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Las Dos Scopes
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Las Dos Scopes clear sky chart from 2005-11-06 to 2024-01-15.

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
57%
24234
30%
74522
21%
24183
67%
24183
46%
37729

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
51%
831
34%
2529
21%
828
65%
828
54%
1191
January11th to 20thNight
43%
740
34%
2405
22%
740
59%
740
49%
1135
January21st to endNight
49%
792
35%
2574
22%
792
66%
792
48%
1232
February1st to 10thNight
46%
720
31%
2318
20%
720
60%
720
49%
1100
February11th to 20thNight
39%
702
30%
2098
16%
700
54%
700
45%
1084
February21st to endNight
36%
592
38%
1776
17%
592
57%
592
50%
886
March1st to 10thNight
45%
720
33%
2075
19%
720
57%
720
48%
1078
March11th to 20thNight
51%
720
32%
1980
20%
720
58%
720
45%
1093
March21st to endNight
46%
716
33%
2102
17%
716
61%
716
44%
1106
April1st to 10thNight
42%
540
35%
1800
18%
540
63%
540
48%
825
April11th to 20thNight
41%
533
31%
1777
18%
533
59%
533
42%
860
April21st to endNight
44%
540
33%
1800
20%
540
65%
540
48%
827
May1st to 10thNight
53%
540
30%
1800
23%
540
67%
540
45%
863
May11th to 20thNight
53%
531
24%
1649
20%
531
60%
531
37%
916
May21st to endNight
55%
583
33%
1552
19%
582
67%
582
54%
784
June1st to 10thNight
68%
540
27%
1440
20%
540
73%
540
51%
761
June11th to 20thNight
69%
540
33%
1440
26%
540
72%
540
61%
699
June21st to endNight
73%
540
25%
1440
21%
540
75%
540
47%
810
July1st to 10thNight
73%
525
19%
1400
17%
525
74%
525
35%
878
July11th to 20thNight
76%
522
16%
1564
15%
522
76%
522
36%
888
July21st to endNight
76%
591
12%
1674
11%
558
75%
558
27%
1068
August1st to 10thNight
79%
537
14%
1656
15%
534
79%
534
31%
980
August11th to 20thNight
75%
534
18%
1778
20%
534
76%
534
29%
1060
August21st to endNight
80%
594
23%
1980
27%
594
82%
594
36%
1070
September1st to 10thNight
78%
540
28%
1800
30%
540
80%
540
37%
957
September11th to 20thNight
78%
540
35%
1800
35%
540
81%
540
43%
895
September21st to endNight
70%
575
33%
1997
29%
575
77%
575
49%
908
October1st to 10thNight
60%
720
30%
2160
21%
720
67%
720
43%
1147
October11th to 20thNight
66%
720
42%
2160
26%
720
77%
720
64%
940
October21st to endNight
62%
792
40%
2376
24%
792
73%
792
58%
1092
November1st to 10thNight
65%
791
42%
2271
25%
791
75%
791
69%
976
November11th to 20thNight
64%
950
39%
2470
22%
950
73%
950
67%
1175
November21st to endNight
51%
950
36%
2470
19%
950
61%
950
53%
1328
December1st to 10thNight
50%
950
34%
2626
18%
950
61%
950
52%
1362
December11th to 20thNight
46%
948
29%
3132
17%
948
56%
948
42%
1641
December21st to endNight
39%
1035
19%
4653
14%
1026
53%
1026
33%
2114

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
44234245%6%8%60%
74721
Night
442332445%7%61%
75082
TransparencyDay
21%5%11%23%26%13%
74442
Night
22%5%11%23%27%13%
74883
SeeingDay
5%9%27%31%22%6%
14012
Night
5%329%42%19%2
24250

