Cayuga
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cayuga 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
34%
23023
14%
75098
10%
22975
41%
22975
18%
52314

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
16%
757
11%
2626
5%
757
24%
757
9%
2010
January11th to 20thNight
16%
760
8%
2470
4%
760
21%
760
8%
1975
January21st to endNight
17%
835
11%
2711
4%
835
25%
835
11%
2069
February1st to 10thNight
15%
720
8%
2340
1%
720
23%
720
10%
1840
February11th to 20thNight
20%
700
11%
2275
3%
700
29%
700
12%
1715
February21st to endNight
20%
592
11%
1844
4%
592
29%
592
12%
1405
March1st to 10thNight
26%
720
16%
1980
9%
720
32%
720
18%
1439
March11th to 20thNight
24%
720
18%
1980
8%
720
33%
720
19%
1433
March21st to endNight
30%
792
19%
2178
9%
792
38%
792
21%
1554
April1st to 10thNight
26%
720
14%
1856
5%
720
33%
720
21%
1364
April11th to 20thNight
33%
652
18%
1716
7%
652
38%
652
23%
1218
April21st to endNight
36%
540
18%
1620
7%
540
43%
540
22%
1110
May1st to 10thNight
41%
540
16%
1620
10%
540
46%
540
24%
1084
May11th to 20thNight
45%
431
19%
1493
15%
431
53%
431
23%
931
May21st to endNight
55%
388
17%
1551
19%
388
60%
388
26%
856
June1st to 10thNight
47%
360
15%
1440
14%
360
57%
360
21%
850
June11th to 20thNight
51%
360
16%
1440
19%
360
59%
360
24%
822
June21st to endNight
55%
360
16%
1440
19%
360
63%
360
25%
822
July1st to 10thNight
63%
350
19%
1400
25%
350
68%
350
32%
703
July11th to 20thNight
58%
398
18%
1442
21%
398
63%
398
30%
815
July21st to endNight
61%
591
17%
1672
14%
558
65%
558
34%
995
August1st to 10thNight
66%
537
19%
1600
17%
534
68%
534
35%
946
August11th to 20thNight
62%
534
21%
1598
16%
534
66%
534
34%
954
August21st to endNight
62%
666
22%
1854
14%
666
65%
666
36%
1122
September1st to 10thNight
53%
720
19%
1800
10%
720
56%
720
32%
1197
September11th to 20thNight
61%
720
28%
1934
19%
720
65%
720
39%
1143
September21st to endNight
47%
720
20%
1998
15%
720
51%
720
27%
1347
October1st to 10thNight
41%
720
17%
2160
15%
720
46%
720
25%
1421
October11th to 20thNight
30%
720
14%
2160
9%
720
39%
720
20%
1507
October21st to endNight
25%
792
16%
2376
11%
792
32%
792
16%
1744
November1st to 10thNight
36%
740
21%
2413
14%
740
45%
740
22%
1526
November11th to 20thNight
25%
760
16%
2660
9%
760
36%
760
15%
1826
November21st to endNight
22%
760
10%
2660
6%
760
28%
760
13%
1911
December1st to 10thNight
18%
760
8%
2660
4%
760
23%
760
9%
2048
December11th to 20thNight
14%
759
7%
3259
3%
759
22%
759
7%
2506
December21st to endNight
15%
829
4%
4872
1%
817
22%
817
4%
4106

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
15%9%47%6%45%5%6%7%33%
74801
Night
16%10%47%6%35%5%5%7%34%
75322
TransparencyDay
49%6%13%20%10%1
74518
Night
50%6%12%20%11%1
75139
SeeingDay
18%12%28%24%13%5%
13408
Night
20%10%29%28%12%1
23038

