Onondaga Cave State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Onondaga Cave State Park clear sky chart from 2005-11-06 to 2024-01-11.

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
36%
24360
21%
74682
12%
24297
45%
24297
25%
47269

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%
950
19%
2625
5%
946
28%
946
19%
1791
January11th to 20thNight
17%
905
20%
2353
6%
905
27%
905
19%
1683
January21st to endNight
17%
990
20%
2574
4%
990
28%
990
21%
1806
February1st to 10thNight
16%
900
16%
2340
3%
900
23%
900
19%
1700
February11th to 20thNight
15%
753
19%
2149
5%
750
24%
750
20%
1435
February21st to endNight
16%
592
20%
1776
4%
592
29%
592
17%
1197
March1st to 10thNight
18%
648
20%
2088
6%
648
30%
648
20%
1345
March11th to 20thNight
22%
540
18%
1980
9%
540
34%
540
16%
1326
March21st to endNight
19%
594
11%
2102
6%
594
27%
594
13%
1479
April1st to 10thNight
27%
540
23%
1800
11%
540
43%
540
26%
1029
April11th to 20thNight
29%
533
21%
1775
14%
533
41%
533
23%
1085
April21st to endNight
23%
540
19%
1800
9%
540
38%
540
20%
1176
May1st to 10thNight
35%
540
16%
1789
11%
540
43%
540
24%
1119
May11th to 20thNight
42%
531
20%
1446
15%
531
47%
531
29%
944
May21st to endNight
46%
584
17%
1551
10%
582
52%
582
27%
1069
June1st to 10thNight
61%
540
18%
1440
14%
540
64%
540
37%
879
June11th to 20thNight
60%
540
26%
1440
17%
540
64%
540
44%
810
June21st to endNight
63%
540
26%
1440
16%
540
68%
540
48%
792
July1st to 10thNight
68%
525
18%
1400
14%
525
69%
525
40%
840
July11th to 20thNight
71%
522
23%
1429
19%
522
74%
522
46%
781
July21st to endNight
67%
591
24%
1673
22%
558
73%
558
37%
964
August1st to 10thNight
70%
537
22%
1601
22%
534
72%
534
37%
918
August11th to 20thNight
68%
534
23%
1751
26%
534
72%
534
37%
951
August21st to endNight
69%
594
25%
1980
28%
594
72%
594
38%
1036
September1st to 10thNight
62%
540
25%
1800
26%
540
65%
540
33%
1016
September11th to 20thNight
65%
540
33%
1800
32%
540
70%
540
35%
975
September21st to endNight
54%
688
30%
2008
21%
688
61%
688
38%
1137
October1st to 10thNight
53%
720
28%
2160
20%
720
60%
720
43%
1138
October11th to 20thNight
33%
720
30%
2160
15%
720
47%
720
31%
1264
October21st to endNight
28%
792
24%
2376
11%
792
40%
792
25%
1487
November1st to 10thNight
35%
740
29%
2355
17%
740
50%
740
34%
1290
November11th to 20thNight
28%
760
27%
2470
14%
760
44%
760
25%
1463
November21st to endNight
24%
855
21%
2565
10%
855
36%
855
24%
1650
December1st to 10thNight
22%
950
19%
2660
6%
950
33%
950
22%
1822
December11th to 20thNight
23%
949
20%
3162
8%
948
33%
948
19%
2122
December21st to endNight
17%
1043
11%
4864
5%
1026
29%
1026
9%
3750

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%7%35%5%345%5%7%43%
74696
Night
13%8%35%5%3445%7%45%
75014
TransparencyDay
40%7%12%23%16%3
74409
Night
39%6%11%23%17%3
74822
SeeingDay
17%12%27%25%15%4
14424
Night
17%12%30%27%12%1
24363

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%10%5%8%5%23446%41%
1536
