Oliver Lee Memorial State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Oliver Lee Memorial State Park clear sky chart from 2005-11-06 to 2024-01-16.

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
54%
23875
31%
74558
20%
23822
66%
23822
42%
37783

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
49%
757
32%
2457
21%
756
63%
756
41%
1242
January11th to 20thNight
45%
744
33%
2418
22%
744
60%
744
41%
1186
January21st to endNight
44%
792
35%
2574
21%
792
62%
792
39%
1298
February1st to 10thNight
47%
720
35%
2203
21%
720
64%
720
47%
1074
February11th to 20thNight
36%
703
30%
2098
15%
700
51%
700
40%
1110
February21st to endNight
28%
592
35%
1776
12%
592
51%
592
40%
904
March1st to 10thNight
36%
720
33%
2047
13%
720
54%
720
39%
1107
March11th to 20thNight
46%
720
33%
1980
16%
720
59%
720
45%
1050
March21st to endNight
38%
720
37%
2106
15%
720
58%
720
44%
1049
April1st to 10thNight
33%
540
38%
1800
16%
540
61%
540
45%
816
April11th to 20thNight
35%
533
33%
1777
16%
533
57%
533
39%
826
April21st to endNight
36%
540
39%
1800
21%
540
63%
540
46%
808
May1st to 10thNight
42%
540
34%
1800
21%
540
63%
540
52%
773
May11th to 20thNight
54%
531
29%
1770
23%
531
67%
531
48%
812
May21st to endNight
51%
582
32%
1835
20%
582
68%
582
54%
823
June1st to 10thNight
62%
540
29%
1440
21%
540
68%
540
47%
800
June11th to 20thNight
64%
540
37%
1440
24%
540
73%
540
61%
707
June21st to endNight
68%
540
21%
1553
18%
540
70%
540
37%
903
July1st to 10thNight
73%
525
20%
1575
18%
525
74%
525
35%
918
July11th to 20thNight
78%
522
23%
1566
21%
522
79%
522
39%
878
July21st to endNight
76%
591
20%
1674
18%
558
77%
558
31%
1002
August1st to 10thNight
79%
537
17%
1779
21%
534
79%
534
32%
1037
August11th to 20thNight
77%
534
22%
1778
24%
534
80%
534
33%
1013
August21st to endNight
75%
594
23%
1980
26%
594
78%
594
34%
1116
September1st to 10thNight
73%
540
26%
1800
26%
540
77%
540
34%
1005
September11th to 20thNight
73%
540
33%
1800
34%
540
76%
540
38%
954
September21st to endNight
68%
544
34%
1974
31%
544
76%
544
45%
896
October1st to 10thNight
60%
720
31%
2160
22%
720
67%
720
46%
1114
October11th to 20thNight
61%
720
39%
2160
22%
720
73%
720
54%
1006
October21st to endNight
61%
792
40%
2376
24%
792
71%
792
55%
1088
November1st to 10thNight
60%
740
42%
2220
26%
740
72%
740
56%
1011
November11th to 20thNight
63%
866
39%
2386
22%
866
73%
866
60%
1125
November21st to endNight
49%
950
34%
2470
17%
950
59%
950
44%
1387
December1st to 10thNight
49%
950
36%
2470
19%
950
59%
950
45%
1377
December11th to 20thNight
39%
949
30%
3085
14%
948
53%
948
36%
1685
December21st to endNight
41%
907
21%
4431
18%
895
55%
895
30%
1883

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
5%3234345%6%8%59%
74673
Night
5%42342445%7%60%
75134
TransparencyDay
21%6%9%17%26%21%
74401
Night
21%6%8%16%27%22%
74929
SeeingDay
6%13%26%30%20%5%
13509
Night
6%8%27%36%20%3
23889

