Siloam Springs
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Siloam Springs clear sky chart from 2005-11-06 to 2024-02-20.

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
44%
24434
25%
79780
17%
24328
53%
24328
30%
46420

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
29%
941
23%
4020
9%
926
41%
926
19%
2459
January11th to 20thNight
25%
950
24%
3997
8%
930
37%
930
22%
2112
January21st to endNight
29%
1035
19%
4489
10%
1023
41%
1023
19%
2841
February1st to 10thNight
25%
950
21%
2470
6%
950
34%
950
28%
1653
February11th to 20thNight
23%
913
21%
2384
6%
909
31%
909
28%
1537
February21st to endNight
22%
476
28%
1660
10%
476
40%
476
21%
997
March1st to 10thNight
31%
540
26%
1980
16%
540
44%
540
24%
1162
March11th to 20thNight
34%
540
20%
1980
14%
540
44%
540
22%
1215
March21st to endNight
27%
594
20%
2178
11%
594
40%
594
21%
1327
April1st to 10thNight
31%
540
25%
1900
15%
540
45%
540
29%
1047
April11th to 20thNight
35%
533
25%
1775
16%
533
50%
533
28%
1038
April21st to endNight
29%
540
22%
1769
11%
540
45%
540
27%
1080
May1st to 10thNight
45%
540
22%
1620
19%
540
52%
540
31%
992
May11th to 20thNight
50%
531
21%
1594
19%
531
56%
531
32%
950
May21st to endNight
48%
584
18%
1746
12%
582
58%
582
32%
1078
June1st to 10thNight
71%
540
22%
1620
21%
540
74%
540
45%
840
June11th to 20thNight
66%
540
24%
1620
22%
540
70%
540
48%
824
June21st to endNight
75%
540
27%
1620
24%
540
79%
540
54%
787
July1st to 10thNight
75%
525
20%
1575
20%
525
77%
525
41%
867
July11th to 20thNight
79%
522
25%
1566
28%
522
81%
522
52%
772
July21st to endNight
78%
591
28%
1673
33%
558
79%
558
46%
876
August1st to 10thNight
77%
537
25%
1601
27%
534
80%
534
45%
839
August11th to 20thNight
76%
534
29%
1604
33%
534
78%
534
40%
894
August21st to endNight
78%
594
28%
1980
34%
594
79%
594
43%
984
September1st to 10thNight
73%
540
29%
1800
31%
540
76%
540
41%
911
September11th to 20thNight
67%
540
29%
1978
30%
540
71%
540
33%
1038
September21st to endNight
64%
540
34%
1980
32%
540
70%
540
40%
941
October1st to 10thNight
60%
710
31%
2150
22%
710
66%
710
45%
1101
October11th to 20thNight
44%
720
32%
2160
18%
720
54%
720
38%
1195
October21st to endNight
41%
792
28%
2376
17%
792
49%
792
32%
1403
November1st to 10thNight
39%
740
33%
2220
16%
740
55%
740
40%
1195
November11th to 20thNight
37%
831
30%
2351
15%
831
49%
831
38%
1350
November21st to endNight
34%
950
28%
2470
12%
950
45%
950
34%
1528
December1st to 10thNight
31%
950
25%
2523
9%
950
43%
950
30%
1614
December11th to 20thNight
28%
949
25%
2899
10%
948
38%
948
24%
1891
December21st to endNight
27%
1042
16%
4452
9%
1026
39%
1026
15%
3082

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
13%7%35%5%3445%7%45%
78722
Night
12%6%35%42445%6%50%
80456
TransparencyDay
39%311%25%18%4
78446
Night
36%311%25%21%5%
80252
SeeingDay
15%8%25%27%19%6%
14416
Night
15%8%28%33%15%1
24457

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
