Santee State Park
Clear Sky Chart
History

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

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
49%
25373
20%
96845
15%
25117
57%
25117
23%
58678

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
31%
755
24%
3990
10%
737
47%
737
16%
2220
January11th to 20thNight
35%
754
26%
3974
14%
740
50%
740
17%
2185
January21st to endNight
28%
827
18%
4440
13%
814
44%
814
16%
2551
February1st to 10thNight
36%
760
23%
2470
13%
760
49%
760
25%
1503
February11th to 20thNight
28%
742
22%
2233
10%
740
40%
740
24%
1423
February21st to endNight
29%
628
24%
1780
11%
628
41%
628
28%
1122
March1st to 10thNight
36%
757
19%
3410
17%
745
47%
745
17%
2362
March11th to 20thNight
36%
757
28%
3406
12%
740
45%
740
22%
1699
March21st to endNight
38%
832
17%
3705
10%
814
49%
814
21%
2073
April1st to 10thNight
40%
760
24%
2088
13%
760
48%
760
31%
1271
April11th to 20thNight
46%
751
26%
1875
13%
751
52%
751
38%
1157
April21st to endNight
49%
734
27%
1874
14%
734
55%
734
40%
1120
May1st to 10thNight
53%
564
24%
2800
14%
559
58%
559
22%
1498
May11th to 20thNight
53%
552
17%
2759
11%
541
58%
541
19%
1548
May21st to endNight
66%
597
15%
3034
15%
593
69%
593
23%
1460
June1st to 10thNight
64%
570
16%
1710
13%
570
66%
570
26%
1116
June11th to 20thNight
66%
570
13%
1710
12%
570
67%
570
28%
1107
June21st to endNight
68%
570
13%
1710
11%
570
69%
570
27%
1106
July1st to 10thNight
67%
542
11%
2706
10%
535
69%
535
14%
1879
July11th to 20thNight
70%
536
7%
2752
9%
533
70%
533
14%
1883
July21st to endNight
71%
610
8%
2957
12%
569
74%
569
13%
2176
August1st to 10thNight
67%
557
7%
2789
11%
545
68%
545
12%
2011
August11th to 20thNight
66%
543
8%
2627
9%
543
66%
543
14%
1667
August21st to endNight
64%
818
18%
2993
11%
814
64%
814
23%
1603
September1st to 10thNight
67%
760
19%
2043
16%
760
68%
760
30%
1341
September11th to 20thNight
60%
760
18%
2090
16%
760
61%
760
25%
1451
September21st to endNight
55%
760
17%
2090
15%
760
57%
760
26%
1428
October1st to 10thNight
59%
760
20%
2828
25%
740
64%
740
24%
1835
October11th to 20thNight
56%
760
30%
2231
27%
740
65%
740
37%
1259
October21st to endNight
56%
836
27%
2830
27%
814
65%
814
31%
1664
November1st to 10thNight
53%
780
28%
2341
24%
780
60%
780
35%
1357
November11th to 20thNight
45%
763
29%
2322
22%
763
55%
763
32%
1364
November21st to endNight
45%
760
26%
2470
19%
760
56%
760
29%
1434
December1st to 10thNight
38%
760
24%
2470
14%
760
50%
760
24%
1553
December11th to 20thNight
41%
759
26%
2927
19%
758
51%
758
24%
1686
December21st to endNight
35%
829
16%
4411
16%
817
45%
817
14%
2566

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
12%6%26%5%5%5%46%8%41%
101220
Night
12%6%26%44446%8%43%
97892
TransparencyDay
39%6%12%19%18%6%
104910
Night
38%5%12%19%18%8%
102341
SeeingDay
13%6%20%24%22%14%
15469
Night
14%6%22%33%22%3
25539