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
5%6%2342335%6%60%
1708
11th to 20thDay
7%31322345%7%64%
1669
21st to endDay
8%6%23323436%60%
1782
February1st to 10thDay
6%41332433467%
1754
11th to 20thDay
8%5%23423347%59%
1749
21st to endDay
6%423323335%67%
1480
March1st to 10thDay
8%5%3442345%6%57%
1910
11th to 20thDay
7%5%2432335%6%62%
1980
21st to endDay
432432435%7%63%
2248
April1st to 10thDay
421322345%7%67%
2160
11th to 20thDay
332331332473%
2131
21st to endDay
4212213346%72%
2160
May1st to 10thDay
3213323345%72%
2160
11th to 20thDay
2223325%46%7%64%
2125
21st to endDay
3112223337%74%
2428
June1st to 10thDay
221222446%9%65%
2520
11th to 20thDay
311222345%7%71%
2520
21st to endDay
4323435%7%7%10%52%
2397
July1st to 10thDay
6%3247%6%7%8%9%11%37%
2340
11th to 20thDay
32146%5%9%8%9%12%40%
2340
21st to endDay
5%325%6%5%10%10%11%13%30%
2545
August1st to 10thDay
4335%6%47%7%9%11%40%
2149
11th to 20thDay
44248%48%9%9%11%36%
2123
21st to endDay
4425%6%5%6%7%8%12%41%
2376
September1st to 10thDay
7%5%25%5%36%7%8%9%44%
2160
11th to 20thDay
7%324435%5%6%7%54%
2160
21st to endDay
421332345%8%65%
1982
October1st to 10thDay
5%31442435%7%61%
1800
11th to 20thDay
3323323345%71%
1800
21st to endDay
321222223476%
1980
November1st to 10thDay
2313323235%71%
1859
11th to 20thDay
4213323347%68%
1771
21st to endDay
7%4234235%5%8%59%
1710
December1st to 10thDay
8%5%13313348%60%
1710
11th to 20thDay
7%5%25%32346%7%55%
1960
21st to endDay
7%5%22223346%64%
3027
January1st to 10thNight
5%6%22424445%62%
2457
11th to 20thNight
7%423224345%64%
2418
21st to endNight
8%423423446%60%
2574
February1st to 10thNight
6%5%1232335%7%63%
2203
11th to 20thNight
10%423323345%60%
2098
21st to endNight
7%5%23323346%62%
1776
March1st to 10thNight
8%5%2432335%8%58%
2047
11th to 20thNight
8%41332345%6%61%
1980
21st to endNight
6%423313446%65%
2106
April1st to 10thNight
321332445%7%66%
1800
11th to 20thNight
7%322323446%64%
1777
21st to endNight
5%312213345%70%
1800
May1st to 10thNight
5%212213346%70%
1800
11th to 20thNight
3213324447%67%
1770
21st to endNight
321222445%6%70%
1835
June1st to 10thNight
22245%346%6%7%57%
1440
11th to 20thNight
32232335%7%68%
1440
21st to endNight
24246%46%6%8%10%48%
1553
July1st to 10thNight
3425%5%36%6%7%11%46%
1620
11th to 20thNight
3314446%6%8%12%48%
1620
21st to endNight
33245%46%8%11%13%42%
1773
August1st to 10thNight
33236%47%9%10%15%39%
1789
11th to 20thNight
5%324446%7%10%12%43%
1778
21st to endNight
33246%46%7%7%10%48%
1980
September1st to 10thNight
4325%6%35%6%7%9%50%
1800
11th to 20thNight
7%3244245%5%6%57%
1800
21st to endNight
4213424447%64%
1974
October1st to 10thNight
5%31342346%8%60%
2160
11th to 20thNight
4212323335%72%
2160
21st to endNight
5%21232223375%
2376
November1st to 10thNight
3312322437%71%
2220
11th to 20thNight
321232345%6%70%
2386
21st to endNight
8%423423347%61%
2470
December1st to 10thNight
9%41332345%7%59%
2470
11th to 20thNight
6%5%3432445%7%56%
3233
21st to endNight
8%5%13324335%63%
4651

