Edinburg
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Edinburg clear sky chart from 2005-11-05 to 2017-09-24.

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
0%
5770
0%
25970
0%
4080
0%
4080
33%
27455

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
0%
469
0%
1329
0%
352
0%
352
28%
1573
January16th to endNight
0%
381
0%
1257
0%
253
0%
253
29%
1425
February1st to 15thNight
0%
398
0%
1067
0%
255
0%
255
31%
1268
February16th to endNight
0%
392
0%
960
0%
234
0%
234
31%
1109
March1st to 15thNight
0%
310
0%
1066
0%
208
0%
208
26%
1140
March16th to endNight
0%
359
0%
1181
0%
245
0%
245
26%
1206
April1st to 15thNight
0%
336
0%
1155
0%
223
0%
223
26%
1126
April16th to endNight
0%
339
0%
1148
0%
239
0%
239
21%
1210
May1st to 15thNight
0%
329
0%
1064
0%
249
0%
249
26%
1044
May16th to endNight
0%
246
0%
966
0%
156
0%
156
35%
992
June1st to 15thNight
0%
74
0%
722
0%
50
0%
50
50%
810
June16th to endNight
0%
96
0%
915
0%
79
0%
79
38%
913
July1st to 15thNight
0%
85
0%
987
0%
71
0%
71
34%
907
July16th to endNight
0%
41
0%
919
0%
29
0%
29
53%
774
August1st to 15thNight
0%
25
0%
952
0%
14
0%
14
53%
804
August16th to endNight
0%
61
0%
1289
0%
51
0%
51
34%
1106
September1st to 15thNight
0%
61
0%
1235
0%
54
0%
54
28%
1142
September16th to endNight
0%
76
0%
1234
0%
70
0%
70
25%
1141
October1st to 15thNight
0%
63
0%
740
0%
44
0%
44
41%
858
October16th to endNight
0%
172
0%
794
0%
122
0%
122
43%
1091
November1st to 15thNight
0%
226
0%
1069
0%
176
0%
176
35%
1224
November16th to endNight
0%
313
0%
1131
0%
214
0%
214
37%
1345
December1st to 15thNight
0%
410
0%
1386
0%
321
0%
321
29%
1592
December16th to endNight
0%
508
0%
1404
0%
371
0%
371
30%
1655

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
TransparencyDay
35%7%13%21%15%6%
47523
Night
31%6%16%22%14%7%
47096
SeeingDay
8%219%37%23%7%
5061
Night
11%323%38%21%2
15168

