Turtle Beach Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Turtle Beach Observatory clear sky chart from 2005-11-06 to 2024-02-25.

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
47%
23986
23%
79449
16%
23877
54%
23877
28%
47358

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
26%
946
28%
3981
8%
926
36%
926
19%
2263
January11th to 20thNight
29%
949
26%
3941
9%
930
38%
930
19%
2260
January21st to endNight
26%
1039
17%
4465
7%
1023
36%
1023
17%
2878
February1st to 10thNight
25%
950
22%
2470
6%
950
34%
950
25%
1674
February11th to 20thNight
24%
746
20%
2222
8%
743
34%
743
23%
1441
February21st to endNight
19%
458
23%
1678
10%
458
33%
458
16%
1105
March1st to 10thNight
32%
540
24%
1980
12%
540
45%
540
21%
1214
March11th to 20thNight
28%
540
21%
1980
12%
540
40%
540
19%
1267
March21st to endNight
34%
594
22%
2178
16%
594
44%
594
25%
1269
April1st to 10thNight
31%
540
24%
1894
15%
540
44%
540
24%
1136
April11th to 20thNight
33%
533
23%
1775
15%
533
45%
533
24%
1086
April21st to endNight
37%
540
25%
1800
15%
540
51%
540
28%
1052
May1st to 10thNight
40%
540
20%
1800
16%
540
50%
540
27%
1075
May11th to 20thNight
50%
531
23%
1667
21%
531
57%
531
33%
982
May21st to endNight
60%
584
24%
1745
21%
582
67%
582
35%
1014
June1st to 10thNight
68%
540
17%
1620
18%
540
71%
540
34%
954
June11th to 20thNight
74%
540
20%
1620
20%
540
78%
540
46%
843
June21st to endNight
75%
540
21%
1620
22%
540
78%
540
37%
937
July1st to 10thNight
75%
525
14%
1575
18%
525
75%
525
33%
948
July11th to 20thNight
79%
522
19%
1566
21%
522
81%
522
38%
896
July21st to endNight
78%
591
18%
1673
21%
558
80%
558
36%
973
August1st to 10thNight
84%
537
22%
1601
25%
534
86%
534
49%
811
August11th to 20thNight
78%
534
21%
1774
24%
534
80%
534
33%
1011
August21st to endNight
71%
594
18%
1980
21%
594
72%
594
27%
1222
September1st to 10thNight
77%
540
22%
1800
24%
540
77%
540
33%
1041
September11th to 20thNight
67%
540
22%
1939
24%
540
68%
540
25%
1183
September21st to endNight
70%
558
30%
1998
31%
558
72%
558
35%
1045
October1st to 10thNight
70%
720
30%
2160
25%
720
73%
720
44%
1142
October11th to 20thNight
57%
720
34%
2160
23%
720
65%
720
38%
1194
October21st to endNight
50%
792
33%
2376
23%
792
58%
792
37%
1327
November1st to 10thNight
51%
740
30%
2220
22%
740
59%
740
37%
1266
November11th to 20thNight
45%
760
29%
2280
20%
760
52%
760
33%
1315
November21st to endNight
37%
760
28%
2280
16%
760
46%
760
26%
1442
December1st to 10thNight
34%
916
26%
2436
12%
916
44%
916
27%
1635
December11th to 20thNight
29%
948
24%
2867
10%
948
38%
948
23%
1870
December21st to endNight
30%
1039
14%
4328
9%
1026
38%
1026
17%
2587

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
13%6%35%5%35%5%5%7%42%
78952
Night
13%6%2443445%7%48%
80401
TransparencyDay
40%7%11%19%18%6%
78676
Night
36%6%11%19%20%8%
80197
SeeingDay
13%8%20%25%25%10%
14020
Night
15%8%25%31%19%3
24005

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
20%9%35%424345%41%
2847
