Keowee-Toxaway State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Keowee-Toxaway State Park 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
48%
24009
22%
74341
15%
23954
55%
23954
26%
46762

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
33%
760
24%
2459
12%
757
49%
757
25%
1495
January11th to 20thNight
33%
732
24%
2378
13%
732
47%
732
23%
1482
January21st to endNight
30%
792
27%
2574
14%
792
47%
792
25%
1536
February1st to 10thNight
36%
720
25%
2217
13%
720
48%
720
27%
1352
February11th to 20thNight
28%
703
23%
2098
10%
699
41%
699
24%
1363
February21st to endNight
30%
592
23%
1776
13%
592
41%
592
22%
1161
March1st to 10thNight
36%
720
26%
2039
15%
720
46%
720
31%
1251
March11th to 20thNight
34%
720
20%
1980
10%
720
42%
720
27%
1295
March21st to endNight
35%
792
20%
2178
10%
792
43%
792
26%
1436
April1st to 10thNight
40%
720
25%
1980
13%
720
49%
720
32%
1199
April11th to 20thNight
43%
605
26%
1784
16%
605
52%
605
32%
1064
April21st to endNight
53%
540
29%
1620
20%
540
59%
540
34%
951
May1st to 10thNight
53%
540
19%
1620
10%
540
60%
540
30%
989
May11th to 20thNight
49%
531
13%
1593
8%
531
52%
531
23%
1078
May21st to endNight
60%
582
18%
1744
14%
582
62%
582
27%
1134
June1st to 10thNight
63%
540
14%
1620
12%
540
65%
540
24%
1082
June11th to 20thNight
64%
540
14%
1620
11%
540
66%
540
30%
1037
June21st to endNight
69%
540
14%
1620
10%
540
70%
540
26%
1064
July1st to 10thNight
64%
525
9%
1575
8%
525
64%
525
21%
1120
July11th to 20thNight
69%
522
11%
1566
9%
522
70%
522
23%
1076
July21st to endNight
66%
591
14%
1672
11%
558
67%
558
24%
1137
August1st to 10thNight
62%
537
12%
1600
11%
534
63%
534
21%
1122
August11th to 20thNight
60%
534
16%
1598
13%
534
62%
534
21%
1133
August21st to endNight
63%
632
16%
1985
16%
632
63%
632
22%
1365
September1st to 10thNight
63%
720
18%
1980
15%
720
64%
720
28%
1335
September11th to 20thNight
56%
720
18%
1980
14%
720
58%
720
24%
1378
September21st to endNight
56%
720
24%
1980
19%
720
61%
720
31%
1275
October1st to 10thNight
54%
720
27%
1986
23%
720
59%
720
34%
1225
October11th to 20thNight
52%
720
28%
2160
24%
720
60%
720
33%
1266
October21st to endNight
55%
792
33%
2376
26%
792
65%
792
37%
1340
November1st to 10thNight
56%
740
29%
2309
25%
740
63%
740
35%
1301
November11th to 20thNight
43%
760
28%
2470
21%
760
57%
760
31%
1413
November21st to endNight
47%
760
27%
2470
20%
760
58%
760
28%
1457
December1st to 10thNight
39%
760
24%
2470
16%
760
51%
760
22%
1602
December11th to 20thNight
40%
758
29%
2892
17%
758
52%
758
25%
1613
December21st to endNight
34%
829
15%
4372
15%
817
44%
817
12%
2635

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
14%5%245%35%5%6%8%43%
74891
Night
16%5%2443445%7%44%
74859
TransparencyDay
39%6%12%21%18%5%
74614
Night
39%5%10%20%19%6%
74655
SeeingDay
19%7%21%25%18%9%
13901
Night
18%6%20%31%20%4
24020

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
19%424323346%51%
1706
11th to 20thDay
20%6%24425%43446%