By Month

Percentage Cloud Cover NE (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
17%16%5%10%7%445%5%6%21%
1537
11th to 20thDay
17%17%7%12%7%45%5%45%17%
1710
21st to endDay
14%17%7%13%9%46%5%45%16%
1872
February1st to 10thDay
18%18%5%12%8%46%445%17%
1620
11th to 20thDay
14%14%8%11%9%45%45%423%
1573
21st to endDay
20%14%5%10%7%44445%23%
1409
March1st to 10thDay
16%12%5%10%7%35%447%27%
1977
11th to 20thDay
13%14%6%7%7%35%436%31%
1980
21st to endDay
20%11%47%6%44446%29%
2178
April1st to 10thDay
17%12%6%8%5%4445%6%30%
2103
11th to 20thDay
18%9%47%5%245%5%8%34%
2208
21st to endDay
20%8%37%5%45%5%5%6%33%
2340
May1st to 10thDay
14%10%37%6%45%5%5%6%35%
2340
11th to 20thDay
15%7%37%5%45%46%7%37%
2399
21st to endDay
11%5%25%5%35%6%7%8%43%
2725
June1st to 10thDay
12%6%345%35%5%6%8%41%
2520
11th to 20thDay
12%6%36%5%35%6%6%8%41%
2520
21st to endDay
12%6%25%5%345%6%9%43%
2520
July1st to 10thDay
7%425%5%35%5%7%10%47%
2520
11th to 20thDay
12%6%25%5%46%5%8%10%37%
2466
21st to endDay
9%5%35%6%46%7%8%10%37%
2547
August1st to 10thDay
9%425%5%35%6%9%11%41%
2327
11th to 20thDay
10%5%25%6%47%6%8%10%38%
2303
21st to endDay
11%6%26%5%45%6%5%8%42%
2484
September1st to 10thDay
12%7%35%435%5%6%8%41%
2160
11th to 20thDay
10%5%25%5%445%6%8%46%
2022
21st to endDay
14%6%35%6%45%5%8%9%36%
1962
October1st to 10thDay
17%10%37%5%45%446%36%
1800
11th to 20thDay
19%9%38%7%4445%7%30%
1800
21st to endDay
23%12%48%6%35%45%6%24%
1980
November1st to 10thDay
14%7%46%6%45%5%6%7%35%
1661
11th to 20thDay
14%13%47%6%35%45%8%29%
1520
21st to endDay
21%12%48%5%3446%8%24%
1520
December1st to 10thDay
19%14%5%10%7%445%5%7%19%
1520
11th to 20thDay
19%15%5%8%5%46%5%6%5%21%
1906
21st to endDay
28%19%8%10%7%2433412%
2772
January1st to 10thNight
18%14%5%10%7%45%445%23%
2626
11th to 20thNight
19%17%6%9%7%35%5%5%5%19%
2470
21st to endNight
14%14%8%11%6%35%5%5%6%23%
2711
February1st to 10thNight
17%16%5%9%7%46%45%6%20%
2340
11th to 20thNight
16%12%5%10%7%35%6%5%5%26%
2273
21st to endNight
19%12%6%8%7%45%5%47%24%
1844
March1st to 10thNight
14%9%47%7%45%6%5%6%32%
1970
11th to 20thNight
18%10%5%7%5%34447%33%
1979
21st to endNight
17%9%37%6%3445%6%35%
2178
April1st to 10thNight
18%10%46%7%35%45%6%33%
1856
11th to 20thNight
17%8%46%6%35%45%6%37%
1716
21st to endNight
15%7%37%6%35%5%5%7%36%
1620
May1st to 10thNight
17%8%36%5%35%45%8%37%
1620
11th to 20thNight
14%435%6%35%6%6%6%42%
1492
21st to endNight
11%5%25%5%235%7%9%47%
1550
June1st to 10thNight
10%6%35%5%45%7%7%8%41%
1440
11th to 20thNight
9%5%35%5%45%5%6%8%44%
1440
21st to endNight
10%6%246%35%5%5%8%46%
1440
July1st to 10thNight
5%5%35%434449%55%
1440
11th to 20thNight
10%4244345%6%9%48%
1490
21st to endNight
8%425%5%346%7%8%48%
1771
August1st to 10thNight
7%5%345%446%7%9%47%
1611
11th to 20thNight
9%4345%35%5%6%9%47%
1598
21st to endNight
8%425%5%26%5%6%9%48%
1854
September1st to 10thNight
13%7%25%5%3345%8%44%
1800
11th to 20thNight
10%42442445%6%54%
1934
21st to endNight
15%6%36%6%345%5%7%41%
1998
October1st to 10thNight
14%7%36%6%3445%7%42%
2160
11th to 20thNight
18%9%36%5%345%6%6%34%
2160
21st to endNight
22%9%46%6%35%5%5%5%30%
2376
November1st to 10thNight
15%7%35%5%35%45%8%41%
2413
11th to 20thNight
16%10%46%6%36%5%6%8%31%
2660
21st to endNight
20%11%47%6%35%5%5%6%29%
2660
December1st to 10thNight
20%14%5%9%6%445%6%6%22%
2660
11th to 20thNight
16%17%5%9%6%35%5%5%6%23%
3288
21st to endNight
27%18%6%8%6%44445%13%
4884

