Table Rock State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Table Rock State Park clear sky chart from 2005-11-05 to 2019-06-02.

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%
17915
22%
53830
15%
17872
57%
17872
27%
34243

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 15thNight
35%
840
24%
2717
14%
836
48%
836
25%
1666
January16th to endNight
32%
896
26%
2912
15%
896
47%
896
26%
1753
February1st to 15thNight
33%
824
26%
2528
13%
821
47%
821
28%
1529
February16th to endNight
30%
735
23%
2205
13%
735
41%
735
24%
1421
March1st to 15thNight
36%
840
25%
2349
14%
840
45%
840
27%
1527
March16th to endNight
38%
896
19%
2464
10%
896
45%
896
27%
1603
April1st to 15thNight
43%
837
24%
2305
14%
837
51%
837
32%
1425
April16th to endNight
50%
624
25%
1880
16%
624
57%
624
31%
1143
May1st to 15thNight
54%
630
17%
1890
11%
630
58%
630
26%
1235
May16th to endNight
61%
657
17%
1971
13%
657
63%
657
26%
1287
June1st to 15thNight
67%
588
14%
1765
12%
588
68%
588
25%
1165
June16th to endNight
73%
585
14%
1755
12%
585
74%
585
30%
1133
July1st to 15thNight
67%
555
10%
1665
8%
555
68%
555
22%
1186
July16th to endNight
72%
612
12%
1739
10%
579
74%
579
24%
1196
August1st to 15thNight
65%
575
13%
1715
12%
572
66%
572
21%
1209
August16th to endNight
66%
656
16%
2002
15%
656
67%
656
23%
1363
September1st to 15thNight
62%
780
15%
2145
13%
780
63%
780
24%
1494
September16th to endNight
56%
777
20%
2145
15%
777
60%
777
27%
1461
October1st to 15thNight
54%
780
28%
2223
25%
780
60%
780
32%
1363
October16th to endNight
55%
832
32%
2496
26%
832
66%
832
37%
1394
November1st to 15thNight
53%
820
28%
2587
24%
820
61%
820
32%
1497
November16th to endNight
50%
840
28%
2730
22%
840
60%
840
32%
1556
December1st to 15thNight
43%
840
24%
2730
16%
840
54%
840
23%
1729
December16th to endNight
37%
896
22%
2912
15%
896
46%
896
22%
1908

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%424435%5%5%7%42%
54502
Night
15%42442445%7%44%
54028
TransparencyDay
39%7%12%19%16%4
54203
Night
38%6%11%19%18%5%
53831
SeeingDay
17%7%20%24%18%11%
7709
Night
16%5%20%30%21%4
17917

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 15thDay
18%5%34223235%47%
1881
16th to endDay
16%413323435%51%
2016
February1st to 15thDay
15%5%14324446%46%
1991
16th to endDay
20%414423335%44%
1840
March1st to 15thDay
19%412333346%46%
2271
16th to endDay
17%5%2432445%7%42%
2463
April1st to 15thDay
14%3234245%6%8%44%
2314
16th to endDay
14%414435%446%47%
2684
May1st to 15thDay
13%4235%35%5%6%7%40%
2721
16th to endDay
13%425%5%346%7%8%38%
2847
June1st to 15thDay
10%4246%47%7%8%10%32%
2548
16th to endDay
5%215%7%37%6%9%11%37%
2535
July1st to 15thDay
10%5%25%6%47%7%8%10%29%
2535
16th to endDay
8%425%6%5%7%7%8%12%31%
2673
August1st to 15thDay
14%5%245%47%7%8%10%29%
2487
16th to endDay
12%425%5%45%7%7%10%33%
2535
September1st to 15thDay
11%5%25%6%46%7%7%8%34%
2145
16th to endDay
16%5%245%345%5%7%38%
2145
October1st to 15thDay
15%413312335%55%
2067
16th to endDay
12%31322223460%
2080
November1st to 15thDay
15%32332333454%
1928
16th to endDay
15%323213346%52%
1890
December1st to 15thDay
20%5%24324345%43%
1890
16th to endDay
24%6%2441233441%
2016
January1st to 15thNight
19%324423235%48%
2717
16th to endNight
17%5%14323345%48%
2912
February1st to 15thNight
15%423423345%50%
2519
16th to endNight
17%414423446%44%
2205
March1st to 15thNight
16%6%1432345%446%
2349
16th to endNight
17%42442335%6%45%
2464
April1st to 15thNight
14%424323347%49%
2305
16th to endNight
14%324423346%49%
1880
May1st to 15thNight
12%5%35%5%345%48%41%
1889
16th to endNight
12%5%2443446%8%42%
1970
June1st to 15thNight
8%3246%45%7%8%11%36%
1765
16th to endNight
7%3145%35%7%6%12%41%
1755
July1st to 15thNight
9%425%7%38%7%8%10%32%
1755
16th to endNight
6%426%6%45%7%9%12%33%
1847
August1st to 15thNight
14%415%6%36%6%7%9%34%
1726
16th to endNight
11%6%25%5%45%6%6%11%34%
2002
September1st to 15thNight
11%5%26%5%35%6%6%9%36%
2145
16th to endNight
18%4245%3445%7%39%
2145
October1st to 15thNight
15%413423345%51%
2223
16th to endNight
12%31332343458%
2496
November1st to 15thNight
15%313322235%54%
2587
16th to endNight
16%312213435%53%
2730
December1st to 15thNight
18%5%14334445%44%
2730
16th to endNight
22%5%2442335%5%40%
2912