1638
21st to endDay
17%424323346%51%
1782
February1st to 10thDay
17%5%25%423447%45%
1742
11th to 20thDay
21%6%23433347%44%
1748
21st to endDay
22%6%25%5%2343443%
1480
March1st to 10thDay
17%42332445%6%50%
1921
11th to 20thDay
20%5%35%5%2445%7%41%
1980
21st to endDay
18%6%24425%5%5%7%41%
2178
April1st to 10thDay
12%425%425%46%9%47%
1980
11th to 20thDay
14%3245%35%5%6%7%46%
2135
21st to endDay
12%324425%45%7%50%
2340
May1st to 10thDay
11%425%5%346%5%7%47%
2340
11th to 20thDay
14%6%345%46%5%8%8%38%
2301
21st to endDay
12%5%25%5%46%6%7%10%39%
2531
June1st to 10thDay
12%5%25%6%37%7%8%11%34%
2340
11th to 20thDay
7%425%6%5%8%7%8%11%38%
2340
21st to endDay
7%425%6%47%8%8%12%37%
2340
July1st to 10thDay
8%6%36%7%5%8%9%8%10%30%
2340
11th to 20thDay
9%5%35%7%5%8%8%9%12%29%
2340
21st to endDay
7%427%8%5%8%8%7%12%32%
2547
August1st to 10thDay
12%6%25%7%5%7%8%8%11%29%
2327
11th to 20thDay
11%5%26%7%5%7%7%7%11%33%
2303
21st to endDay
12%6%27%5%36%7%8%10%35%
2347
September1st to 10thDay
9%5%25%6%37%7%7%9%41%
1980
11th to 20thDay
15%6%25%5%45%5%6%8%39%
1980
21st to endDay
15%5%25%435%5%46%45%
1980
October1st to 10thDay
14%5%23423246%55%
1972
11th to 20thDay
13%5%24322346%57%
1800
21st to endDay
14%41332334458%
1980
November1st to 10thDay
13%5%13313335%59%
1766
11th to 20thDay
15%42432335%6%55%
1710
21st to endDay
16%5%2332345%6%51%
1710
December1st to 10thDay
22%6%35%423346%41%
1710
11th to 20thDay
19%413423346%51%
2153
21st to endDay
24%41332345%7%45%
3124
January1st to 10thNight
20%423434345%49%
2459
11th to 20thNight
18%6%235%34346%45%
2378
21st to endNight
16%6%34324345%49%
2574
February1st to 10thNight
17%42442445%5%49%
2217
11th to 20thNight
21%6%24433445%45%
2098
21st to endNight
20%6%245%3445%6%41%
1776
March1st to 10thNight
15%6%34423446%49%
2039
11th to 20thNight
18%5%34435%45%7%44%
1980
21st to endNight
18%6%35%4345%5%6%43%
2178
April1st to 10thNight
14%5%24333347%52%
1980
11th to 20thNight
14%5%25%42435%6%51%
1784
21st to endNight
12%425%32445%8%51%
1620
May1st to 10thNight
12%5%34425%6%5%6%47%
1620
11th to 20thNight
15%6%36%5%35%5%7%8%38%
1592
21st to endNight
13%6%247%25%5%6%9%40%
1744
June1st to 10thNight
10%6%25%6%46%7%8%11%35%
1620
11th to 20thNight
9%425%6%36%5%6%10%43%
1620
21st to endNight
8%5%25%6%36%7%8%11%38%
1620
July1st to 10thNight
10%6%37%7%46%6%10%11%29%
1620
11th to 20thNight
10%5%25%6%47%9%8%14%30%
1620
21st to endNight
7%5%27%7%47%7%9%10%34%
1771
August1st to 10thNight
13%6%36%6%5%6%7%8%10%30%
1611
11th to 20thNight
12%6%46%7%47%7%6%9%32%
1598
21st to endNight
12%6%47%6%46%5%6%11%34%
1985
September1st to 10thNight
12%6%26%6%45%6%7%8%39%
1980
11th to 20thNight
16%6%36%6%346%5%7%37%
1980
21st to endNight
15%6%345%3445%6%45%
1980
October1st to 10thNight
16%5%24433436%52%
1986
11th to 20thNight
15%5%23424445%52%
2160
21st to endNight
14%31332335%457%
2376
November1st to 10thNight
15%423323335%57%
2309
11th to 20thNight
17%424323245%53%
2470
21st to endNight
18%3224245%5%6%49%