15%12%34422335%46%
2847
11th to 20thDay
10%7%27%5%23336%52%
2850
21st to endDay
22%10%2441234444%
3135
February1st to 10thDay
16%10%36%6%3344440%
1710
11th to 20thDay
15%9%45%42335%6%43%
1684
21st to endDay
19%9%35%5%33445%41%
1594
March1st to 10thDay
14%8%34434447%44%
1980
11th to 20thDay
20%8%35%43445%440%
1980
21st to endDay
20%8%46%5%345%45%35%
2178
April1st to 10thDay
12%7%25%5%45%45%7%44%
2060
11th to 20thDay
17%7%35%6%345%46%42%
2134
21st to endDay
18%8%37%4345%5%5%39%
2186
May1st to 10thDay
17%6%36%6%345%5%5%39%
2340
11th to 20thDay
14%7%37%5%345%6%7%40%
2302
21st to endDay
12%5%36%7%45%6%6%9%38%
2531
June1st to 10thDay
8%426%435%5%7%9%46%
2340
11th to 20thDay
8%5%24435%6%7%9%48%
2340
21st to endDay
5%2245%35%5%6%8%56%
2340
July1st to 10thDay
9%5%25%6%46%7%7%11%39%
2340
11th to 20thDay
43245%35%6%7%10%52%
2340
21st to endDay
7%425%5%45%6%7%11%44%
2546
August1st to 10thDay
7%425%4346%8%10%47%
2328
11th to 20thDay
9%425%5%45%6%6%8%46%
2295
21st to endDay
6%425%5%35%5%6%9%52%
2376
September1st to 10thDay
12%424423448%53%
2158
11th to 20thDay
12%5%15%435%5%6%8%46%
1980
21st to endDay
7%323435%46%8%54%
1972
October1st to 10thDay
10%42442345%6%55%
1800
11th to 20thDay
14%5%24322336%57%
1800
21st to endDay
18%5%25%42333450%
1980
November1st to 10thDay
11%5%235%23337%58%
1858
11th to 20thDay
12%7%25%42444453%
1826
21st to endDay
17%7%34224437%47%
1710
December1st to 10thDay
13%8%36%5%34345%46%
1586
11th to 20thDay
14%10%36%6%34345%43%
2161
21st to endDay
16%15%7%5%42445%6%31%
3135
January1st to 10thNight
12%9%5%6%5%33445%43%
4108
11th to 20thNight
11%6%25%425%445%52%
4120
21st to endNight
22%10%46%32223443%
4532
February1st to 10thNight
15%10%36%32445%6%44%
2470
11th to 20thNight
15%8%35%423346%48%
2383
21st to endNight
16%8%35%424346%45%
1660
March1st to 10thNight
13%7%26%4245%5%6%47%
1980
11th to 20thNight
18%7%34424446%44%
1980
21st to endNight
16%7%36%5%23446%44%
2178
April1st to 10thNight
12%6%2433445%6%52%
1900
11th to 20thNight
13%7%25%33445%6%48%
1775
21st to endNight
17%6%24434446%46%
1769
May1st to 10thNight
12%7%2443445%7%47%
1620
11th to 20thNight
12%5%244245%5%8%47%
1593
21st to endNight
11%435%5%35%6%7%11%42%
1745
June1st to 10thNight
6%31433345%9%58%
1620
11th to 20thNight
5%21342446%11%58%
1620
21st to endNight
321332446%8%65%
1620
July1st to 10thNight
5%3335%35%5%6%11%51%
1620
11th to 20thNight
32133335%6%9%62%
1620
21st to endNight
42245%245%7%10%55%
1772
August1st to 10thNight
4223425%5%7%12%53%
1611
11th to 20thNight
7%3144346%5%8%54%
1604
21st to endNight
33145%35%46%8%59%
1980
September1st to 10thNight
8%41343445%7%58%
1800
11th to 20thNight
9%425%4245%5%6%54%
1978
21st to endNight
8%5%1342325%8%59%
1980
October1st to 10thNight
7%314324447%61%
2150
11th to 20thNight
13%423323346%57%
2160
21st to endNight
18%6%23323235%53%
2376
November1st to 10thNight
11%5%23323335%62%
2220
11th to 20thNight
11%6%24323345%57%
2351
21st to endNight