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
14%6%25%43435%7%47%
2836
11th to 20thDay
11%6%25%43325%6%51%
2840
21st to endDay
14%8%28%5%4434444%
3124
February1st to 10thDay
14%8%25%44446%7%41%
1710
11th to 20thDay
18%6%26%324445%46%
1832
21st to endDay
16%8%25%444346%43%
1672
March1st to 10thDay
20%10%37%44335%5%35%
3435
11th to 20thDay
9%415%44435%8%52%
3480
21st to endDay
17%7%36%43435%6%43%
3815
April1st to 10thDay
9%415%5%4446%7%50%
2090
11th to 20thDay
10%6%16%345%45%6%50%
2254
21st to endDay
8%425%445%46%8%51%
2321
May1st to 10thDay
8%6%27%5%5%5%47%8%42%
4082
11th to 20thDay
15%8%36%5%4445%7%38%
4081
21st to endDay
6%415%445%5%7%10%47%
4476
June1st to 10thDay
11%6%38%6%5%5%6%8%9%34%
2470
11th to 20thDay
7%5%25%6%5%6%6%8%9%42%
2470
21st to endDay
4427%7%7%7%5%7%10%38%
2470
July1st to 10thDay
13%7%39%6%7%7%6%7%10%24%
4120
11th to 20thDay
6%6%28%7%8%8%7%10%12%27%
4120
21st to endDay
9%8%39%7%7%8%6%8%13%23%
4466
August1st to 10thDay
21%6%27%6%6%6%6%8%11%21%
4104
11th to 20thDay
9%5%38%6%6%7%5%8%11%33%
3998
21st to endDay
8%5%27%5%5%6%5%8%11%39%
4180
September1st to 10thDay
9%7%26%6%6%5%5%6%9%40%
2131
11th to 20thDay
14%6%27%5%5%5%45%7%39%
2090
21st to endDay
16%6%26%35%445%8%40%
2090
October1st to 10thDay
13%6%26%444347%48%
1957
11th to 20thDay
9%5%25%333345%58%
1900
21st to endDay
10%425%333345%58%
2090
November1st to 10thDay
13%5%2433336%6%53%
1957
11th to 20thDay
14%7%25%433336%50%
1862
21st to endDay
14%5%25%43335%7%48%
1710
December1st to 10thDay
15%8%26%45%5%36%6%40%
1710
11th to 20thDay
16%5%2442335%6%51%
2153
21st to endDay
19%8%25%333346%44%
3124
January1st to 10thNight
15%7%25%44445%6%46%
4109
11th to 20thNight
10%6%37%45%5%46%8%42%
4120
21st to endNight
13%8%37%44435%5%45%
4532
February1st to 10thNight
17%6%16%44435%7%44%
2470
11th to 20thNight
17%7%26%443346%44%
2232
21st to endNight
13%6%26%5%4436%6%45%
1780
March1st to 10thNight
22%11%46%443346%33%
3418
11th to 20thNight
11%426%44346%7%50%
3480
21st to endNight
15%5%25%44445%8%45%
3817
April1st to 10thNight
10%5%25%44435%7%51%
2088
11th to 20thNight
11%6%2443435%9%50%
1875
21st to endNight
7%5%25%44435%7%54%
1874
May1st to 10thNight
7%6%26%5%45%47%9%44%
2813
11th to 20thNight
13%6%26%45%437%8%43%
2812
21st to endNight
6%325%5%5%5%47%10%48%
3079
June1st to 10thNight
9%7%36%5%46%6%9%10%35%
1710
11th to 20thNight
9%427%5%5%5%5%7%11%39%
1710
21st to endNight
6%5%26%6%5%6%6%10%13%35%
1710
July1st to 10thNight
12%8%39%5%6%5%5%7%10%28%
2840
11th to 20thNight
7%6%38%7%6%7%5%10%13%28%
2840
21st to endNight
10%9%39%7%6%7%6%9%10%24%
3087
August1st to 10thNight
20%7%27%6%5%6%5%8%10%23%
2825
11th to 20thNight
9%6%28%46%7%6%8%10%35%
2785
21st to endNight
6%424445%5%8%11%47%
3476
September1st to 10thNight
8%5%27%6%5%5%5%7%11%39%
2043
11th to 20thNight
11%7%38%6%6%446%9%36%
2090
21st to endNight
17%7%36%5%4436%7%39%
2090
October1st to 10thNight
12%6%25%433346%52%
2222
11th to 20thNight
11%42433335%5%58%
2280
21st to endNight
8%6%2433335%6%57%
2508
November1st to 10thNight