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
23%5%9%17%31%15%
1709
11th to 20thDay
20%45%17%36%18%
1669
21st to endDay
25%46%15%31%19%
1782
February1st to 10thDay
21%36%17%27%26%
1754
11th to 20thDay
25%5%5%15%28%22%
1759
21st to endDay
20%349%32%33%
1480
March1st to 10thDay
26%47%12%30%21%
1910
11th to 20thDay
22%5%5%14%28%26%
1980
21st to endDay
17%5%7%13%33%24%
2248
April1st to 10thDay
15%36%16%32%28%
2160
11th to 20thDay
15%3412%29%37%
2134
21st to endDay
14%35%13%32%32%
2160
May1st to 10thDay
14%45%11%27%39%
2160
11th to 20thDay
17%7%9%14%26%27%
2128
21st to endDay
11%46%16%27%36%
2428
June1st to 10thDay
15%5%10%18%26%25%
2520
11th to 20thDay
12%46%13%24%42%
2520
21st to endDay
22%10%12%16%20%19%
2397
July1st to 10thDay
32%13%16%16%15%8%
2276
11th to 20thDay
27%14%18%21%15%4
2271
21st to endDay
31%17%24%18%9%1
2404
August1st to 10thDay
29%13%19%26%10%3
2136
11th to 20thDay
32%13%18%19%13%4
2123
21st to endDay
29%14%18%20%16%3
2376
September1st to 10thDay
31%9%14%17%19%11%
2160
11th to 20thDay
27%6%11%19%25%12%
2160
21st to endDay
17%6%9%21%32%15%
1982
October1st to 10thDay
21%6%9%17%26%20%
1800
11th to 20thDay
17%36%12%31%32%
1800
21st to endDay
14%26%19%34%26%
1980
November1st to 10thDay
16%36%20%31%24%
1859
11th to 20thDay
15%46%20%27%26%
1771
21st to endDay
22%5%8%16%31%18%
1710
December1st to 10thDay
22%47%21%31%15%
1710
11th to 20thDay
28%410%16%29%13%
1958
21st to endDay
20%46%17%31%22%
3027
January1st to 10thNight
23%5%6%16%31%19%
2457
11th to 20thNight
22%5%5%13%36%18%
2418
21st to endNight
24%47%14%31%20%
2574
February1st to 10thNight
20%37%15%25%28%
2203
11th to 20thNight
26%45%13%29%24%
2098
21st to endNight
21%5%5%9%28%32%
1776
March1st to 10thNight
24%46%12%28%25%
2047
11th to 20thNight
22%5%6%13%30%24%
1980
21st to endNight
20%45%12%34%25%
2106
April1st to 10thNight
17%45%11%35%27%
1800
11th to 20thNight
19%46%12%26%32%
1777
21st to endNight
16%5%5%13%32%29%
1800
May1st to 10thNight
16%35%11%28%38%
1800
11th to 20thNight
16%6%8%16%25%29%
1771
21st to endNight
14%47%15%25%35%
1836
June1st to 10thNight
22%7%9%17%19%27%
1440
11th to 20thNight
14%45%13%21%42%
1440
21st to endNight
25%11%13%15%16%19%
1553
July1st to 10thNight
28%10%15%21%18%8%
1575
11th to 20thNight
24%10%16%25%19%6%
1566
21st to endNight
25%15%22%23%12%2
1674
August1st to 10thNight
26%14%20%26%10%4
1779
11th to 20thNight
26%12%19%25%14%4
1778
21st to endNight
27%10%17%24%19%4
1980
September1st to 10thNight
27%9%13%16%21%13%
1800
11th to 20thNight
24%8%11%18%24%15%
1800
21st to endNight
18%6%10%17%32%16%
1974
October1st to 10thNight
21%6%11%15%26%21%
2160
11th to 20thNight
16%45%14%26%36%
2160
21st to endNight
16%3416%32%30%
2376
November1st to 10thNight
14%45%17%34%27%
2220
11th to 20thNight
14%48%16%32%27%
2386
21st to endNight
24%5%6%14%31%20%
2470
December1st to 10thNight
24%5%7%17%28%20%
2470
11th to 20thNight
26%5%9%18%25%17%
3234
21st to endNight
22%5%6%15%33%19%
4651