2470
December1st to 10thNight
21%5%25%434445%43%
2470
11th to 20thNight
17%5%24323335%54%
3042
21st to endNight
24%5%2442445%6%39%
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
38%47%22%22%7%
1707
11th to 20thDay
44%37%19%21%7%
1638
21st to endDay
36%26%23%24%8%
1782
February1st to 10thDay
41%38%21%19%7%
1742
11th to 20thDay
43%47%19%21%6%
1758
21st to endDay
47%37%15%19%10%
1480
March1st to 10thDay
37%37%19%23%10%
1921
11th to 20thDay
43%5%10%18%16%8%
1980
21st to endDay
42%6%10%21%18%3
2178
April1st to 10thDay
35%410%21%23%7%
1980
11th to 20thDay
38%48%21%20%9%
2135
21st to endDay
32%411%27%21%4
2340
May1st to 10thDay
35%7%13%21%19%5%
2340
11th to 20thDay
42%7%17%20%12%2
2305
21st to endDay
38%8%15%24%14%2
2531
June1st to 10thDay
40%8%18%24%8%2
2340
11th to 20thDay
35%9%21%22%11%2
2340
21st to endDay
37%10%18%21%12%3
2340
July1st to 10thDay
44%9%19%17%9%2
2275
11th to 20thDay
40%11%23%16%6%3
2271
21st to endDay
40%10%21%20%8%1
2405
August1st to 10thDay
45%10%18%20%7%
2314
11th to 20thDay
42%10%18%21%7%1
2303
21st to endDay
42%9%18%20%9%2
2347
September1st to 10thDay
37%8%15%19%17%3
1980
11th to 20thDay
43%6%12%19%19%2
1980
21st to endDay
38%5%10%23%18%6%
1980
October1st to 10thDay
32%410%21%28%6%
1972
11th to 20thDay
31%39%25%23%10%
1800
21st to endDay
31%26%21%28%11%
1980
November1st to 10thDay
30%37%19%30%11%
1766
11th to 20thDay
33%36%20%28%9%
1710
21st to endDay
35%47%21%25%8%
1710
December1st to 10thDay
47%36%19%18%6%
1710
11th to 20thDay
37%37%20%21%12%
2150
21st to endDay
40%5%6%22%23%4
3124
January1st to 10thNight
40%38%18%24%7%
2459
11th to 20thNight
42%48%17%23%6%
2378
21st to endNight
39%35%20%25%8%
2574
February1st to 10thNight
38%48%22%21%7%
2217
11th to 20thNight
44%35%19%23%6%
2099
21st to endNight
45%38%16%19%8%
1776
March1st to 10thNight
38%38%17%23%12%
2039
11th to 20thNight
41%5%11%15%21%7%
1980
21st to endNight
43%49%20%21%4
2178
April1st to 10thNight
35%39%21%26%6%
1980
11th to 20thNight
35%36%23%23%9%
1784
21st to endNight
34%410%26%22%4
1620
May1st to 10thNight
36%6%13%23%20%3
1620
11th to 20thNight
45%7%15%18%15%1
1593
21st to endNight
40%7%13%25%13%2
1745
June1st to 10thNight
41%10%16%22%10%2
1620
11th to 20thNight
35%9%19%23%12%1
1620
21st to endNight
36%12%18%17%12%5%
1620
July1st to 10thNight
45%11%20%14%9%1
1575
11th to 20thNight
40%13%23%15%7%2
1566
21st to endNight
39%12%22%20%6%1
1672
August1st to 10thNight
46%9%19%18%8%
1600
11th to 20thNight
44%12%17%16%10%1
1598
21st to endNight
45%8%16%20%7%3
1985
September1st to 10thNight
40%8%14%21%13%3
1980
11th to 20thNight
44%8%12%18%16%2
1980
21st to endNight
38%5%10%22%18%6%
1980
October1st to 10thNight
34%6%10%17%28%6%
1986
11th to 20thNight
35%48%22%21%10%
2160
21st to endNight
31%3421%28%12%
2376
November1st to 10thNight
33%37%19%27%12%
2309
11th to 20thNight
36%2418%29%11%
2470
21st to endNight
37%45%22%26%7%
2470
December1st to 10thNight
46%47%18%19%7%
2470
11th to 20thNight
36%37%18%26%11%
3044
