Lake Somerville State Park - Nails Creek Unit
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake Somerville State Park - Nails Creek Unit clear sky chart from 2005-11-06 to 2024-01-13.

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
50%
23747
24%
74266
17%
23692
57%
23692
31%
43446

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
35%
946
27%
2458
11%
946
45%
946
32%
1564
January11th to 20thNight
35%
915
25%
2379
10%
915
43%
915
31%
1507
January21st to endNight
34%
990
28%
2574
11%
990
44%
990
31%
1659
February1st to 10thNight
28%
737
24%
2177
9%
737
39%
737
23%
1418
February11th to 20thNight
28%
704
21%
2098
9%
700
37%
700
26%
1330
February21st to endNight
19%
520
24%
1704
6%
520
35%
520
21%
1088
March1st to 10thNight
26%
540
23%
1980
9%
540
41%
540
20%
1221
March11th to 20thNight
33%
540
21%
1980
14%
540
42%
540
21%
1221
March21st to endNight
31%
594
25%
2178
15%
594
46%
594
26%
1238
April1st to 10thNight
30%
540
24%
1980
13%
540
46%
540
26%
1133
April11th to 20thNight
32%
533
21%
1891
14%
533
44%
533
24%
1126
April21st to endNight
32%
540
25%
1778
15%
540
48%
540
29%
1054
May1st to 10thNight
32%
540
22%
1620
15%
540
44%
540
27%
1022
May11th to 20thNight
46%
531
23%
1594
21%
531
53%
531
33%
954
May21st to endNight
53%
584
24%
1746
20%
582
62%
582
34%
1029
June1st to 10thNight
71%
540
22%
1620
24%
540
75%
540
44%
852
June11th to 20thNight
68%
540
23%
1620
23%
540
75%
540
48%
829
June21st to endNight
75%
540
20%
1620
24%
540
77%
540
36%
951
July1st to 10thNight
76%
525
18%
1575
20%
525
78%
525
35%
921
July11th to 20thNight
83%
522
25%
1566
28%
522
85%
522
47%
796
July21st to endNight
85%
591
21%
1673
23%
558
87%
558
48%
856
August1st to 10thNight
90%
537
28%
1601
32%
534
91%
534
60%
732
August11th to 20thNight
81%
534
26%
1600
28%
534
82%
534
40%
878
August21st to endNight
81%
594
18%
2154
23%
594
82%
594
32%
1185
September1st to 10thNight
80%
540
20%
1980
23%
540
82%
540
34%
1060
September11th to 20thNight
69%
540
22%
1980
25%
540
70%
540
26%
1171
September21st to endNight
70%
540
27%
1980
29%
540
72%
540
34%
1038
October1st to 10thNight
75%
556
35%
1996
36%
556
78%
556
44%
939
October11th to 20thNight
59%
720
32%
2160
22%
720
65%
720
41%
1193
October21st to endNight
50%
792
32%
2376
20%
792
57%
792
38%
1314
November1st to 10thNight
56%
740
29%
2220
20%
740
61%
740
35%
1289
November11th to 20thNight
49%
760
26%
2280
17%
760
57%
760
32%
1355
November21st to endNight
39%
945
26%
2465
13%
945
46%
945
30%
1601
December1st to 10thNight
41%
950
28%
2470
15%
950
48%
950
30%
1620
December11th to 20thNight
34%
949
24%
2885
11%
948
40%
948
23%
1886
December21st to endNight
36%
1038
17%
4308
11%
1026
44%
1026
21%
2416

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%6%25%5%35%5%6%8%45%
74923
Night
11%5%2442445%7%51%
74847
TransparencyDay
38%7%11%19%18%8%
74648
Night
33%6%12%20%19%10%
74642
SeeingDay
12%6%19%27%26%10%
13746
Night
13%7%25%36%18%2
23759

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
