Ensenada
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Ensenada clear sky chart from 2005-11-05 to 2017-09-23.

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
65%
16296
28%
47052
22%
16251
71%
16251
33%
27050

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%
2304
26%
716
69%
716
33%
1188
January16th to endNight
57%
768
34%
2304
26%
768
68%
768
32%
1276
February1st to 15thNight
61%
700
31%
2112
30%
700
65%
700
33%
1177
February16th to endNight
55%
632
26%
1895
23%
632
63%
632
26%
1171
March1st to 15thNight
64%
720
30%
2145
28%
720
70%
720
38%
1140
March16th to endNight
63%
768
25%
2067
21%
768
68%
768
33%
1252
April1st to 15thNight
61%
719
26%
1799
18%
719
63%
719
35%
1115
April16th to endNight
63%
720
29%
1800
16%
720
67%
720
38%
1068
May1st to 15thNight
61%
590
21%
1670
13%
590
64%
590
25%
1102
May16th to endNight
55%
561
19%
1685
10%
561
58%
561
21%
1129
June1st to 15thNight
60%
540
15%
1620
9%
540
64%
540
18%
1119
June16th to endNight
72%
540
24%
1620
14%
540
78%
540
29%
946
July1st to 15thNight
69%
510
17%
1530
12%
510
71%
510
28%
916
July16th to endNight
66%
650
22%
1672
14%
610
73%
610
27%
1089
August1st to 15thNight
75%
717
18%
1790
10%
713
77%
713
28%
1220
August16th to endNight
77%
764
31%
1910
18%
764
81%
764
43%
1120
September1st to 15thNight
79%
720
29%
1893
24%
720
81%
720
42%
1076
September16th to endNight
79%
688
37%
1903
31%
688
85%
688
47%
988
October1st to 15thNight
73%
660
33%
1815
32%
660
75%
660
47%
956
October16th to endNight
71%
704
35%
2067
30%
704
77%
704
40%
1100
November1st to 15thNight
69%
700
32%
2275
33%
700
74%
700
40%
1094
November16th to endNight
65%
720
33%
2340
31%
720
74%
720
36%
1155
December1st to 15thNight
56%
720
30%
2340
28%
720
63%
720
29%
1278
December16th to endNight
54%
768
30%
2496
25%
768
64%
768
28%
1375

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
4212323347%63%
47845
Night
5%413434447%55%
47255
TransparencyDay
22%37%18%24%23%
47548
Night
31%36%14%20%24%
47053
SeeingDay
5%14%23%38%13%4
5961
Night
6%15%326%34%13%
16306