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
63%5%11%14%7%
1538
11th to 20thDay
69%5%10%13%3
1710
21st to endDay
71%5%9%11%5%
1872
February1st to 10thDay
70%49%12%4
1620
11th to 20thDay
64%49%15%7%1
1582
21st to endDay
63%5%9%15%7%1
1409
March1st to 10thDay
56%5%13%18%6%1
1980
11th to 20thDay
54%5%10%19%10%2
1980
21st to endDay
57%47%19%11%2
2178
April1st to 10thDay
54%5%11%18%12%1
2103
11th to 20thDay
47%5%12%20%13%2
2208
21st to endDay
50%6%11%19%12%2
2340
May1st to 10thDay
47%6%11%23%12%2
2340
11th to 20thDay
46%6%13%21%13%2
2403
21st to endDay
36%7%17%24%15%1
2725
June1st to 10thDay
39%6%12%25%15%2
2520
11th to 20thDay
38%7%14%24%14%1
2520
21st to endDay
36%8%14%26%15%1
2520
July1st to 10thDay
31%8%13%27%19%3
2450
11th to 20thDay
37%8%17%25%12%1
2391
21st to endDay
37%9%15%23%13%1
2405
August1st to 10thDay
33%7%19%28%12%1
2314
11th to 20thDay
37%8%18%26%10%1
2303
21st to endDay
38%5%14%28%13%1
2484
September1st to 10thDay
39%7%16%25%12%1
2160
11th to 20thDay
35%6%14%29%16%1
2022
21st to endDay
42%7%15%25%10%1
1962
October1st to 10thDay
49%5%14%19%12%1
1800
11th to 20thDay
52%6%14%19%8%1
1800
21st to endDay
61%5%12%16%6%1
1980
November1st to 10thDay
46%7%14%22%9%2
1661
11th to 20thDay
53%7%15%16%10%1
1520
21st to endDay
58%5%17%14%5%
1520
December1st to 10thDay
63%7%14%13%3
1520
11th to 20thDay
63%6%15%10%5%
1906
21st to endDay
77%5%8%8%2
2772
January1st to 10thNight
63%411%15%7%
2626
11th to 20thNight
66%6%12%11%41
2470
21st to endNight
61%5%11%15%6%1
2711
February1st to 10thNight
64%5%12%13%5%1
2340
11th to 20thNight
59%5%11%17%7%1
2275
21st to endNight
60%5%11%16%7%
1844
March1st to 10thNight
52%6%11%21%9%2
1980
11th to 20thNight
52%5%9%20%12%2
1980
21st to endNight
50%5%7%21%14%3
2178
April1st to 10thNight
52%5%10%19%13%1
1856
11th to 20thNight
49%5%8%20%16%3
1716
21st to endNight
47%6%10%19%15%3
1620
May1st to 10thNight
47%410%22%14%4
1620
11th to 20thNight
41%6%11%25%13%4
1493
21st to endNight
34%6%13%26%18%3
1551
June1st to 10thNight
39%7%10%24%17%2
1440
11th to 20thNight
37%6%12%25%18%2
1440
21st to endNight
37%6%13%25%17%2
1440
July1st to 10thNight
28%5%12%27%24%4
1400
11th to 20thNight
33%6%12%29%18%2
1442
21st to endNight
31%8%15%25%18%3
1672
August1st to 10thNight
31%7%16%30%14%2
1600
11th to 20thNight
32%7%15%32%13%1
1598
21st to endNight
32%6%14%29%16%2
1854
September1st to 10thNight
39%5%13%25%16%2
1800
11th to 20thNight
30%6%11%35%18%1
1934
21st to endNight
42%6%12%24%14%1
1998
October1st to 10thNight
43%5%12%24%15%1
2160
11th to 20thNight
50%5%14%22%10%1
2160
21st to endNight
55%5%11%18%10%1
2376
November1st to 10thNight
41%6%14%25%13%1
2413
11th to 20thNight
50%5%13%20%10%1
2660
21st to endNight
56%5%18%16%5%
2660
December1st to 10thNight
62%6%14%14%4
2660
11th to 20thNight
62%7%13%14%5%
3288
21st to endNight
74%6%11%8%2
4884