15%7%23413345%52%
2470
December1st to 10thNight
13%9%35%324345%48%
2523
11th to 20thNight
13%9%37%5%23345%45%
3036
21st to endNight
16%13%7%6%42334436%
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
43%25%27%21%2
2848
11th to 20thDay
36%214%27%17%4
2850
21st to endDay
47%17%22%18%5%
3135
February1st to 10thDay
48%38%22%14%4
1710
11th to 20thDay
44%28%25%17%3
1693
21st to endDay
47%27%21%15%8%
1594
March1st to 10thDay
42%37%20%19%9%
1980
11th to 20thDay
48%38%22%14%4
1980
21st to endDay
51%411%21%12%2
2178
April1st to 10thDay
39%412%24%17%3
2060
11th to 20thDay
45%311%21%16%3
2134
21st to endDay
48%49%23%15%1
2186
May1st to 10thDay
47%410%21%16%1
2340
11th to 20thDay
44%313%25%14%
2306
21st to endDay
43%5%16%24%11%
2531
June1st to 10thDay
34%5%16%29%15%2
2340
11th to 20thDay
31%5%16%30%16%2
2340
21st to endDay
25%415%31%20%4
2340
July1st to 10thDay
36%6%18%26%13%1
2276
11th to 20thDay
24%5%16%33%18%3
2271
21st to endDay
32%5%17%32%13%1
2405
August1st to 10thDay
31%5%19%30%14%2
2314
11th to 20thDay
35%5%12%27%19%2
2295
21st to endDay
30%414%30%17%5%
2376
September1st to 10thDay
32%410%27%19%8%
2158
11th to 20thDay
35%5%9%23%24%4
1980
21st to endDay
28%410%26%27%5%
1972
October1st to 10thDay
31%311%26%23%6%
1800
11th to 20thDay
31%26%24%29%8%
1800
21st to endDay
40%28%26%17%7%
1980
November1st to 10thDay
29%29%28%23%8%
1858
11th to 20thDay
36%26%25%22%10%
1826
21st to endDay
39%38%22%25%4
1710
December1st to 10thDay
42%28%27%18%3
1586
11th to 20thDay
46%25%21%23%3
2159
21st to endDay
56%27%19%13%2
3135
January1st to 10thNight
44%28%23%20%3
4108
11th to 20thNight
36%215%23%22%2
4120
21st to endNight
47%29%19%19%4
4532
February1st to 10thNight
43%310%23%16%5%
2470
11th to 20thNight
40%27%27%19%4
2384
21st to endNight
42%27%20%21%7%
1660
March1st to 10thNight
39%48%20%20%10%
1980
11th to 20thNight
43%311%21%17%5%
1980
21st to endNight
43%39%27%15%3
2178
April1st to 10thNight
35%210%26%20%6%
1900
11th to 20thNight
37%39%24%20%6%
1775
21st to endNight
40%410%25%20%2
1769
May1st to 10thNight
37%412%25%19%3
1620
11th to 20thNight
34%5%16%25%17%2
1594
21st to endNight
35%7%18%26%13%1
1746
June1st to 10thNight
24%417%32%19%3
1620
11th to 20thNight
22%5%15%34%22%3
1620
21st to endNight
18%416%31%24%6%
1620
July1st to 10thNight
26%7%16%31%19%1
1575
11th to 20thNight
19%414%32%27%3
1566
21st to endNight
23%5%15%37%19%1
1673
August1st to 10thNight
23%6%17%35%18%1
1601
11th to 20thNight
28%5%12%25%26%4
1604
21st to endNight
24%414%29%24%6%
1980
September1st to 10thNight
26%49%31%22%9%
1800
11th to 20thNight
31%410%24%26%6%
1978
21st to endNight
26%28%27%31%6%
1980
October1st to 10thNight
24%312%25%28%8%
2150
11th to 20thNight
31%26%22%29%9%
2160
21st to endNight
37%27%23%23%9%
2376
November1st to 10thNight
28%28%26%27%9%
2220
11th to 20thNight
31%37%25%26%8%
2351
21st to endNight
36%28%21%26%6%
2470
December1st to 10thNight
40%210%24%21%3
2523
11th to 20thNight