11th to 20thDay
21%5%34322335%48%
2850
21st to endDay
22%9%25%423345%41%
3135
February1st to 10thDay
20%9%45%5%34345%39%
1710
11th to 20thDay
21%9%35%434335%41%
1859
21st to endDay
20%8%36%5%33445%38%
1672
March1st to 10thDay
20%8%36%423446%39%
1980
11th to 20thDay
16%8%36%5%3445%8%38%
1980
21st to endDay
14%7%26%6%44445%44%
2178
April1st to 10thDay
12%6%37%5%35%5%6%7%41%
2065
11th to 20thDay
16%6%36%5%35%45%8%40%
2134
21st to endDay
10%5%36%5%45%5%5%7%45%
2160
May1st to 10thDay
11%6%36%6%45%5%6%9%39%
2160
11th to 20thDay
11%6%25%5%445%6%8%43%
2224
21st to endDay
8%5%35%7%48%6%8%10%36%
2531
June1st to 10thDay
7%426%6%5%7%7%8%11%38%
2340
11th to 20thDay
5%435%6%5%7%6%7%11%41%
2340
21st to endDay
6%5%36%7%5%7%6%8%10%36%
2340
July1st to 10thDay
9%5%26%6%47%7%8%10%36%
2340
11th to 20thDay
6%426%7%46%7%8%11%39%
2340
21st to endDay
6%426%7%47%8%8%10%37%
2546
August1st to 10thDay
3325%6%47%7%8%11%45%
2328
11th to 20thDay
5%5%25%6%46%7%8%10%42%
2125
21st to endDay
11%426%7%5%6%7%7%10%36%
2376
September1st to 10thDay
9%436%7%46%6%5%8%44%
2160
11th to 20thDay
13%5%346%45%6%7%7%40%
2016
21st to endDay
9%4145%35%5%48%52%
1941
October1st to 10thDay
7%414434445%61%
1800
11th to 20thDay
12%5%2442345%6%54%
1800
21st to endDay
15%5%24424336%52%
1980
November1st to 10thDay
10%5%25%335%35%6%52%
1858
11th to 20thDay
11%6%36%42335%6%52%
1900
21st to endDay
17%6%26%5%24435%44%
1900
December1st to 10thDay
16%9%35%434445%44%
1741
11th to 20thDay
16%11%36%6%3445%5%39%
2161
21st to endDay
16%10%36%5%24445%41%
3135
January1st to 10thNight
15%8%35%433345%49%
4108
11th to 20thNight
19%7%2432323450%
4120
21st to endNight
24%10%25%423335%40%
4532
February1st to 10thNight
17%7%36%425%347%42%
2470
11th to 20thNight
21%9%24423345%43%
2221
21st to endNight
22%8%35%5%23345%40%
1678
March1st to 10thNight
20%7%24433447%43%
1980
11th to 20thNight
16%7%25%5%35%447%41%
1980
21st to endNight
13%6%35%424447%48%
2178
April1st to 10thNight
11%5%345%35%5%6%7%46%
1894
11th to 20thNight
14%5%25%5%345%47%45%
1775
21st to endNight
10%435%5%35%45%5%51%
1800
May1st to 10thNight
11%6%35%43446%8%45%
1800
11th to 20thNight
10%425%5%3445%7%50%
1666
21st to endNight
7%5%25%5%245%6%12%48%
1745
June1st to 10thNight
6%325%6%35%5%7%11%48%
1620
11th to 20thNight
33233246%5%11%58%
1620
21st to endNight
7%413335%6%9%11%49%
1620
July1st to 10thNight
5%4345%36%5%7%14%43%
1620
11th to 20thNight
4324435%6%7%12%49%
1620
21st to endNight
43245%35%6%7%13%48%
1772
August1st to 10thNight
221333337%14%59%
1611
11th to 20thNight
5%323445%7%8%12%47%
1774
21st to endNight
10%4246%36%5%7%10%43%
1980
September1st to 10thNight
6%425%5%35%5%6%8%50%
1800
11th to 20thNight
11%5%36%5%45%45%8%45%
1939
21st to endNight
9%5%2432345%6%57%
1998
October1st to 10thNight
6%31342445%7%59%
2160
11th to 20thNight
9%5%23423446%57%
2160
21st to endNight
13%5%2331334458%
2376
November1st to 10thNight
11%424424345%57%
2220
11th to 20thNight
11%5%245%34346%53%
2280
21st to endNight
15%7%35%5%33346%45%
