340
December1st to 15thNight
28%46%15%19%25%
2340
16th to endNight
30%38%13%23%20%
2496

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
21%214%45%16%1
99
16th to endDay
11%9%27%34%15%1
288
February1st to 15thDay
6%5%30%32%21%4
266
16th to endDay
11%17%22%30%14%2
238
March1st to 15thDay
5%12%27%30%16%7%
270
16th to endDay
5%10%32%33%10%7%
288
April1st to 15thDay
6%15%31%28%12%4
269
16th to endDay
214%37%31%10%4
270
May1st to 15thDay
5%11%26%36%15%4
288
16th to endDay
5%6%24%43%14%5%
330
June1st to 15thDay
3321%39%24%7%
315
16th to endDay
110%39%32%14%
315
July1st to 15thDay
26%37%36%16%
305
16th to endDay
2329%46%16%
327
August1st to 15thDay
15%44%38%9%
315
16th to endDay
1236%43%15%
332
September1st to 15thDay
17%52%29%7%
315
16th to endDay
2214%45%25%8%
258
October1st to 15thDay
5%6%18%45%20%3
255
16th to endDay
7%319%32%28%9%
224
November1st to 15thDay
311%31%26%27%
90
16th to endDay
211%14%35%28%7%
90
December1st to 15thDay
6%210%34%38%7%
90
16th to endDay
9%7%20%35%26%1
96
January1st to 15thNight
7%210%40%28%10%
720
16th to endNight
10%28%38%29%9%
768
February1st to 15thNight
8%29%39%31%9%
704
16th to endNight
12%210%40%26%7%
632
March1st to 15thNight
6%28%43%30%8%
720
16th to endNight
437%39%37%8%
768
April1st to 15thNight
7%39%40%32%5%
719
16th to endNight
429%39%35%8%
720
May1st to 15thNight
329%33%43%7%
594
16th to endNight
2111%35%44%4
563
June1st to 15thNight
216%38%45%4
540
16th to endNight
127%62%7%
437
July1st to 15thNight
1113%69%13%
423
16th to endNight
2110%65%18%
640
August1st to 15thNight
1111%67%17%
717
16th to endNight
18%63%25%
764
September1st to 15thNight
2215%58%20%
720
16th to endNight
2323%53%16%
660
October1st to 15thNight
41437%41%10%
660
16th to endNight
6%16%26%40%18%
704
November1st to 15thNight
315%34%40%15%
700
16th to endNight
5%28%31%37%13%
720
December1st to 15thNight
10%27%37%32%9%
720
16th to endNight
12%412%36%26%8%
768
Page generated at 2017-09-17 09:05:40. Version ac04

Copyright 2017 A. Danko


El Cariso Clear Sky Chart | Charts Home