13%5%25%333345%54%
2341
11th to 20thNight
15%6%3433325%5%51%
2322
21st to endNight
12%6%35%33435%7%47%
2470
December1st to 10thNight
16%7%26%345%36%7%42%
2470
11th to 20thNight
17%6%25%433245%50%
3042
21st to endNight
18%8%26%34445%7%40%
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
37%46%23%23%7%
2837
11th to 20thDay
33%36%19%30%8%
2840
21st to endDay
44%4417%21%10%
3124
February1st to 10thDay
41%49%20%20%6%
1710
11th to 20thDay
41%36%18%24%7%
1842
21st to endDay
43%37%17%18%11%
1672
March1st to 10thDay
51%38%16%15%8%
3435
11th to 20thDay
30%410%17%26%13%
3480
21st to endDay
43%37%18%23%5%
3815
April1st to 10thDay
33%5%10%19%26%8%
2090
11th to 20thDay
35%38%22%20%12%
2254
21st to endDay
30%5%10%27%23%5%
2321
May1st to 10thDay
38%5%15%25%15%3
4120
11th to 20thDay
46%412%21%17%1
4085
21st to endDay
31%6%16%22%23%2
4489
June1st to 10thDay
44%7%16%21%11%1
2470
11th to 20thDay
34%8%17%26%13%1
2470
21st to endDay
37%10%19%21%12%2
2470
July1st to 10thDay
51%10%15%16%5%2
4055
11th to 20thDay
44%13%25%13%41
4051
21st to endDay
49%13%18%15%4
4324
August1st to 10thDay
55%9%21%12%3
4091
11th to 20thDay
40%11%17%22%10%
4037
21st to endDay
35%7%14%31%12%1
4180
September1st to 10thDay
40%9%15%17%15%5%
2131
11th to 20thDay
44%6%11%16%19%4
2090
21st to endDay
43%5%10%19%18%5%
2090
October1st to 10thDay
37%5%8%16%26%8%
3256
11th to 20thDay
18%25%16%31%28%
3140
21st to endDay
24%35%19%33%15%
3428
November1st to 10thDay
31%48%19%25%12%
1957
11th to 20thDay
38%26%19%25%11%
1862
21st to endDay
36%49%21%21%9%
1710
December1st to 10thDay
44%5%10%18%17%6%
1710
11th to 20thDay
36%36%22%25%8%
2150
21st to endDay
43%37%19%24%4
3124
January1st to 10thNight
39%5%6%18%23%9%
4109
11th to 20thNight
39%47%20%24%6%
4120
21st to endNight
42%47%12%26%9%
4532
February1st to 10thNight
41%38%18%22%8%
2470
11th to 20thNight
43%36%18%21%9%
2233
21st to endNight
39%411%17%17%12%
1780
March1st to 10thNight
53%39%14%14%7%
3418
11th to 20thNight
33%48%14%25%16%
3480
21st to endNight
39%39%22%18%8%
3817
April1st to 10thNight
34%5%10%18%22%10%
2088
11th to 20thNight
32%410%21%22%11%
1875
21st to endNight
29%5%11%26%22%6%
1874
May1st to 10thNight
35%5%17%26%13%3
2840
11th to 20thNight
39%5%16%22%18%1
2813
21st to endNight
29%7%16%27%19%2
3087
June1st to 10thNight
39%9%19%21%11%1
1710
11th to 20thNight
37%9%19%24%9%1
1710
21st to endNight
36%10%23%20%8%1
1710
July1st to 10thNight
48%9%18%18%42
2795
11th to 20thNight
43%15%26%12%41
2786
21st to endNight
51%11%19%14%4
2988
August1st to 10thNight
53%10%22%13%3
2814
11th to 20thNight
40%11%22%20%7%
2812
21st to endNight
28%7%18%37%9%1
3476
September1st to 10thNight
37%8%17%19%12%6%
2043
11th to 20thNight
44%8%12%17%16%3
2090
21st to endNight
44%6%13%19%15%4
2090
October1st to 10thNight
34%49%19%28%7%
3703
11th to 20thNight
18%35%14%25%35%
3779
21st to endNight
24%37%21%28%18%
4120
November1st to 10thNight
34%38%15%26%14%
2341
11th to 20thNight
36%37%17%25%13%
2322
21st to endNight
37%38%20%22%11%
2470
December1st to 10thNight