2280
December1st to 10thNight
19%8%34423346%43%
2436
11th to 20thNight
16%9%35%433435%45%
3036
21st to endNight
16%9%25%423445%44%
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
45%5%5%18%22%5%
2848
11th to 20thDay
39%45%21%25%5%
2850
21st to endDay
47%3416%21%9%
3135
February1st to 10thDay
49%36%15%17%10%
1710
11th to 20thDay
48%46%15%18%9%
1868
21st to endDay
49%5%6%12%17%11%
1672
March1st to 10thDay
47%5%7%15%17%9%
1980
11th to 20thDay
45%5%9%14%21%6%
1980
21st to endDay
43%48%15%24%5%
2178
April1st to 10thDay
42%6%9%19%16%7%
2065
11th to 20thDay
44%5%10%17%16%9%
2134
21st to endDay
39%6%10%19%21%6%
2160
May1st to 10thDay
41%8%10%20%15%6%
2160
11th to 20thDay
38%7%12%26%15%3
2228
21st to endDay
39%10%14%24%13%1
2531
June1st to 10thDay
37%10%16%21%15%1
2340
11th to 20thDay
34%8%16%25%15%1
2340
21st to endDay
39%10%17%21%12%2
2340
July1st to 10thDay
40%11%18%23%7%1
2276
11th to 20thDay
35%11%19%24%10%1
2271
21st to endDay
37%12%21%23%8%1
2405
August1st to 10thDay
29%10%21%28%11%1
2314
11th to 20thDay
33%10%20%25%10%1
2125
21st to endDay
40%10%18%21%10%1
2376
September1st to 10thDay
37%8%14%20%14%7%
2160
11th to 20thDay
41%7%14%15%17%6%
2016
21st to endDay
32%6%10%22%21%9%
1941
October1st to 10thDay
26%5%10%22%25%13%
1800
11th to 20thDay
31%47%18%26%14%
1800
21st to endDay
35%5%417%26%14%
1980
November1st to 10thDay
33%6%10%17%25%10%
1858
11th to 20thDay
35%47%15%27%12%
1900
21st to endDay
44%46%17%21%8%
1900
December1st to 10thDay
42%5%10%17%18%8%
1741
11th to 20thDay
47%45%14%23%7%
2159
21st to endDay
45%45%13%26%6%
3135
January1st to 10thNight
39%45%19%27%6%
4108
11th to 20thNight
40%35%20%23%9%
4120
21st to endNight
48%36%16%18%8%
4532
February1st to 10thNight
43%5%7%17%17%11%
2470
11th to 20thNight
44%37%15%20%10%
2222
21st to endNight
49%46%12%15%14%
1678
March1st to 10thNight
43%49%15%19%10%
1980
11th to 20thNight
44%6%9%14%20%7%
1980
21st to endNight
37%6%11%16%24%7%
2178
April1st to 10thNight
37%7%9%21%17%9%
1894
11th to 20thNight
39%5%10%18%16%11%
1775
21st to endNight
34%7%9%19%24%6%
1800
May1st to 10thNight
36%6%12%19%19%7%
1800
11th to 20thNight
32%7%11%25%21%3
1667
21st to endNight
29%8%18%26%18%1
1746
June1st to 10thNight
28%10%17%25%18%1
1620
11th to 20thNight
20%8%20%34%15%3
1620
21st to endNight
26%10%20%27%16%1
1620
July1st to 10thNight
29%12%28%23%8%1
1575
11th to 20thNight
24%11%29%24%10%1
1566
21st to endNight
24%12%27%24%11%1
1673
August1st to 10thNight
17%8%29%32%13%1
1601
11th to 20thNight
27%11%23%25%13%2
1774
21st to endNight
35%9%20%21%11%3
1980
September1st to 10thNight
29%10%18%21%14%8%
1800
11th to 20thNight
36%9%12%19%16%8%
1939
21st to endNight
28%6%11%22%21%12%
1998
October1st to 10thNight
24%5%12%22%22%15%
2160
11th to 20thNight
28%5%7%17%27%15%
2160
21st to endNight
30%37%17%25%17%
2376
November1st to 10thNight
30%5%9%18%26%12%
2220
11th to 20thNight
33%49%16%25%13%
2280
21st to endNight
42%47%16%23%9%
2280
December1st to 10thNight
42%5%8%18%19%7%