44%26%23%21%4
3037
21st to endNight
54%28%19%14%3
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
24%13%39%18%6%
270
11th to 20thDay
20%22%39%17%11
270
21st to endDay
19%19%40%17%5%
297
February1st to 10thDay
27%15%38%17%3
270
11th to 20thDay
25%22%35%15%3
267
21st to endDay
34%19%33%12%2
198
March1st to 10thDay
24%18%36%20%3
240
11th to 20thDay
28%17%32%20%5%
240
21st to endDay
28%17%39%11%31
264
April1st to 10thDay
18%19%35%20%6%2
320
11th to 20thDay
24%15%33%20%8%1
412
21st to endDay
24%13%34%19%9%1
446
May1st to 10thDay
19%11%35%27%7%
603
11th to 20thDay
16%8%30%29%13%3
625
21st to endDay
11%5%32%27%17%7%
679
June1st to 10thDay
11%316%33%28%9%
630
11th to 20thDay
9%316%39%26%7%
630
21st to endDay
4221%38%28%7%
630
July1st to 10thDay
9%211%30%33%14%
621
11th to 20thDay
6%12%33%37%11%
618
21st to endDay
8%27%31%36%16%
684
August1st to 10thDay
9%19%39%33%9%
626
11th to 20thDay
11%19%32%36%10%
609
21st to endDay
7%28%31%41%11%
495
September1st to 10thDay
11%29%33%34%11%
448
11th to 20thDay
7%13%43%25%12%
270
21st to endDay
9%5%21%31%25%10%
270
October1st to 10thDay
11%6%32%26%19%6%
270
11th to 20thDay
15%12%36%28%9%
270
21st to endDay
27%15%30%21%6%2
297
November1st to 10thDay
13%9%43%25%8%2
270
11th to 20thDay
17%15%37%21%9%1
270
21st to endDay
24%15%33%21%7%
270
December1st to 10thDay
20%11%44%16%7%2
270
11th to 20thDay
23%12%40%17%6%1
270
21st to endDay
25%17%41%14%3
297
January1st to 10thNight
18%15%32%30%5%
950
11th to 20thNight
19%15%37%23%5%
950
21st to endNight
16%12%37%30%4
1045
February1st to 10thNight
20%13%38%25%4
950
11th to 20thNight
20%15%39%23%3
913
21st to endNight
23%13%38%24%3
476
March1st to 10thNight
18%11%37%29%5%
540
11th to 20thNight
22%10%31%32%5%
540
21st to endNight
19%11%39%25%6%
594
April1st to 10thNight
16%11%40%28%5%
540
11th to 20thNight
16%10%34%30%9%
533
21st to endNight
21%5%41%23%9%1
540
May1st to 10thNight
16%6%29%39%10%
540
11th to 20thNight
16%424%38%17%1
531
21st to endNight
12%428%32%22%2
584
June1st to 10thNight
7%412%41%35%1
540
11th to 20thNight
5%121%46%26%1
540
21st to endNight
3117%46%31%3
540
July1st to 10thNight
7%28%39%40%5%
525
11th to 20thNight
49%39%41%6%
522
21st to endNight
5%26%38%44%5%
591
August1st to 10thNight
418%45%39%4
537
11th to 20thNight
8%17%46%33%4
534
21st to endNight
417%39%42%5%
594
September1st to 10thNight
10%110%42%35%2
540
11th to 20thNight
11%110%42%31%4
540
21st to endNight
11%218%38%28%4
540
October1st to 10thNight
8%223%37%25%4
710
11th to 20thNight
15%6%30%37%11%
720
21st to endNight
22%7%27%32%10%1
792
November1st to 10thNight
13%7%37%30%12%
740
11th to 20thNight
15%10%35%31%8%
831
21st to endNight
20%10%33%29%9%
950
December1st to 10thNight
19%12%33%30%6%
950
11th to 20thNight
22%11%34%28%5%
950
21st to endNight
21%13%35%27%4
1045
Page generated at 2024-02-17 05:28:38. Version ac07

Copyright 2024 Attilla Danko


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