18%6%24433445%48%
1707
11th to 20thDay
18%7%2442425%6%45%
1643
21st to endDay
16%6%35%5%23345%48%
1782
February1st to 10thDay
21%9%45%423335%41%
1799
11th to 20thDay
20%9%35%433345%42%
1749
21st to endDay
18%8%26%434445%42%
1549
March1st to 10thDay
20%8%36%5%35%446%37%
1980
11th to 20thDay
16%8%46%5%34346%42%
1980
21st to endDay
16%6%36%423445%46%
2178
April1st to 10thDay
14%7%37%5%345%48%39%
1980
11th to 20thDay
14%7%37%6%35%45%5%42%
2016
21st to endDay
13%5%36%5%35%45%7%46%
2177
May1st to 10thDay
12%6%35%6%35%5%6%9%40%
2340
11th to 20thDay
11%6%36%6%35%5%6%7%43%
2302
21st to endDay
11%6%36%7%46%5%8%9%35%
2531
June1st to 10thDay
5%4245%46%6%8%10%46%
2340
11th to 20thDay
5%3245%36%7%7%10%47%
2340
21st to endDay
6%5%36%7%5%8%7%9%10%36%
2340
July1st to 10thDay
9%5%36%8%46%6%8%11%34%
2340
11th to 20thDay
4325%5%47%7%8%12%44%
2340
21st to endDay
3325%6%46%6%7%13%45%
2546
August1st to 10thDay
3214435%6%5%10%57%
2328
11th to 20thDay
5%325%445%6%7%10%48%
2301
21st to endDay
5%425%6%5%5%6%8%11%43%
2197
September1st to 10thDay
5%5%26%6%46%6%6%10%44%
1980
11th to 20thDay
12%6%25%6%46%5%5%8%41%
1980
21st to endDay
6%4246%46%6%6%7%49%
1980
October1st to 10thDay
6%3234345%6%8%56%
1944
11th to 20thDay
13%5%2442445%5%54%
1800
21st to endDay
13%5%14323346%56%
1980
November1st to 10thDay
12%6%25%4345%5%7%48%
1858
11th to 20thDay
11%7%25%424347%52%
1900
21st to endDay
18%7%25%5%34445%42%
1710
December1st to 10thDay
15%8%25%6%23446%45%
1710
11th to 20thDay
18%7%25%5%34346%43%
2161
21st to endDay
16%8%35%423345%48%
3135
January1st to 10thNight
17%6%24323346%50%
2458
11th to 20thNight
17%7%24323335%50%
2379
21st to endNight
16%6%34423345%50%
2574
February1st to 10thNight
17%8%36%423335%45%
2177
11th to 20thNight
20%7%35%423335%48%
2098
21st to endNight
20%5%45%334446%43%
1704
March1st to 10thNight
16%8%25%42445%8%42%
1980
11th to 20thNight
14%7%35%5%3445%6%43%
1980
21st to endNight
14%5%24424446%51%
2178
April1st to 10thNight
11%6%345%3446%8%47%
1980
11th to 20thNight
13%6%35%43445%8%45%
1891
21st to endNight
13%6%245%3345%6%49%
1778
May1st to 10thNight
11%436%5%35%47%9%44%
1620
11th to 20thNight
9%5%2443446%8%49%
1593
21st to endNight
6%5%245%36%5%6%9%49%
1745
June1st to 10thNight
42244235%6%10%59%
1620
11th to 20thNight
42133146%6%10%60%
1620
21st to endNight
4325%5%35%6%8%11%49%
1620
July1st to 10thNight
6%323435%6%7%12%48%
1620
11th to 20thNight
2213325%5%6%10%61%
1620
21st to endNight
3213335%5%7%13%56%
1772
August1st to 10thNight
111222345%12%68%
1611
11th to 20thNight
3314435%5%7%13%51%
1600
21st to endNight
4324436%6%8%12%49%
2154
September1st to 10thNight
6%324435%6%6%9%53%
1980
11th to 20thNight
10%5%25%5%3445%9%46%
1980
21st to endNight
7%3244336%6%9%55%
1980
October1st to 10thNight
43134235%5%7%63%
1996
11th to 20thNight
11%423323346%58%
2160
21st to endNight
12%5%2332334460%
2376
November1st to 10thNight
11%5%23433446%54%
2220
11th to 20thNight
10%6%24434446%52%
2280
21st to endNight