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
242332346%8%64%
1651
11th to 20thDay
5%5%2331233468%
1660
21st to endDay
442422425%5%64%
1782
February1st to 10thDay
15%25%433346%63%
1641
11th to 20thDay
46%2442346%8%57%
1749
21st to endDay
28%24233347%60%
1480
March1st to 10thDay
35%244345%6%9%55%
1880
11th to 20thDay
37%34423447%59%
1980
21st to endDay
35%234345%5%7%59%
2254
April1st to 10thDay
331342445%8%64%
2160
11th to 20thDay
35%2442445%6%61%
2131
21st to endDay
432331445%8%63%
2160
May1st to 10thDay
322332445%7%65%
2160
11th to 20thDay
43243345%6%8%58%
2239
21st to endDay
321332445%7%66%
2724
June1st to 10thDay
111233447%10%64%
2520
11th to 20thDay
211132345%7%71%
2520
21st to endDay
5%313425%5%6%8%58%
2520
July1st to 10thDay
33245%36%8%8%10%47%
2518
11th to 20thDay
3224447%8%10%12%44%
2340
21st to endDay
4325%7%48%9%11%10%37%
2545
August1st to 10thDay
4215%6%47%7%9%10%45%
2271
11th to 20thDay
43235%45%7%10%9%49%
2123
21st to endDay
43135%36%7%9%11%48%
2376
September1st to 10thDay
6%4145%447%7%8%51%
2160
11th to 20thDay
5%4133345%6%7%60%
2160
21st to endDay
321332325%7%69%
1960
October1st to 10thDay
7%31443445%5%60%
1800
11th to 20thDay
421121222478%
1800
21st to endDay
5%31232323472%
1980
November1st to 10thDay
2312212347%73%
1787
11th to 20thDay
321222345%6%72%
1710
21st to endDay
45%23322436%65%
1710
December1st to 10thDay
35%2322335%7%65%
1550
11th to 20thDay
442443445%8%58%
1926
21st to endDay
45%23323337%65%
2794
January1st to 10thNight
25%13423247%67%
2529
11th to 20thNight
4423333345%65%
2405
21st to endNight
5%5%23313346%64%
2574
February1st to 10thNight
26%44222346%65%
2318
11th to 20thNight
5%7%2432345%7%58%
2098
21st to endNight
37%24323235%65%
1776
March1st to 10thNight
46%3332335%7%60%
2075
11th to 20thNight
47%34334346%59%
1980
21st to endNight
45%24423445%62%
2102
April1st to 10thNight
432332445%7%64%
1800
11th to 20thNight
5%5%2332346%6%60%
1777
21st to endNight
43144235%45%65%
1800
May1st to 10thNight
4314424446%64%
1800
11th to 20thNight
6%5%344345%6%6%55%
1649
21st to endNight
3213323446%68%
1552
June1st to 10thNight
21134346%5%9%61%
1440
11th to 20thNight
3213323446%69%
1440
21st to endNight
4314435%6%6%9%55%
1440
July1st to 10thNight
5%2247%46%7%9%9%46%
1440
11th to 20thNight
34246%45%7%9%11%45%
1617
21st to endNight
5%425%6%38%8%10%13%36%
1773
August1st to 10thNight
3325%5%46%7%9%13%43%
1665
11th to 20thNight
5%5%26%5%46%7%9%12%39%
1778
21st to endNight
33135%36%7%9%12%49%
1980
September1st to 10thNight
5%314436%6%7%10%51%
1800
11th to 20thNight
6%3134245%6%9%57%
1800
21st to endNight
5%412323347%66%
1997
October1st to 10thNight
6%424433445%62%
2160
11th to 20thNight
421222224477%
2160
21st to endNight
421222235%5%70%
2376
November1st to 10thNight
3211212335%78%
2271
11th to 20thNight
2212222345%75%
2470
21st to endNight
6%5%23313345%65%
2470
December1st to 10thNight
46%23323346%64%
2626
11th to 20thNight
45%24425%45%7%58%
3271
21st to endNight
47%24423335%63%
4873