2436
11th to 20thNight
42%46%12%23%12%
3037
21st to endNight
42%46%17%24%6%
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
24%16%39%16%5%
270
11th to 20thDay
24%17%31%23%4
270
21st to endDay
22%22%33%19%3
297
February1st to 10thDay
26%16%34%20%31
270
11th to 20thDay
33%17%32%17%1
270
21st to endDay
27%28%32%12%1
210
March1st to 10thDay
26%18%33%18%6%
240
11th to 20thDay
18%23%36%18%4
240
21st to endDay
17%17%39%21%5%
264
April1st to 10thDay
15%15%38%24%8%
325
11th to 20thDay
22%15%26%24%11%1
412
21st to endDay
13%13%31%31%10%2
420
May1st to 10thDay
15%9%33%28%13%1
423
11th to 20thDay
14%422%35%20%5%
547
21st to endDay
9%422%37%21%7%
679
June1st to 10thDay
7%314%32%32%12%
630
11th to 20thDay
7%213%34%36%8%
630
21st to endDay
10%111%24%40%15%
630
July1st to 10thDay
7%27%25%44%15%
621
11th to 20thDay
426%22%45%22%
618
21st to endDay
7%5%25%47%16%
684
August1st to 10thDay
416%18%49%22%
626
11th to 20thDay
5%2217%50%23%
439
21st to endDay
10%27%17%33%29%
495
September1st to 10thDay
8%16%18%44%23%
450
11th to 20thDay
10%310%21%37%20%
306
21st to endDay
14%36%26%38%14%
270
October1st to 10thDay
8%216%36%28%10%
270
11th to 20thDay
10%7%26%27%23%7%
270
21st to endDay
22%13%23%22%15%5%
297
November1st to 10thDay
13%8%24%33%18%4
270
11th to 20thDay
14%12%33%27%12%2
270
21st to endDay
21%15%34%21%6%2
270
December1st to 10thDay
19%9%37%23%9%4
270
11th to 20thDay
22%13%33%25%6%
270
21st to endDay
23%15%35%22%31
297
January1st to 10thNight
21%12%37%24%6%
950
11th to 20thNight
23%14%30%25%7%
950
21st to endNight
23%12%35%27%3
1045
February1st to 10thNight
21%15%35%25%3
950
11th to 20thNight
25%14%33%23%4
746
21st to endNight
26%16%37%20%1
458
March1st to 10thNight
23%11%32%29%6%
540
11th to 20thNight
19%12%37%26%5%1
540
21st to endNight
15%11%38%28%8%
594
April1st to 10thNight
13%10%43%28%6%
540
11th to 20thNight
16%11%35%25%13%
533
21st to endNight
12%10%38%28%11%1
540
May1st to 10thNight
12%9%32%34%11%1
540
11th to 20thNight
11%5%27%35%18%3
531
21st to endNight
7%323%40%22%5%
584
June1st to 10thNight
6%114%40%35%4
540
11th to 20thNight
4314%49%28%3
540
21st to endNight
8%110%37%36%8%
540
July1st to 10thNight
427%38%41%8%
525
11th to 20thNight
317%35%43%10%
522
21st to endNight
416%37%43%9%
591
August1st to 10thNight
315%36%47%8%
537
11th to 20thNight
5%7%34%46%9%
534
21st to endNight
10%16%28%43%12%
594
September1st to 10thNight
6%2432%46%9%
540
11th to 20thNight
12%110%28%40%8%
540
21st to endNight
10%311%33%35%8%
558
October1st to 10thNight
8%215%37%34%5%
720
11th to 20thNight
11%7%21%38%20%3
720
21st to endNight
15%7%23%33%19%3
792
November1st to 10thNight
12%5%27%34%21%1
740
11th to 20thNight
13%9%28%35%14%
760
21st to endNight
19%9%31%28%12%1
760
December1st to 10thNight
22%13%28%28%9%
916
11th to 20thNight
24%11%31%29%5%
950
21st to endNight
23%12%31%28%6%
1045
Page generated at 2024-02-22 05:05:41. Version ac07

Copyright 2024 Attilla Danko


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