16%6%35%434447%46%
2465
December1st to 10thNight
16%7%34424346%47%
2470
11th to 20thNight
16%8%345%24446%44%
3036
21st to endNight
16%7%24423345%52%
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
40%45%18%21%12%
1708
11th to 20thDay
41%46%17%21%11%
1643
21st to endDay
40%36%14%23%14%
1782
February1st to 10thDay
47%46%12%19%13%
1799
11th to 20thDay
47%38%15%18%9%
1759
21st to endDay
44%5%8%15%16%13%
1549
March1st to 10thDay
48%7%7%11%20%7%
1980
11th to 20thDay
45%5%6%12%20%12%
1980
21st to endDay
41%5%7%16%22%8%
2178
April1st to 10thDay
45%6%7%18%15%10%
1980
11th to 20thDay
44%6%8%14%19%10%
2016
21st to endDay
39%5%7%19%23%7%
2177
May1st to 10thDay
41%8%9%17%17%9%
2340
11th to 20thDay
39%7%12%21%18%3
2306
21st to endDay
43%9%12%21%13%2
2531
June1st to 10thDay
31%9%15%26%16%3
2340
11th to 20thDay
30%10%15%25%17%4
2340
21st to endDay
39%12%13%22%12%2
2340
July1st to 10thDay
41%10%17%22%9%1
2276
11th to 20thDay
29%10%21%22%17%1
2271
21st to endDay
25%12%22%31%9%1
2405
August1st to 10thDay
22%10%18%34%15%1
2314
11th to 20thDay
30%11%20%26%11%3
2301
21st to endDay
33%11%17%24%12%3
2197
September1st to 10thDay
36%10%13%19%16%6%
1980
11th to 20thDay
41%9%13%16%17%4
1980
21st to endDay
33%7%10%21%17%12%
1980
October1st to 10thDay
26%6%11%21%23%13%
1944
11th to 20thDay
34%49%15%22%16%
1800
21st to endDay
32%46%15%24%19%
1980
November1st to 10thDay
35%7%9%18%21%11%
1858
11th to 20thDay
33%5%10%17%21%13%
1900
21st to endDay
43%49%15%18%11%
1710
December1st to 10thDay
42%5%9%17%20%8%
1710
11th to 20thDay
43%5%7%11%23%10%
2159
21st to endDay
40%36%13%26%11%
3135
January1st to 10thNight
38%46%17%21%14%
2458
11th to 20thNight
38%37%16%22%14%
2379
21st to endNight
39%3415%21%17%
2574
February1st to 10thNight
44%36%12%19%16%
2177
11th to 20thNight
42%37%15%19%14%
2098
21st to endNight
44%47%13%15%15%
1704
March1st to 10thNight
42%6%10%14%18%10%
1980
11th to 20thNight
42%6%10%13%19%11%
1980
21st to endNight
35%6%10%16%20%12%
2178
April1st to 10thNight
35%6%11%20%17%11%
1980
11th to 20thNight
39%5%11%15%16%14%
1891
21st to endNight
36%5%9%22%20%8%
1778
May1st to 10thNight
37%7%11%19%17%8%
1620
11th to 20thNight
32%8%13%25%18%4
1594
21st to endNight
31%7%16%30%14%1
1746
June1st to 10thNight
22%7%17%31%22%2
1620
11th to 20thNight
19%8%18%33%18%5%
1620
21st to endNight
28%9%18%29%15%2
1620
July1st to 10thNight
27%10%23%30%9%
1575
11th to 20thNight
17%9%26%32%15%1
1566
21st to endNight
17%10%31%32%10%
1673
August1st to 10thNight
11%7%26%36%19%2
1601
11th to 20thNight
24%9%22%33%10%2
1600
21st to endNight
25%12%23%27%10%3
2154
September1st to 10thNight
26%9%19%23%15%7%
1980
11th to 20thNight
36%8%15%22%14%6%
1980
21st to endNight
26%8%15%19%18%13%
1980
October1st to 10thNight
20%6%12%26%21%14%
1996
11th to 20thNight
29%48%19%23%18%
2160
21st to endNight
29%47%17%21%22%
2376
November1st to 10thNight
31%6%9%20%21%12%
2220
11th to 20thNight
34%5%9%19%20%13%
2280
21st to endNight
39%5%8%16%18%13%
2465
December1st to 10thNight