42%5%12%16%18%7%
2470
11th to 20thNight
38%36%18%26%8%
3044
21st to endNight
45%37%19%23%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
17%11%46%19%6%1
270
11th to 20thDay
13%11%39%26%10%1
270
21st to endDay
21%13%37%24%3
297
February1st to 10thDay
18%11%36%26%8%1
270
11th to 20thDay
28%11%39%17%5%
270
21st to endDay
16%15%39%24%42
327
March1st to 10thDay
17%11%29%27%15%1
460
11th to 20thDay
14%9%40%25%10%2
460
21st to endDay
16%9%36%25%11%2
506
April1st to 10thDay
13%13%30%28%12%3
460
11th to 20thDay
11%9%25%26%20%8%
452
21st to endDay
10%6%23%27%19%14%
460
May1st to 10thDay
6%10%28%27%19%11%
463
11th to 20thDay
15%214%26%27%16%
487
21st to endDay
12%313%23%25%25%
529
June1st to 10thDay
12%310%24%32%18%
490
11th to 20thDay
8%312%25%26%27%
490
21st to endDay
7%18%28%31%24%
490
July1st to 10thDay
9%2416%32%36%
485
11th to 20thDay
9%1416%35%35%
484
21st to endDay
6%36%19%40%25%
532
August1st to 10thDay
14%38%17%34%25%
486
11th to 20thDay
10%3419%33%32%
479
21st to endDay
16%26%17%33%27%
539
September1st to 10thDay
9%38%24%34%22%
490
11th to 20thDay
15%48%25%32%15%
490
21st to endDay
19%310%25%28%15%
490
October1st to 10thDay
15%219%30%22%11%
490
11th to 20thDay
10%419%30%26%10%
490
21st to endDay
12%420%30%26%8%
539
November1st to 10thDay
17%422%30%19%8%
495
11th to 20thDay
19%5%32%30%12%3
422
21st to endDay
11%9%29%29%17%5%
270
December1st to 10thDay
20%7%31%30%11%1
270
11th to 20thDay
20%10%31%27%8%3
270
21st to endDay
22%10%32%20%12%3
297
January1st to 10thNight
17%10%36%31%6%
760
11th to 20thNight
16%12%30%33%9%
760
21st to endNight
17%10%39%31%2
836
February1st to 10thNight
20%8%32%34%6%
760
11th to 20thNight
21%10%36%30%3
743
21st to endNight
15%11%38%30%5%
628
March1st to 10thNight
15%8%34%34%9%
760
11th to 20thNight
15%9%35%33%9%
760
21st to endNight
14%9%33%34%9%
836
April1st to 10thNight
13%12%31%34%10%
760
11th to 20thNight
13%9%26%36%14%1
751
21st to endNight
10%6%28%41%14%1
734
May1st to 10thNight
8%427%43%17%1
570
11th to 20thNight
12%422%38%21%3
561
21st to endNight
10%29%38%35%6%
617
June1st to 10thNight
12%210%41%30%5%
570
11th to 20thNight
12%19%32%37%10%
570
21st to endNight
7%18%36%39%9%
570
July1st to 10thNight
10%3428%47%7%
555
11th to 20thNight
8%1428%50%9%
552
21st to endNight
8%2334%44%8%
624
August1st to 10thNight
10%2429%45%10%
567
11th to 20thNight
10%2330%47%7%
564
21st to endNight
14%35%27%43%9%
836
September1st to 10thNight
9%36%31%44%7%
760
11th to 20thNight
14%39%31%35%7%
760
21st to endNight
21%211%30%32%4
760
October1st to 10thNight
16%315%33%29%5%
760
11th to 20thNight
13%5%20%34%25%3
760
21st to endNight
11%5%21%33%27%3
836
November1st to 10thNight
16%5%21%35%20%3
780
11th to 20thNight
19%6%25%35%14%1
763
21st to endNight
14%6%28%33%17%2
760
December1st to 10thNight
19%6%29%32%13%
760
11th to 20thNight
17%8%27%34%13%1
760
21st to endNight
22%9%26%32%10%1
836
Page generated at 2024-11-08 06:44:45. Version ac07

Copyright © 2024 Attilla Danko.


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