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%312223437%59%
1632
16th to endDay
8%413324347%55%
1920
February1st to 15thDay
6%31332436%6%57%
1751
16th to endDay
9%5%2433435%8%47%
1579
March1st to 15thDay
6%21332335%7%59%
1815
16th to endDay
5%31322345%7%59%
2154
April1st to 15thDay
5%31332445%7%58%
2149
16th to endDay
5%212213246%67%
2160
May1st to 15thDay
4312323347%63%
2277
16th to endDay
3423323227%64%
2429
June1st to 15thDay
1212435%447%61%
2340
16th to endDay
11224337%72%
2340
July1st to 15thDay
121342445%8%60%
2340
16th to endDay
11133345%6%10%57%
2378
August1st to 15thDay
112313437%70%
2160
16th to endDay
112223447%69%
2292
September1st to 15thDay
211323335%70%
2067
16th to endDay
1111212481%
1893
October1st to 15thDay
3312212337%67%
1815
16th to endDay
42221233471%
1802
November1st to 15thDay
322224236%67%
1584
16th to endDay
5%212313246%65%
1620
December1st to 15thDay
8%41432245%7%55%
1620
16th to endDay
9%413315%446%54%
1728
January1st to 15thNight
5%323324347%59%
2304
16th to endNight
9%313323446%56%
2304
February1st to 15thNight
6%424423346%55%
2101
16th to endNight
12%5%2443445%5%47%
1895
March1st to 15thNight
7%413323346%59%
2145
16th to endNight
5%433435%45%8%51%
2067
April1st to 15thNight
7%6%2432435%7%53%
1799
16th to endNight
6%322324247%60%
1800
May1st to 15thNight
5%6%25%5%47%348%46%
1670
16th to endNight
410%45%5%5%4436%45%
1684
June1st to 15thNight
25%35%9%9%6%6%5%7%37%
1620
16th to endNight
1125%6%6%6%5%9%53%
1620
July1st to 15thNight
1415%6%5%5%5%6%8%47%
1620
16th to endNight
1215%8%6%8%5%6%7%47%
1787
August1st to 15thNight
2246%7%6%7%6%10%44%
1800
16th to endNight
11135%35%5%47%60%
1910
September1st to 15thNight
1113324447%64%
1893
16th to endNight
212223225%73%
1903
October1st to 15thNight
4312314336%64%
1815
16th to endNight
4313323346%64%
2067
November1st to 15thNight
4212413335%66%
2275
16th to endNight
5%413223346%62%
2340
December1st to 15thNight
8%42242445%7%54%
2340
16th to endNight
9%5%23422346%54%
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
24%28%14%20%29%
1633
16th to endDay
28%38%12%19%28%
1920
February1st to 15thDay
25%37%14%19%29%
1751
16th to endDay
33%47%17%23%14%
1579
March1st to 15thDay
24%37%16%22%26%
1815
16th to endDay
24%49%21%25%14%
2154
April1st to 15thDay
24%48%24%26%11%
2149
16th to endDay
18%28%25%25%19%
2160
May1st to 15thDay
24%27%23%23%18%
2277
16th to endDay
22%27%23%31%11%
2432
June1st to 15thDay
22%37%19%22%23%
2340
16th to endDay
14%15%16%19%42%
2340
July1st to 15thDay
21%35%19%25%23%
2201
16th to endDay
23%5%13%23%23%10%
2230
August1st to 15thDay
17%38%19%29%21%
2146
16th to endDay
17%47%18%26%25%
2292
September1st to 15thDay
18%25%17%31%24%
2067
16th to endDay
11%25%15%34%30%
1893
October1st to 15thDay
18%47%17%24%27%
1815
16th to endDay
18%25%15%20%37%
1802
November1st to 15thDay
19%26%17%18%34%
1584
16th to endDay
21%26%15%20%33%
1620
December1st to 15thDay
28%38%17%18%24%
1620
16th to endDay
30%410%14%19%20%
1728
January1st to 15thNight
26%36%14%19%29%
2304
16th to endNight
28%46%15%14%30%
2304
February1st to 15thNight
29%35%13%16%31%
2112
16th to endNight
37%4414%21%17%
1895
March1st to 15thNight
26%27%17%19%26%
2145
16th to endNight
32%48%15%22%16%
2067
April1st to 15thNight
32%46%21%22%13%
1799
16th to endNight
29%26%19%21%20%
1800
May1st to 15thNight
41%47%13%15%18%
1671
16th to endNight
46%3414%18%12%
1685
June1st to 15thNight
47%4410%15%16%
1620
16th to endNight
34%1211%16%33%
1620
July1st to 15thNight
35%3415%18%21%
1530
16th to endNight
39%5%9%20%20%5%
1672
August1st to 15thNight
41%45%13%22%12%
1790
16th to endNight
26%45%14%27%22%
1910
September1st to 15thNight
25%4411%25%28%
1893
16th to endNight
21%2212%31%28%
1903
October1st to 15thNight
22%37%15%23%28%
1815
16th to endNight
26%2311%20%35%
2067
November1st to 15thNight
22%25%17%15%36%
2275
16th to endNight
24%27%14%18%32%
2340
December1st to 15thNight
30%47%14%19%23%
2340
16th to endNight
30%49%15%17%21%
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
16%13%22%36%9%
111
16th to endDay
10%22%28%28%9%
288
February1st to 15thDay
7%17%31%29%12%
266
16th to endDay
10%23%31%25%7%1
238
March1st to 15thDay
5%21%30%28%10%3
270
16th to endDay
5%22%31%28%7%4
288
April1st to 15thDay
7%24%34%21%9%3
269
16th to endDay
324%35%26%7%2
270
May1st to 15thDay
9%19%33%28%6%2
288
16th to endDay
419%35%29%9%2
330
June1st to 15thDay
214%27%37%15%2
315
16th to endDay
110%13%52%14%7%
315
July1st to 15thDay
27%10%55%20%4
305
16th to endDay
110%352%23%8%
327
August1st to 15thDay
26%12%54%16%7%
315
16th to endDay
25%8%53%21%9%
332
September1st to 15thDay
5%5%18%52%13%4
315
16th to endDay
6%9%26%44%10%3
284
October1st to 15thDay
216%36%30%11%2
255
16th to endDay
8%11%22%33%18%6%
214
November1st to 15thDay
113%15%38%24%6%
90
16th to endDay
7%10%25%33%16%6%
90
December1st to 15thDay
410%16%40%25%3
90
16th to endDay
13%9%21%36%15%3
96
January1st to 15thNight
5%19%5%33%27%8%
720
16th to endNight
10%18%7%30%25%7%
768
February1st to 15thNight
8%19%433%27%6%
704
16th to endNight
12%17%5%35%21%7%
632
March1st to 15thNight
6%18%5%35%26%7%
720
16th to endNight
5%18%332%30%8%
768
April1st to 15thNight
7%18%434%28%6%
719
16th to endNight
6%19%430%30%8%
720
May1st to 15thNight
7%17%430%31%7%
591
16th to endNight
5%21%6%26%34%5%
563
June1st to 15thNight
318%230%38%7%
540
16th to endNight
116%122%48%9%
540
July1st to 15thNight
212%112%53%18%
510
16th to endNight
216%5%49%25%
650
August1st to 15thNight
19%8%49%29%
717
16th to endNight
28%7%44%35%
764
September1st to 15thNight
28%12%51%23%
720
16th to endNight
49%123%40%19%
688
October1st to 15thNight
5%10%330%38%11%
660
16th to endNight
412%324%34%20%
704
November1st to 15thNight
415%432%30%12%
700
16th to endNight
6%18%229%28%14%
720
December1st to 15thNight
10%18%6%31%25%8%
720
16th to endNight
12%19%5%32%23%6%
768
Page generated at 2017-09-24 06:15:49. Version ac04

Copyright 2017 A. Danko


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