Lake Amistad
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake Amistad clear sky chart from 2005-11-06 to 2024-01-31.

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%
23733
29%
74601
22%
23684
65%
23684
40%
39820

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
54%
946
32%
2458
18%
946
62%
946
45%
1405
January11th to 20thNight
53%
760
32%
2280
20%
760
62%
760
38%
1254
January21st to endNight
46%
834
32%
2502
19%
834
58%
834
35%
1422
February1st to 10thNight
48%
720
32%
2160
18%
720
60%
720
40%
1157
February11th to 20thNight
41%
704
25%
2098
13%
700
51%
700
36%
1172
February21st to endNight
41%
592
31%
1776
15%
592
54%
592
38%
975
March1st to 10thNight
39%
720
27%
2160
13%
720
51%
720
35%
1216
March11th to 20thNight
41%
556
25%
1996
18%
556
51%
556
30%
1105
March21st to endNight
37%
594
29%
2178
18%
594
54%
594
37%
1062
April1st to 10thNight
40%
540
32%
1846
17%
540
59%
540
39%
953
April11th to 20thNight
31%
533
30%
1777
15%
533
50%
533
34%
971
April21st to endNight
34%
540
32%
1800
17%
540
54%
540
37%
954
May1st to 10thNight
40%
540
27%
1724
19%
540
52%
540
35%
962
May11th to 20thNight
45%
531
24%
1593
18%
531
55%
531
36%
935
May21st to endNight
47%
582
24%
1745
19%
582
57%
582
34%
1027
June1st to 10thNight
68%
540
26%
1620
26%
540
73%
540
55%
782
June11th to 20thNight
65%
540
27%
1620
24%
540
73%
540
51%
790
June21st to endNight
68%
540
26%
1620
27%
540
72%
540
45%
859
July1st to 10thNight
70%
525
17%
1575
19%
525
72%
525
35%
940
July11th to 20thNight
80%
522
33%
1566
35%
522
85%
522
52%
766
July21st to endNight
83%
591
29%
1859
36%
558
88%
558
55%
809
August1st to 10thNight
88%
537
32%
1779
39%
534
90%
534
61%
732
August11th to 20thNight
82%
534
29%
1778
35%
534
85%
534
44%
875
August21st to endNight
81%
594
25%
1980
29%
594
83%
594
39%
1047
September1st to 10thNight
77%
540
23%
1912
27%
540
78%
540
34%
1060
September11th to 20thNight
71%
540
23%
1980
25%
540
73%
540
31%
1082
September21st to endNight
75%
540
27%
1980
30%
540
76%
540
37%
995
October1st to 10thNight
71%
540
34%
1980
35%
540
73%
540
40%
949
October11th to 20thNight
63%
540
35%
1980
31%
540
71%
540
36%
1004
October21st to endNight
62%
684
38%
2268
28%
684
70%
684
47%
1074
November1st to 10thNight
61%
901
31%
2381
18%
901
65%
901
45%
1351
November11th to 20thNight
60%
950
29%
2470
16%
950
65%
950
48%
1384
November21st to endNight
54%
950
32%
2470
17%
950
60%
950
40%
1464
December1st to 10thNight
58%
950
33%
2470
19%
950
63%
950
42%
1462
December11th to 20thNight
49%
949
29%
2899
16%
948
55%
948
33%
1715
December21st to endNight
51%
1034
21%
4321
17%
1026
59%
1026
32%
2110

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
11%42442445%7%54%
74987
Night
9%42332345%7%57%
75169
TransparencyDay
31%410%22%21%12%
74724
Night
27%411%21%22%15%
74952
SeeingDay
12%317%35%27%6%
13610
Night
11%323%46%16%1
23751