By Month

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
45%5%9%15%14%8%
1612
16th to endDay
36%5%10%18%17%11%
1917
February1st to 15thDay
37%38%18%19%13%
1751
16th to endDay
35%39%21%20%9%
1591
March1st to 15thDay
40%5%9%17%16%10%
1980
16th to endDay
35%5%12%18%15%11%
2112
April1st to 15thDay
33%6%12%22%17%8%
1971
16th to endDay
36%6%11%17%18%8%
2031
May1st to 15thDay
36%7%13%21%14%7%
2331
16th to endDay
32%9%14%21%18%4
2434
June1st to 15thDay
24%7%15%26%20%5%
2340
16th to endDay
35%10%15%23%13%1
2340
July1st to 15thDay
38%8%16%24%11%
2201
16th to endDay
27%9%22%30%9%
2294
August1st to 15thDay
25%7%19%37%8%
2147
16th to endDay
38%10%20%22%7%
2184
September1st to 15thDay
48%10%12%16%9%2
1980
16th to endDay
42%12%15%14%11%4
1904
October1st to 15thDay
29%6%10%20%24%8%
1815
16th to endDay
27%5%10%20%21%14%
1775
November1st to 15thDay
38%6%11%17%17%8%
1758
16th to endDay
35%5%8%17%17%15%
1707
December1st to 15thDay
43%6%11%16%13%8%
1620
16th to endDay
41%410%16%18%8%
1728
January1st to 15thNight
43%49%17%14%11%
2327
16th to endNight
37%5%11%17%17%10%
2316
February1st to 15thNight
35%410%17%16%15%
2112
16th to endNight
35%411%18%20%10%
1882
March1st to 15thNight
36%5%12%19%16%10%
1980
16th to endNight
34%6%14%17%17%8%
2112
April1st to 15thNight
34%6%17%20%14%6%
1977
16th to endNight
40%8%10%18%15%6%
1923
May1st to 15thNight
36%10%18%17%11%5%
1620
16th to endNight
28%9%19%24%16%1
1685
June1st to 15thNight
16%8%19%29%21%3
1620
16th to endNight
25%8%22%30%12%
1620
July1st to 15thNight
28%10%25%28%6%
1530
16th to endNight
14%7%34%35%6%
1606
August1st to 15thNight
13%7%32%41%4
1789
16th to endNight
26%10%27%28%6%1
2018
September1st to 15thNight
31%9%21%27%8%2
1980
16th to endNight
32%11%20%19%11%4
1914
October1st to 15thNight
21%6%13%27%24%7%
1815
16th to endNight
23%5%8%23%23%14%
2084
November1st to 15thNight
31%5%13%21%19%8%
2100
16th to endNight
32%413%17%15%16%
2250
December1st to 15thNight
41%6%11%18%13%8%
2340
16th to endNight
40%411%16%16%10%
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%6%27%31%11%2
90
16th to endDay
12%6%39%27%12%2
96
February1st to 15thDay
25%34%28%26%2
90
16th to endDay
8%7%39%32%11%1
81
March1st to 15thDay
28%326%30%10%1
90
16th to endDay
11%440%39%4
96
April1st to 15thDay
7%438%36%11%1
90
16th to endDay
8%9%34%32%11%4
141
May1st to 15thDay
11%446%29%7%
468
16th to endDay
5%338%39%11%1
517
June1st to 15thDay
410%47%28%8%
495
16th to endDay
6%111%44%26%10%
495
July1st to 15thDay
8%10%42%31%6%
475
16th to endDay
41341%39%10%
497
August1st to 15thDay
355%28%11%
315
16th to endDay
5%110%41%24%17%
224
September1st to 15thDay
13%325%40%16%
135
16th to endDay
5%2121%35%32%
114
October1st to 15thDay
6%214%43%33%
90
16th to endDay
15%27%29%35%10%
96
November1st to 15thDay
33%310%35%13%4
90
16th to endDay
20%330%22%14%10%
90
December1st to 15thDay
28%321%18%18%8%
90
16th to endDay
25%6%29%21%12%5%
96
January1st to 15thNight
23%424%35%12%
900
16th to endNight
17%427%42%8%
780
February1st to 15thNight
16%5%34%35%7%
704
16th to endNight
18%341%30%5%
620
March1st to 15thNight
14%6%36%35%6%
540
16th to endNight
11%446%33%3
576
April1st to 15thNight
11%5%46%32%5%
539
16th to endNight
12%445%32%4
540
May1st to 15thNight
7%448%33%5%
540
16th to endNight
5%235%46%9%
563
June1st to 15thNight
210%57%28%
540
16th to endNight
4111%50%28%2
540
July1st to 15thNight
7%9%52%29%2
510
16th to endNight
3349%40%3
564
August1st to 15thNight
345%45%4
539
16th to endNight
6%434%48%6%
573
September1st to 15thNight
7%328%50%8%
540
16th to endNight
9%1429%47%9%
519
October1st to 15thNight
48%36%45%5%
495
16th to endNight
6%216%41%30%2
676
November1st to 15thNight
11%317%41%24%1
700
16th to endNight
13%222%39%19%2
810
December1st to 15thNight
19%322%38%14%1
900
16th to endNight
22%5%24%31%15%
960
Page generated at 2017-09-25 08:02:20. Version ac04

Copyright 2017 A. Danko


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