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
11%19%31%30%8%1
270
11th to 20thDay
12%17%32%28%10%2
257
21st to endDay
5%25%31%26%11%1
264
February1st to 10thDay
11%13%34%29%11%2
240
11th to 20thDay
15%20%38%21%5%1
240
21st to endDay
14%31%32%18%5%1
198
March1st to 10thDay
11%24%41%19%41
350
11th to 20thDay
12%24%30%26%6%2
420
21st to endDay
10%33%33%19%41
462
April1st to 10thDay
7%27%38%22%5%1
420
11th to 20thDay
8%30%39%18%5%
412
21st to endDay
8%30%35%23%5%1
420
May1st to 10thDay
420%42%26%6%1
423
11th to 20thDay
215%39%31%12%2
448
21st to endDay
213%44%31%9%
498
June1st to 10thDay
35%21%45%22%3
630
11th to 20thDay
25%25%40%26%2
630
21st to endDay
4220%37%31%6%
507
July1st to 10thDay
5%110%33%37%14%
446
11th to 20thDay
216%30%47%14%
444
21st to endDay
317%25%49%16%
487
August1st to 10thDay
26%28%47%16%
447
11th to 20thDay
4312%32%38%11%
437
21st to endDay
5%26%29%44%14%
495
September1st to 10thDay
7%213%37%34%8%
450
11th to 20thDay
7%113%43%29%7%
450
21st to endDay
4421%44%20%7%
280
October1st to 10thDay
8%424%34%25%4
270
11th to 20thDay
49%22%38%21%6%
270
21st to endDay
6%13%27%28%20%7%
297
November1st to 10thDay
5%17%33%26%16%4
270
11th to 20thDay
410%27%34%20%4
270
21st to endDay
9%19%34%24%13%1
270
December1st to 10thDay
12%15%31%29%11%2
270
11th to 20thDay
7%24%33%27%8%
270
21st to endDay
14%20%36%25%6%
297
January1st to 10thNight
7%8%33%36%13%3
760
11th to 20thNight
9%9%34%32%13%3
744
21st to endNight
10%11%31%31%15%2
792
February1st to 10thNight
8%10%33%33%13%2
720
11th to 20thNight
11%12%39%30%8%
704
21st to endNight
8%17%45%25%5%1
592
March1st to 10thNight
10%16%35%29%8%1
720
11th to 20thNight
8%13%32%34%13%1
720
21st to endNight
6%16%38%30%9%1
720
April1st to 10thNight
313%47%29%7%
540
11th to 20thNight
9%17%37%30%7%
533
21st to endNight
7%14%42%30%7%
540
May1st to 10thNight
5%9%42%35%9%
540
11th to 20thNight
38%32%40%16%1
531
21st to endNight
37%36%43%10%1
584
June1st to 10thNight
2427%47%19%1
540
11th to 20thNight
3425%46%20%1
540
21st to endNight
3317%49%26%2
540
July1st to 10thNight
4212%47%33%2
525
11th to 20thNight
418%40%42%5%
522
21st to endNight
329%37%42%7%
591
August1st to 10thNight
416%31%48%11%
537
11th to 20thNight
428%31%45%10%
534
21st to endNight
3211%36%43%6%
594
September1st to 10thNight
5%113%39%36%6%
540
11th to 20thNight
7%19%46%34%2
540
21st to endNight
4419%43%27%3
544
October1st to 10thNight
6%325%41%22%3
720
11th to 20thNight
5%5%26%39%22%4
720
21st to endNight
6%6%23%32%26%6%
792
November1st to 10thNight
48%25%34%25%5%
740
11th to 20thNight
46%24%41%22%3
866
21st to endNight
9%10%27%32%19%3
950
December1st to 10thNight
10%10%27%36%16%1
950
11th to 20thNight
10%10%37%29%14%1
950
21st to endNight
12%11%32%33%11%2
914
Page generated at 2024-01-13 17:28:32. Version ac07

Copyright 2024 Attilla Danko


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