By Month

Percentage Cloud Cover SE (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
11%5%24323345%59%
1721
11th to 20thDay
12%6%23313346%57%
1900
21st to endDay
11%5%24423447%55%
2080
February1st to 10thDay
12%6%25%323345%55%
1800
11th to 20thDay
14%5%2442335%7%52%
1749
21st to endDay
10%424334346%58%
1480
March1st to 10thDay
14%7%3432334453%
1800
11th to 20thDay
14%6%25%324446%50%
1962
21st to endDay
13%5%13423447%55%
2178
April1st to 10thDay
11%5%235%2335%8%51%
2110
11th to 20thDay
13%423223346%56%
2134
21st to endDay
14%424324346%53%
2160
May1st to 10thDay
13%4244345%6%7%47%
2232
11th to 20thDay
14%5%25%42446%8%45%
2302
21st to endDay
14%6%35%435%47%10%40%
2531
June1st to 10thDay
5%3133345%6%10%58%
2340
11th to 20thDay
7%323425%5%5%9%55%
2340
21st to endDay
6%324435%6%7%9%50%
2340
July1st to 10thDay
10%435%5%36%5%5%8%45%
2340
11th to 20thDay
421332346%8%63%
2336
21st to endDay
5%223424448%62%
2349
August1st to 10thDay
211332345%8%68%
2149
11th to 20thDay
42223246%7%10%58%
2123
21st to endDay
6%3245%345%5%9%55%
2376
September1st to 10thDay
11%426%5%36%5%6%7%46%
2048
11th to 20thDay
11%5%26%5%445%6%8%45%
1980
21st to endDay
7%42443445%8%53%
1980
October1st to 10thDay
8%424325%45%6%56%
1980
11th to 20thDay
14%42442345%5%52%
1980
21st to endDay
14%323322235%62%
2069
November1st to 10thDay
15%423323346%54%
1692
11th to 20thDay
11%6%24332336%58%
1710
21st to endDay
13%6%26%413435%53%
1710
December1st to 10thDay
14%7%25%41345%6%50%
1710
11th to 20thDay
13%7%24424447%49%
2161
21st to endDay
13%6%2332233458%
3135
January1st to 10thNight
10%5%24223447%58%
2458
11th to 20thNight
12%6%23323346%58%
2280
21st to endNight
12%5%2442345%7%54%
2502
February1st to 10thNight
8%5%24423347%59%
2160
11th to 20thNight
13%6%24323336%57%
2098
21st to endNight
10%32333345%7%56%
1776
March1st to 10thNight
11%42433445%8%53%
2160
11th to 20thNight
11%5%25%42446%6%52%
1996
21st to endNight
10%323323347%60%
2178
April1st to 10thNight
8%41332445%8%57%
1846
11th to 20thNight
12%5%14333446%55%
1777
21st to endNight
11%5%23323345%59%
1800
May1st to 10thNight
10%5%245%235%46%54%
1724
11th to 20thNight
9%5%245%25%5%5%8%50%
1593
21st to endNight
9%5%25%4345%6%10%48%
1745
June1st to 10thNight
321232445%12%63%
1620
11th to 20thNight
22123245%5%9%64%
1620
21st to endNight
7%2124345%6%10%56%
1620
July1st to 10thNight
9%4245%45%6%6%11%46%
1620
11th to 20thNight
32133235%5%8%66%
1620
21st to endNight
5%21222345%9%65%
1969
August1st to 10thNight
1112213348%72%
1790
11th to 20thNight
421333445%10%60%
1778
21st to endNight
5%213435%5%7%11%54%
1980
September1st to 10thNight
7%425%425%5%6%8%53%
1912
11th to 20thNight
9%425%5%3346%8%50%
1980
21st to endNight
7%424334448%57%
1980
October1st to 10thNight
8%42332435%6%61%
1980
11th to 20thNight
12%31332345%5%58%
1980
21st to endNight
9%31331223370%
2268
November1st to 10thNight
13%423312335%62%
2381
11th to 20thNight
9%42332235%6%61%
2470
21st to endNight
12%424333446%56%
2470
December1st to 10thNight
12%423324347%55%
2470
11th to 20thNight
12%5%24423346%53%
3036
21st to endNight
11%5%1331345%9%56%
4532