21st to endNight
45%5%6%21%19%4
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
25%14%37%21%3
270
11th to 20thDay
28%15%30%21%5%1
246
21st to endDay
26%16%42%12%4
264
February1st to 10thDay
26%14%39%17%4
240
11th to 20thDay
39%13%33%14%2
240
21st to endDay
37%18%31%11%3
198
March1st to 10thDay
21%12%33%25%9%1
361
11th to 20thDay
25%10%33%24%6%1
420
21st to endDay
27%15%28%21%9%1
462
April1st to 10thDay
21%13%27%26%10%2
420
11th to 20thDay
17%13%31%25%12%2
412
21st to endDay
19%9%24%26%15%6%
420
May1st to 10thDay
17%8%32%26%10%7%
423
11th to 20thDay
21%6%15%27%22%9%
447
21st to endDay
18%418%25%22%14%
485
June1st to 10thDay
15%5%13%32%23%13%
450
11th to 20thDay
10%6%14%24%27%20%
450
21st to endDay
11%316%30%22%18%
450
July1st to 10thDay
13%29%22%30%24%
445
11th to 20thDay
8%27%28%30%25%
444
21st to endDay
6%28%28%33%23%
488
August1st to 10thDay
18%213%24%25%19%
446
11th to 20thDay
12%27%28%35%17%
439
21st to endDay
14%39%27%26%20%
495
September1st to 10thDay
13%210%27%33%15%
450
11th to 20thDay
18%410%22%31%15%
450
21st to endDay
19%414%30%23%10%
450
October1st to 10thDay
21%415%30%20%11%
450
11th to 20thDay
17%6%19%34%20%4
450
21st to endDay
19%5%22%31%19%4
495
November1st to 10thDay
24%423%29%17%4
364
11th to 20thDay
20%13%31%27%7%1
270
21st to endDay
15%10%35%28%10%2
270
December1st to 10thDay
32%9%30%22%7%
270
11th to 20thDay
25%10%34%21%9%1
270
21st to endDay
32%12%29%19%6%2
297
January1st to 10thNight
23%10%29%32%6%
760
11th to 20thNight
23%11%27%33%6%
732
21st to endNight
21%11%32%32%3
792
February1st to 10thNight
19%10%30%37%4
720
11th to 20thNight
25%10%33%29%3
703
21st to endNight
23%12%30%30%5%
592
March1st to 10thNight
19%8%31%37%5%
720
11th to 20thNight
19%9%31%32%9%1
720
21st to endNight
21%9%27%32%10%1
792
April1st to 10thNight
17%12%27%33%12%
720
11th to 20thNight
17%9%25%33%15%1
605
21st to endNight
14%5%21%38%21%2
540
May1st to 10thNight
15%5%19%37%22%1
540
11th to 20thNight
17%418%31%26%5%
531
21st to endNight
16%211%27%37%8%
584
June1st to 10thNight
15%27%31%39%7%
540
11th to 20thNight
11%212%25%35%15%
540
21st to endNight
9%29%32%39%9%
540
July1st to 10thNight
13%3422%43%14%
525
11th to 20thNight
11%2422%43%18%
522
21st to endNight
9%35%25%43%14%
591
August1st to 10thNight
18%3422%41%13%
537
11th to 20thNight
17%17%25%39%10%
534
21st to endNight
16%26%24%40%12%
632
September1st to 10thNight
12%38%29%36%11%
720
11th to 20thNight
20%210%24%35%7%
720
21st to endNight
18%314%33%29%4
720
October1st to 10thNight
18%317%28%26%7%
720
11th to 20thNight
17%419%35%21%3
720
21st to endNight
17%5%19%37%19%4
792
November1st to 10thNight
17%319%36%20%4
740
11th to 20thNight
20%6%26%33%13%1
760
21st to endNight
19%6%23%38%14%1
760
December1st to 10thNight
25%6%23%35%10%1
760
11th to 20thNight
20%6%27%36%11%1
760
21st to endNight
29%8%22%34%7%
836
Page generated at 2024-01-10 10:16:08. Version ac07

Copyright 2024 Attilla Danko


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