11th to 20thDay
14%12%48%4345%46%36%
1620
21st to endDay
14%11%36%5%3335%7%41%
1782
February1st to 10thDay
15%10%5%8%5%44446%35%
1620
11th to 20thDay
15%9%46%6%345%5%6%37%
1696
21st to endDay
14%12%36%6%245%47%37%
1480
March1st to 10thDay
14%10%46%5%23346%43%
1886
11th to 20thDay
20%10%45%5%35%435%37%
1980
21st to endDay
20%11%5%8%6%35%5%46%29%
2253
April1st to 10thDay
11%6%25%5%345%6%8%45%
2160
11th to 20thDay
18%8%245%34446%40%
2134
21st to endDay
20%7%36%5%34447%36%
2160
May1st to 10thDay
19%6%35%5%35%5%6%8%36%
2168
11th to 20thDay
17%5%25%435%45%8%42%
2447
21st to endDay
11%5%37%7%46%6%6%8%36%
2725
June1st to 10thDay
9%5%25%5%36%6%6%9%45%
2520
11th to 20thDay
8%324435%5%6%10%48%
2520
21st to endDay
6%2245%36%6%8%11%48%
2520
July1st to 10thDay
11%5%245%45%6%7%10%41%
2520
11th to 20thDay
43245%45%6%6%9%52%
2479
21st to endDay
9%436%6%35%5%7%9%43%
2546
August1st to 10thDay
9%325%6%46%5%7%10%42%
2328
11th to 20thDay
9%436%6%5%5%6%6%8%42%
2147
21st to endDay
9%5%245%345%5%8%49%
2376
September1st to 10thDay
14%5%235%245%5%9%48%
2160
11th to 20thDay
10%5%25%43445%7%50%
2160
21st to endDay
8%5%344245%5%7%54%
1929
October1st to 10thDay
10%5%245%24346%55%
1800
11th to 20thDay
15%6%34323336%52%
1800
21st to endDay
18%8%34423445%46%
1980
November1st to 10thDay
12%6%15%334445%55%
1722
11th to 20thDay
14%7%3443435%7%47%
1710
21st to endDay
15%10%36%423446%45%
1611
December1st to 10thDay
14%11%35%42435%7%41%
1520
11th to 20thDay
14%11%5%6%5%34346%39%
1918
21st to endDay
15%15%6%7%6%34446%28%
2783
January1st to 10thNight
13%9%47%6%35%345%41%
2625
11th to 20thNight
15%10%5%8%5%34346%37%
2353
21st to endNight
13%11%46%6%345%5%5%39%
2574
February1st to 10thNight
17%11%5%7%434345%37%
2340
11th to 20thNight
14%8%5%7%5%33346%42%
2148
21st to endNight
18%10%38%5%2435%5%38%
1776
March1st to 10thNight
16%10%35%5%24335%43%
2088
11th to 20thNight
20%8%35%5%35%5%45%38%
1980
21st to endNight
20%11%35%6%3445%6%31%
2102
April1st to 10thNight
10%7%35%423449%49%
1800
11th to 20thNight
14%9%245%245%46%45%
1775
21st to endNight
20%6%35%5%3435%6%41%
1800
May1st to 10thNight
17%5%25%43445%6%46%
1789
11th to 20thNight
16%7%34334347%46%
1445
21st to endNight
10%6%36%6%446%6%9%41%
1551
June1st to 10thNight
8%425%5%4446%9%49%
1440
11th to 20thNight
7%3233245%6%11%55%
1440
21st to endNight
42133445%6%10%59%
1440
July1st to 10thNight
9%3245%335%6%10%51%
1440
11th to 20thNight
5%3234325%6%9%58%
1477
21st to endNight
6%4245%35%6%6%10%51%
1772
August1st to 10thNight
6%3245%345%6%10%51%
1611
11th to 20thNight
6%325%5%236%6%9%54%
1751
21st to endNight
7%32443445%8%56%
1980
September1st to 10thNight
12%6%2442335%6%53%
1800
11th to 20thNight
9%4245%235%5%8%54%
1800
21st to endNight
9%424334446%57%
2008
October1st to 10thNight
8%314423348%59%
2160
11th to 20thNight
16%5%14423346%52%
2160
21st to endNight
20%7%24323235%48%
2376
November1st to 10thNight
12%5%2432235%5%57%
2355
11th to 20thNight
14%7%345%23347%49%
2470
21st to endNight