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
29%35%18%26%19%
1722
11th to 20thDay
31%36%17%23%19%
1900
21st to endDay
31%47%15%27%16%
2080
February1st to 10thDay
33%36%14%23%21%
1800
11th to 20thDay
34%37%20%21%15%
1759
21st to endDay
29%47%15%24%21%
1480
March1st to 10thDay
38%36%20%18%16%
1800
11th to 20thDay
37%48%14%15%22%
1962
21st to endDay
30%410%18%18%20%
2178
April1st to 10thDay
33%37%19%20%17%
2110
11th to 20thDay
30%48%20%19%19%
2134
21st to endDay
33%37%20%18%18%
2160
May1st to 10thDay
34%6%8%20%20%12%
2232
11th to 20thDay
37%412%23%17%7%
2306
21st to endDay
39%5%11%23%17%4
2531
June1st to 10thDay
21%6%14%30%22%7%
2340
11th to 20thDay
26%5%12%27%23%7%
2340
21st to endDay
30%6%15%24%19%6%
2340
July1st to 10thDay
36%7%16%25%15%2
2276
11th to 20thDay
18%5%16%34%23%4
2267
21st to endDay
18%5%22%35%19%1
2219
August1st to 10thDay
15%414%41%24%3
2136
11th to 20thDay
21%7%20%31%19%3
2123
21st to endDay
26%7%16%28%18%5%
2376
September1st to 10thDay
37%7%12%21%17%6%
2048
11th to 20thDay
36%6%14%19%20%4
1980
21st to endDay
30%5%12%22%20%11%
1980
October1st to 10thDay
28%6%10%24%22%11%
1980
11th to 20thDay
33%49%16%20%16%
1980
21st to endDay
28%2416%28%22%
2069
November1st to 10thDay
33%310%21%20%13%
1692
11th to 20thDay
31%39%20%20%17%
1710
21st to endDay
35%37%18%21%16%
1710
December1st to 10thDay
36%48%18%24%11%
1710
11th to 20thDay
36%38%15%21%16%
2159
21st to endDay
32%25%16%26%20%
3135
January1st to 10thNight
28%36%16%24%23%
2458
11th to 20thNight
30%36%17%25%19%
2280
21st to endNight
32%36%15%23%21%
2502
February1st to 10thNight
28%39%16%20%24%
2160
11th to 20thNight
32%37%18%22%19%
2098
21st to endNight
28%5%8%15%22%22%
1776
March1st to 10thNight
31%410%20%19%16%
2160
11th to 20thNight
33%5%10%13%17%23%
1996
21st to endNight
26%313%20%17%21%
2178
April1st to 10thNight
26%411%20%19%19%
1846
11th to 20thNight
31%49%20%16%21%
1777
21st to endNight
28%410%22%20%16%
1800
May1st to 10thNight
31%5%11%20%19%14%
1724
11th to 20thNight
32%6%11%25%20%7%
1594
21st to endNight
32%6%15%23%20%4
1746
June1st to 10thNight
15%6%16%32%24%6%
1620
11th to 20thNight
17%6%13%30%23%10%
1620
21st to endNight
24%5%15%27%22%8%
1620
July1st to 10thNight
30%8%18%24%17%2
1575
11th to 20thNight
16%7%11%32%26%8%
1566
21st to endNight
13%6%22%35%21%3
1859
August1st to 10thNight
12%413%39%28%4
1779
11th to 20thNight
20%7%17%32%19%5%
1778
21st to endNight
24%8%18%26%18%5%
1980
September1st to 10thNight
29%7%14%24%17%8%
1912
11th to 20thNight
31%7%18%22%17%5%
1980
21st to endNight
26%5%13%22%20%13%
1980
October1st to 10thNight
25%411%24%23%13%
1980
11th to 20thNight
28%49%21%21%16%
1980
21st to endNight
22%27%15%30%24%
2268
November1st to 10thNight
28%38%21%25%16%
2381
11th to 20thNight
25%39%21%22%18%
2470
21st to endNight
31%48%19%20%19%
2470
December1st to 10thNight
30%310%20%21%15%
2470
11th to 20thNight
33%47%15%22%19%
3037
21st to endNight
27%37%17%26%19%
4532