39%6%7%21%17%10%
2470
11th to 20thNight
42%5%7%10%21%15%
3037
21st to endNight
37%45%14%29%11%
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
23%7%37%24%7%2
270
11th to 20thDay
19%13%29%28%8%2
248
21st to endDay
19%16%36%22%6%
264
February1st to 10thDay
31%11%30%21%6%
240
11th to 20thDay
28%17%29%19%7%
240
21st to endDay
26%19%35%16%41
198
March1st to 10thDay
20%18%33%21%8%
240
11th to 20thDay
18%16%39%20%6%1
240
21st to endDay
17%14%36%24%7%1
264
April1st to 10thDay
16%14%42%21%6%1
240
11th to 20thDay
19%18%28%24%10%1
294
21st to endDay
14%12%36%26%11%1
437
May1st to 10thDay
12%10%35%32%11%1
603
11th to 20thDay
13%6%25%34%17%4
625
21st to endDay
11%6%24%36%20%3
679
June1st to 10thDay
5%212%40%33%9%
630
11th to 20thDay
6%113%41%32%7%
630
21st to endDay
6%312%30%37%13%
630
July1st to 10thDay
6%28%29%38%17%
621
11th to 20thDay
2330%46%19%
618
21st to endDay
31424%49%18%
684
August1st to 10thDay
3324%50%20%
626
11th to 20thDay
5%322%50%20%
615
21st to endDay
6%1319%30%40%
316
September1st to 10thDay
6%1320%38%32%
270
11th to 20thDay
7%25%19%39%29%
270
21st to endDay
8%17%21%41%22%
270
October1st to 10thDay
3211%30%40%14%
270
11th to 20thDay
12%418%31%25%10%
270
21st to endDay
20%11%23%22%19%6%
297
November1st to 10thDay
16%6%17%34%20%7%
270
11th to 20thDay
19%9%23%29%16%5%
270
21st to endDay
22%16%32%19%9%3
270
December1st to 10thDay
19%7%31%24%14%6%
270
11th to 20thDay
23%15%27%25%7%2
270
21st to endDay
23%7%38%23%6%2
297
January1st to 10thNight
20%9%32%31%8%
950
11th to 20thNight
21%11%29%31%8%
915
21st to endNight
18%12%32%31%6%
990
February1st to 10thNight
23%12%33%28%4
737
11th to 20thNight
23%11%35%26%5%
704
21st to endNight
25%13%41%18%3
520
March1st to 10thNight
18%13%40%26%3
540
11th to 20thNight
15%12%37%31%5%
540
21st to endNight
14%10%41%29%5%
594
April1st to 10thNight
12%10%44%31%4
540
11th to 20thNight
13%14%37%29%6%
533
21st to endNight
12%11%40%27%8%1
540
May1st to 10thNight
12%10%43%30%5%
540
11th to 20thNight
9%7%34%37%13%1
531
21st to endNight
5%431%43%16%1
584
June1st to 10thNight
4215%51%26%2
540
11th to 20thNight
3124%50%21%1
540
21st to endNight
4111%47%33%4
540
July1st to 10thNight
5%19%46%34%3
525
11th to 20thNight
217%51%36%3
522
21st to endNight
35%52%36%3
591
August1st to 10thNight
1456%36%3
537
11th to 20thNight
45%51%35%5%
534
21st to endNight
415%36%48%6%
594
September1st to 10thNight
6%17%33%47%6%
540
11th to 20thNight
10%17%34%44%4
540
21st to endNight
9%113%33%40%4
540
October1st to 10thNight
4112%44%34%5%
556
11th to 20thNight
12%421%40%21%2
720
21st to endNight
13%8%27%32%19%2
792
November1st to 10thNight
12%422%41%20%1
740
11th to 20thNight
11%9%24%38%15%1
760
21st to endNight
17%11%29%29%14%1
945
December1st to 10thNight
18%8%27%33%12%1
950
11th to 20thNight
23%11%28%30%7%1
950
21st to endNight
19%9%31%31%9%
1045
Page generated at 2024-01-10 18:35:21. Version ac07

Copyright 2024 Attilla Danko


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