17%9%35%433346%45%
2565
December1st to 10thNight
16%11%45%5%2345%7%38%
2660
11th to 20thNight
15%10%46%5%33445%41%
3279
21st to endNight
16%18%5%8%6%35%5%45%24%
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
44%5%12%21%16%3
1537
11th to 20thDay
50%5%9%25%10%1
1620
21st to endDay
44%412%25%12%2
1782
February1st to 10thDay
52%49%22%12%1
1620
11th to 20thDay
48%5%11%19%13%4
1706
21st to endDay
47%5%8%23%12%5%
1480
March1st to 10thDay
44%5%9%21%17%5%
1886
11th to 20thDay
52%5%10%17%13%3
1980
21st to endDay
57%6%11%16%9%1
2253
April1st to 10thDay
35%7%13%25%19%1
2160
11th to 20thDay
45%5%11%21%15%3
2134
21st to endDay
48%6%11%21%12%1
2160
May1st to 10thDay
46%7%13%22%11%1
2168
11th to 20thDay
40%8%12%23%15%2
2451
21st to endDay
43%9%15%19%13%1
2725
June1st to 10thDay
34%9%14%26%16%1
2520
11th to 20thDay
29%8%14%26%19%4
2520
21st to endDay
27%9%18%26%15%5%
2520
July1st to 10thDay
34%9%16%25%12%4
2451
11th to 20thDay
27%9%17%26%18%4
2404
21st to endDay
36%8%14%29%12%1
2405
August1st to 10thDay
35%10%16%23%15%1
2314
11th to 20thDay
38%9%12%26%14%1
2147
21st to endDay
33%7%15%23%17%6%
2376
September1st to 10thDay
34%7%12%27%16%4
2160
11th to 20thDay
33%6%8%26%25%2
2160
21st to endDay
30%6%9%28%24%3
1929
October1st to 10thDay
30%6%10%25%26%4
1800
11th to 20thDay
35%48%24%22%6%
1800
21st to endDay
40%5%8%25%17%4
1980
November1st to 10thDay
34%411%24%22%6%
1722
11th to 20thDay
38%39%23%22%5%
1710
21st to endDay
42%49%26%17%1
1611
December1st to 10thDay
43%6%11%27%12%2
1520
11th to 20thDay
47%5%9%19%20%1
1915
21st to endDay
56%7%11%15%10%2
2783
January1st to 10thNight
45%5%9%21%17%2
2625
11th to 20thNight
49%5%11%22%12%1
2353
21st to endNight
47%5%12%22%13%1
2574
February1st to 10thNight
51%410%20%13%2
2340
11th to 20thNight
44%5%10%22%16%3
2149
21st to endNight
48%410%21%14%4
1776
March1st to 10thNight
45%39%20%17%5%
2088
11th to 20thNight
49%6%9%21%13%3
1980
21st to endNight
53%6%12%19%9%1
2102
April1st to 10thNight
33%6%12%27%19%2
1800
11th to 20thNight
39%6%11%23%15%5%
1775
21st to endNight
45%6%8%24%16%1
1800
May1st to 10thNight
39%6%14%22%17%2
1789
11th to 20thNight
39%6%14%23%16%2
1446
21st to endNight
39%11%14%19%15%3
1552
June1st to 10thNight
30%8%16%26%18%2
1440
11th to 20thNight
23%8%15%28%22%4
1440
21st to endNight
20%8%17%29%19%6%
1440
July1st to 10thNight
28%7%19%25%16%4
1400
11th to 20thNight
22%7%17%28%22%4
1429
21st to endNight
26%10%13%32%17%2
1673
August1st to 10thNight
26%10%18%30%14%2
1601
11th to 20thNight
24%9%16%29%20%2
1751
21st to endNight
26%6%15%26%22%5%
1980
September1st to 10thNight
32%5%10%26%20%6%
1800
11th to 20thNight
29%6%11%25%27%2
1800
21st to endNight
28%6%10%24%29%4
2008
October1st to 10thNight
24%5%13%26%28%5%
2160
11th to 20thNight
34%48%26%22%6%
2160
21st to endNight
40%48%23%21%5%
2376
November1st to 10thNight
30%412%27%22%6%
2355
11th to 20thNight
37%48%23%23%5%
2470
21st to endNight
43%49%24%18%2
2565
December1st to 10thNight
46%5%11%23%14%2