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
16%6%26%38%14%1
270
11th to 20thDay
17%9%20%37%15%2
270
21st to endDay
12%433%32%17%1
294
February1st to 10thDay
17%8%23%30%18%5%
240
11th to 20thDay
20%8%29%29%13%2
240
21st to endDay
16%7%32%38%7%
198
March1st to 10thDay
18%5%36%31%10%
240
11th to 20thDay
18%335%30%12%2
240
21st to endDay
14%9%34%32%9%2
264
April1st to 10thDay
13%6%34%35%10%1
370
11th to 20thDay
11%8%35%36%9%
412
21st to endDay
12%6%39%32%10%1
420
May1st to 10thDay
13%428%40%13%1
495
11th to 20thDay
19%225%39%12%2
625
21st to endDay
18%222%44%13%2
679
June1st to 10thDay
7%112%50%27%3
630
11th to 20thDay
7%114%47%27%4
630
21st to endDay
5%19%40%36%9%
630
July1st to 10thDay
11%15%32%40%11%
621
11th to 20thDay
4337%49%7%
614
21st to endDay
21432%47%14%
487
August1st to 10thDay
11233%51%13%
447
11th to 20thDay
4227%53%14%
437
21st to endDay
31327%43%21%
495
September1st to 10thDay
11%1225%42%19%
338
11th to 20thDay
6%1121%46%24%
270
21st to endDay
10%1327%43%17%
270
October1st to 10thDay
9%112%33%36%8%
270
11th to 20thDay
19%19%30%35%5%
270
21st to endDay
21%420%30%22%4
297
November1st to 10thDay
22%116%33%23%6%
270
11th to 20thDay
19%416%28%24%9%
270
21st to endDay
19%5%34%27%12%3
270
December1st to 10thDay
19%5%17%30%22%7%
270
11th to 20thDay
16%6%31%28%18%1
270
21st to endDay
20%422%35%18%2
297
January1st to 10thNight
13%323%49%11%1
950
11th to 20thNight
14%5%22%49%9%
760
21st to endNight
15%5%28%45%7%
834
February1st to 10thNight
12%6%28%44%9%
720
11th to 20thNight
16%435%39%7%
704
21st to endNight
11%5%39%44%2
592
March1st to 10thNight
18%6%34%38%5%
720
11th to 20thNight
13%6%34%42%5%
556
21st to endNight
11%7%43%35%5%
594
April1st to 10thNight
8%444%41%3
540
11th to 20thNight
12%6%46%33%3
533
21st to endNight
12%5%47%31%5%
540
May1st to 10thNight
10%6%40%40%4
540
11th to 20thNight
11%236%43%8%
531
21st to endNight
11%233%46%8%
584
June1st to 10thNight
5%123%59%12%
540
11th to 20thNight
3127%56%13%
540
21st to endNight
6%119%52%22%1
540
July1st to 10thNight
10%10%53%25%2
525
11th to 20thNight
38%59%28%1
522
21st to endNight
5%17%59%28%1
591
August1st to 10thNight
2453%38%3
537
11th to 20thNight
5%450%39%3
534
21st to endNight
5%450%37%3
594
September1st to 10thNight
6%346%39%5%
540
11th to 20thNight
11%5%42%39%2
540
21st to endNight
9%17%44%36%2
540
October1st to 10thNight
9%113%49%27%1
540
11th to 20thNight
13%117%46%21%1
540
21st to endNight
10%420%43%21%2
684
November1st to 10thNight
15%216%41%24%1
901
11th to 20thNight
11%320%47%18%2
950
21st to endNight
15%323%44%15%1
950
December1st to 10thNight
15%218%46%17%1
950
11th to 20thNight
18%421%43%13%
950
21st to endNight
15%5%24%45%12%
1045
Page generated at 2024-01-28 04:26:36. Version ac07

Copyright 2024 Attilla Danko


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