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
25%22%28%14%9%1
190
11th to 20thDay
26%24%34%10%5%1
270
21st to endDay
22%24%31%18%41
294
February1st to 10thDay
26%19%43%11%1
240
11th to 20thDay
23%24%41%12%
240
21st to endDay
30%27%30%12%
206
March1st to 10thDay
22%14%35%21%8%
420
11th to 20thDay
23%15%39%18%6%
420
21st to endDay
29%12%31%18%9%1
462
April1st to 10thDay
19%17%32%24%8%1
420
11th to 20thDay
23%16%29%19%9%4
412
21st to endDay
24%10%32%22%9%3
420
May1st to 10thDay
24%11%28%23%9%5%
423
11th to 20thDay
16%9%28%28%15%5%
447
21st to endDay
13%7%24%29%19%8%
485
June1st to 10thDay
12%9%32%33%12%3
450
11th to 20thDay
14%9%23%31%20%4
450
21st to endDay
16%6%26%33%14%5%
450
July1st to 10thDay
8%418%33%27%10%
445
11th to 20thDay
14%6%23%28%19%11%
444
21st to endDay
10%427%34%18%7%
488
August1st to 10thDay
9%420%30%23%13%
446
11th to 20thDay
10%5%23%29%20%12%
439
21st to endDay
12%5%23%30%19%11%
495
September1st to 10thDay
14%6%23%26%20%11%
450
11th to 20thDay
10%6%20%24%25%16%
450
21st to endDay
16%10%27%24%15%8%
450
October1st to 10thDay
20%13%23%22%17%6%
450
11th to 20thDay
20%16%33%21%7%3
450
21st to endDay
29%15%28%19%9%
495
November1st to 10thDay
19%22%32%16%8%3
289
11th to 20thDay
23%25%24%18%7%2
180
21st to endDay
27%19%36%15%31
180
December1st to 10thDay
27%19%32%17%41
180
11th to 20thDay
26%25%32%14%3
180
21st to endDay
27%21%35%14%3
198
January1st to 10thNight
25%17%34%18%6%1
760
11th to 20thNight
27%17%33%18%5%
760
21st to endNight
21%13%37%24%5%
835
February1st to 10thNight
26%18%34%21%2
720
11th to 20thNight
22%15%34%24%4
703
21st to endNight
24%16%33%24%2
592
March1st to 10thNight
20%11%34%29%7%
720
11th to 20thNight
24%11%35%23%7%1
720
21st to endNight
21%8%34%27%9%1
792
April1st to 10thNight
23%11%33%30%4
720
11th to 20thNight
20%11%32%27%10%1
652
21st to endNight
19%5%32%33%10%
540
May1st to 10thNight
20%427%31%16%2
540
11th to 20thNight
16%427%39%13%1
431
21st to endNight
13%6%21%37%22%2
389
June1st to 10thNight
11%432%37%15%1
360
11th to 20thNight
13%426%38%18%1
360
21st to endNight
13%421%46%17%
360
July1st to 10thNight
6%320%45%25%2
350
11th to 20thNight
11%422%41%20%2
398
21st to endNight
10%220%45%21%2
591
August1st to 10thNight
8%415%41%31%3
537
11th to 20thNight
10%217%34%34%3
534
21st to endNight
9%318%37%30%3
666
September1st to 10thNight
15%5%18%32%24%5%
720
11th to 20thNight
13%317%33%29%5%
720
21st to endNight
17%6%22%30%21%5%
720
October1st to 10thNight
18%7%26%28%18%3
720
11th to 20thNight
22%13%29%26%9%1
720
21st to endNight
27%11%32%25%6%
792
November1st to 10thNight
20%12%28%27%12%2
740
11th to 20thNight
22%13%33%21%10%1
760
21st to endNight
25%13%34%21%7%
760
December1st to 10thNight
28%17%31%18%6%
760
11th to 20thNight
23%18%36%19%5%
760
21st to endNight
32%13%31%22%2
836
Page generated at 2024-01-28 05:26:36. Version ac07

Copyright 2024 Attilla Danko


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