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
17%6%11%34%29%3
1652
11th to 20thDay
19%310%32%31%5%
1660
21st to endDay
21%49%28%30%7%
1782
February1st to 10thDay
22%413%28%24%8%
1641
11th to 20thDay
23%49%29%26%9%
1759
21st to endDay
23%36%21%33%14%
1480
March1st to 10thDay
23%48%25%29%12%
1880
11th to 20thDay
25%39%22%30%11%
1980
21st to endDay
22%49%26%28%11%
2254
April1st to 10thDay
17%48%23%30%17%
2160
11th to 20thDay
22%5%7%20%30%17%
2134
21st to endDay
18%49%24%30%15%
2160
May1st to 10thDay
17%47%21%33%18%
2160
11th to 20thDay
23%6%11%22%25%13%
2242
21st to endDay
17%410%20%25%24%
2724
June1st to 10thDay
14%5%13%21%25%22%
2520
11th to 20thDay
13%36%15%25%39%
2520
21st to endDay
22%5%9%19%24%21%
2520
July1st to 10thDay
27%8%15%17%17%14%
2449
11th to 20thDay
23%9%22%25%13%7%
2271
21st to endDay
30%13%26%23%6%1
2404
August1st to 10thDay
28%11%21%20%13%8%
2256
11th to 20thDay
24%9%17%24%18%7%
2123
21st to endDay
23%9%18%26%20%4
2376
September1st to 10thDay
26%7%13%25%20%10%
2160
11th to 20thDay
21%6%13%20%25%16%
2160
21st to endDay
15%37%24%34%16%
1960
October1st to 10thDay
25%5%9%21%26%16%
1800
11th to 20thDay
14%1414%41%25%
1800
21st to endDay
17%28%22%37%13%
1980
November1st to 10thDay
12%27%25%38%15%
1787
11th to 20thDay
14%48%28%38%9%
1710
21st to endDay
21%36%25%34%12%
1710
December1st to 10thDay
19%314%33%24%7%
1550
11th to 20thDay
24%5%12%27%27%5%
1924
21st to endDay
20%5%9%26%31%9%
2794
January1st to 10thNight
18%311%33%30%4
2529
11th to 20thNight
20%310%32%29%6%
2405
21st to endNight
21%39%29%31%7%
2574
February1st to 10thNight
21%313%27%27%10%
2318
11th to 20thNight
24%39%28%25%10%
2098
21st to endNight
22%26%20%34%16%
1776
March1st to 10thNight
23%46%26%29%13%
2075
11th to 20thNight
26%38%22%31%11%
1980
21st to endNight
24%46%21%33%11%
2102
April1st to 10thNight
18%47%23%31%17%
1800
11th to 20thNight
23%48%19%26%20%
1777
21st to endNight
19%410%20%33%14%
1800
May1st to 10thNight
21%5%6%17%32%19%
1800
11th to 20thNight
27%7%11%19%20%16%
1650
21st to endNight
16%5%11%19%24%24%
1552
June1st to 10thNight
18%7%16%20%20%20%
1440
11th to 20thNight
14%48%14%22%38%
1440
21st to endNight
24%6%13%17%19%22%
1440
July1st to 10thNight
30%10%17%16%13%14%
1400
11th to 20thNight
26%10%24%18%13%9%
1564
21st to endNight
33%14%29%17%7%1
1674
August1st to 10thNight
28%13%21%17%12%9%
1656
11th to 20thNight
31%11%21%19%11%7%
1778
21st to endNight
24%11%18%25%15%7%
1980
September1st to 10thNight
25%8%16%24%16%10%
1800
11th to 20thNight
22%6%15%15%24%18%
1800
21st to endNight
18%5%10%19%31%17%
1997
October1st to 10thNight
24%5%10%19%23%19%
2160
11th to 20thNight
13%35%16%38%26%
2160
21st to endNight
15%36%24%36%16%
2376
November1st to 10thNight
10%27%25%40%15%
2271
11th to 20thNight
12%38%26%39%12%
2470
21st to endNight
22%36%23%32%14%
2470
December1st to 10thNight
21%310%33%27%6%
2626
11th to 20thNight
23%5%13%27%27%5%
3272
21st to endNight
24%5%10%26%31%5%
4873