2660
11th to 20thNight
46%5%9%23%15%1
3281
21st to endNight
60%7%9%13%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
24%25%34%16%2
270
11th to 20thDay
33%18%38%12%
240
21st to endDay
20%31%35%11%2
264
February1st to 10thDay
27%26%34%13%1
240
11th to 20thDay
29%28%30%10%21
240
21st to endDay
30%25%33%10%1
198
March1st to 10thDay
21%30%40%9%1
240
11th to 20thDay
34%20%30%13%31
240
21st to endDay
34%20%32%13%1
339
April1st to 10thDay
19%18%38%18%6%
420
11th to 20thDay
27%16%29%20%6%1
412
21st to endDay
23%17%34%20%41
420
May1st to 10thDay
23%16%34%20%6%1
431
11th to 20thDay
19%13%27%28%11%2
625
21st to endDay
13%7%36%25%14%5%
679
June1st to 10thDay
10%6%23%29%26%5%
630
11th to 20thDay
8%427%36%21%4
630
21st to endDay
5%8%29%37%18%4
630
July1st to 10thDay
14%314%29%30%10%
621
11th to 20thDay
45%20%38%28%6%
618
21st to endDay
10%417%36%27%7%
684
August1st to 10thDay
10%118%39%24%7%
626
11th to 20thDay
11%318%34%26%8%
461
21st to endDay
11%116%32%33%8%
495
September1st to 10thDay
15%416%32%25%8%
450
11th to 20thDay
9%319%33%25%12%
450
21st to endDay
9%8%23%34%18%8%
387
October1st to 10thDay
13%13%29%31%11%2
270
11th to 20thDay
20%19%35%20%6%
270
21st to endDay
32%20%27%17%4
297
November1st to 10thDay
14%13%43%17%10%2
270
11th to 20thDay
23%18%34%16%8%1
270
21st to endDay
27%18%30%21%4
270
December1st to 10thDay
19%25%33%14%6%3
270
11th to 20thDay
24%21%36%15%31
270
21st to endDay
28%23%36%11%2
297
January1st to 10thNight
21%21%37%18%3
950
11th to 20thNight
22%23%33%17%4
905
21st to endNight
20%20%38%20%1
990
February1st to 10thNight
24%19%39%17%2
900
11th to 20thNight
21%18%41%17%2
753
21st to endNight
27%20%34%17%2
592
March1st to 10thNight
24%17%38%18%2
648
11th to 20thNight
25%14%38%21%3
540
21st to endNight
26%16%33%21%4
594
April1st to 10thNight
15%16%40%25%5%
540
11th to 20thNight
18%16%34%26%5%
533
21st to endNight
24%11%39%18%8%
540
May1st to 10thNight
18%9%33%31%8%
540
11th to 20thNight
19%7%28%32%14%1
531
21st to endNight
12%7%27%34%17%3
584
June1st to 10thNight
9%419%39%27%2
540
11th to 20thNight
8%225%43%20%2
540
21st to endNight
4226%43%23%2
540
July1st to 10thNight
10%112%38%31%7%
525
11th to 20thNight
4316%42%32%3
522
21st to endNight
7%216%44%28%4
591
August1st to 10thNight
6%213%43%33%3
537
11th to 20thNight
8%116%38%33%4
534
21st to endNight
6%216%35%36%5%
594
September1st to 10thNight
14%314%36%29%5%
540
11th to 20thNight
11%314%37%30%6%
540
21st to endNight
9%7%24%29%25%5%
688
October1st to 10thNight
9%429%33%22%3
720
11th to 20thNight
19%12%33%27%9%
720
21st to endNight
24%14%31%23%7%
792
November1st to 10thNight
14%10%38%29%8%1
740
11th to 20thNight
19%16%34%23%7%
760
21st to endNight
23%16%35%21%5%
855
December1st to 10thNight
23%15%37%20%41
950
11th to 20thNight
24%13%37%22%4
950
21st to endNight
26%19%35%19%2
1045
Page generated at 2024-01-08 10:14:17. Version ac07

Copyright 2024 Attilla Danko


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