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 15thDay
40%47%19%21%6%
1882
16th to endDay
36%37%22%22%9%
2016
February1st to 15thDay
39%48%21%20%5%
1993
16th to endDay
42%48%19%17%6%
1840
March1st to 15thDay
39%47%20%20%7%
2271
16th to endDay
40%7%10%21%16%3
2464
April1st to 15thDay
35%6%12%21%18%5%
2314
16th to endDay
36%6%10%21%18%6%
2684
May1st to 15thDay
39%9%13%19%15%2
2721
16th to endDay
39%10%14%21%12%1
2851
June1st to 15thDay
40%13%18%20%7%
2548
16th to endDay
34%13%17%21%11%2
2535
July1st to 15thDay
43%12%18%15%7%2
2396
16th to endDay
38%14%20%17%6%1
2518
August1st to 15thDay
45%12%15%17%7%
2474
16th to endDay
42%12%17%18%8%1
2535
September1st to 15thDay
42%11%14%15%13%2
2145
16th to endDay
42%7%12%16%17%3
2145
October1st to 15thDay
33%411%20%25%5%
2067
16th to endDay
28%35%22%27%11%
2080
November1st to 15thDay
34%38%18%27%9%
1928
16th to endDay
33%5%6%20%25%8%
1890
December1st to 15thDay
44%48%18%18%5%
1890
16th to endDay
47%39%19%15%5%
2016
January1st to 15thNight
39%48%15%24%6%
2717
16th to endNight
39%35%20%23%7%
2912
February1st to 15thNight
36%48%22%22%6%
2528
16th to endNight
40%5%8%19%20%4
2205
March1st to 15thNight
38%6%7%17%20%9%
2349
16th to endNight
40%5%10%19%20%4
2464
April1st to 15thNight
36%48%23%22%4
2305
16th to endNight
35%5%9%21%20%7%
1880
May1st to 15thNight
39%8%13%20%16%2
1890
16th to endNight
38%8%12%24%12%2
1972
June1st to 15thNight
37%11%18%23%7%1
1765
16th to endNight
32%12%19%19%12%2
1755
July1st to 15thNight
41%13%19%15%8%1
1665
16th to endNight
36%15%21%17%6%2
1739
August1st to 15thNight
42%12%17%14%11%
1715
16th to endNight
41%10%19%19%8%1
2002
September1st to 15thNight
42%10%15%18%11%2
2145
16th to endNight
42%7%11%17%16%4
2145
October1st to 15thNight
34%5%11%18%23%6%
2223
16th to endNight
29%45%20%28%11%
2496
November1st to 15thNight
34%36%17%27%10%
2587
16th to endNight
32%46%19%27%9%
2730
December1st to 15thNight
42%48%18%18%7%
2730
16th to endNight
45%49%16%18%5%
2912

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 15thDay
23%13%37%21%3
180
16th to endDay
17%27%36%12%5%
192
February1st to 15thDay
20%21%42%13%1
180
16th to endDay
33%15%37%11%1
159
March1st to 15thDay
22%15%29%24%6%
351
16th to endDay
19%13%32%23%9%1
416
April1st to 15thDay
16%13%26%27%13%2
390
16th to endDay
17%7%25%27%17%5%
379
May1st to 15thDay
13%7%25%24%18%11%
408
16th to endDay
20%413%26%20%15%
459
June1st to 15thDay
8%312%27%27%20%
379
16th to endDay
8%214%25%23%25%
375
July1st to 15thDay
11%110%20%30%25%
365
16th to endDay
6%27%23%31%28%
390
August1st to 15thDay
22%18%20%22%24%
358
16th to endDay
14%110%20%30%22%
396
September1st to 15thDay
14%210%23%30%18%
375
16th to endDay
20%213%23%29%10%
374
October1st to 15thDay
20%317%27%22%9%
375
16th to endDay
13%8%17%36%20%4
400
November1st to 15thDay
28%8%21%26%12%1
256
16th to endDay
11%8%34%31%11%2
180
December1st to 15thDay
27%12%37%19%3
180
16th to endDay
32%14%36%15%2
192
January1st to 15thNight
20%9%30%32%7%
840
16th to endNight
20%9%33%32%4
896
February1st to 15thNight
17%9%34%32%4
824
16th to endNight
19%11%34%30%4
735
March1st to 15thNight
19%10%29%33%7%
840
16th to endNight
19%8%29%30%11%
896
April1st to 15thNight
16%10%26%31%14%
837
16th to endNight
14%5%23%33%20%1
624
May1st to 15thNight
14%319%33%26%2
630
16th to endNight
16%112%26%35%7%
659
June1st to 15thNight
9%19%29%40%10%
588
16th to endNight
8%18%27%41%12%
585
July1st to 15thNight
11%16%23%44%12%
555
16th to endNight
7%15%22%48%15%
612
August1st to 15thNight
18%16%22%39%11%
575
16th to endNight
12%17%22%44%11%
656
September1st to 15thNight
15%110%23%38%10%
780
16th to endNight
20%212%27%31%5%
777
October1st to 15thNight
17%5%17%25%25%8%
780
16th to endNight
13%5%19%35%21%4
832
November1st to 15thNight
17%319%35%19%4
820
16th to endNight
17%5%22%34%17%1
840
December1st to 15thNight
21%7%22%36%11%
840
16th to endNight
24%5%26%34%7%
896
Page generated at 2019-06-02 19:43:07. Version ac04

Copyright 2019 A. Danko


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