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
5%8%47%29%9%1
270
11th to 20thDay
12%6%47%28%6%1
254
21st to endDay
410%44%29%11%2
264
February1st to 10thDay
216%40%32%10%
240
11th to 20thDay
8%15%44%25%8%
240
21st to endDay
9%17%46%22%6%1
198
March1st to 10thDay
5%21%32%32%9%
320
11th to 20thDay
10%16%35%25%13%1
420
21st to endDay
10%27%35%19%8%
462
April1st to 10thDay
6%18%43%24%8%1
420
11th to 20thDay
10%24%36%21%8%1
412
21st to endDay
7%23%39%25%6%
420
May1st to 10thDay
414%43%28%10%1
423
11th to 20thDay
5%13%32%30%16%3
499
21st to endDay
411%31%35%18%2
679
June1st to 10thDay
27%20%39%29%3
630
11th to 20thDay
25%24%38%27%4
630
21st to endDay
6%319%35%29%7%
630
July1st to 10thDay
3111%33%39%12%
619
11th to 20thDay
417%25%40%23%
444
21st to endDay
325%26%40%24%
487
August1st to 10thDay
5%27%28%40%17%
447
11th to 20thDay
5%213%31%38%11%
437
21st to endDay
4210%35%35%15%
495
September1st to 10thDay
6%212%36%34%10%
450
11th to 20thDay
4121%37%30%7%
450
21st to endDay
47%17%34%29%9%
288
October1st to 10thDay
7%9%26%28%26%4
270
11th to 20thDay
6%7%29%29%26%4
270
21st to endDay
9%8%24%34%21%4
297
November1st to 10thDay
5%13%33%35%14%
270
11th to 20thDay
36%30%41%18%2
270
21st to endDay
8%10%40%26%13%3
270
December1st to 10thDay
5%7%43%32%11%2
270
11th to 20thDay
5%14%38%33%9%1
270
21st to endDay
11%11%46%26%7%
297
January1st to 10thNight
4336%44%12%
832
11th to 20thNight
6%244%36%11%1
740
21st to endNight
8%237%41%10%2
792
February1st to 10thNight
5%341%43%8%
720
11th to 20thNight
8%5%44%37%6%
704
21st to endNight
7%253%36%2
592
March1st to 10thNight
6%440%42%8%
720
11th to 20thNight
6%6%33%43%12%
720
21st to endNight
5%6%38%42%8%
716
April1st to 10thNight
5%6%45%37%7%
540
11th to 20thNight
7%7%40%36%10%
533
21st to endNight
5%5%43%39%8%
540
May1st to 10thNight
45%33%46%11%
540
11th to 20thNight
6%6%25%42%19%2
531
21st to endNight
47%29%47%13%
584
June1st to 10thNight
2420%48%25%1
540
11th to 20thNight
2223%53%20%1
540
21st to endNight
4213%50%30%1
540
July1st to 10thNight
5%28%41%43%2
525
11th to 20thNight
42436%48%6%
522
21st to endNight
5%1329%52%9%
591
August1st to 10thNight
41427%55%8%
537
11th to 20thNight
5%45%41%41%4
534
21st to endNight
335%38%47%4
594
September1st to 10thNight
6%18%44%39%2
540
11th to 20thNight
6%27%49%34%2
540
21st to endNight
5%218%46%27%2
575
October1st to 10thNight
6%422%45%22%1
720
11th to 20thNight
4125%49%19%2
720
21st to endNight
5%326%43%20%3
792
November1st to 10thNight
4227%47%18%1
791
11th to 20thNight
3228%49%15%2
950
21st to endNight
8%434%36%17%1
950
December1st to 10thNight
6%338%44%10%1
950
11th to 20thNight
7%5%39%40%9%1
950
21st to endNight
9%443%37%7%
1045
Page generated at 2024-01-12 14:17:46. Version ac07

Copyright 2024 Attilla Danko


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