Smithville
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Smithville clear sky chart from 2005-11-06 to 2024-10-25.

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
46%
24396
20%
95191
16%
24205
52%
24205
21%
59041

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
25%
752
18%
4029
12%
737
36%
737
12%
2583
January11th to 20thNight
21%
760
20%
3991
9%
740
29%
740
9%
2661
January21st to endNight
22%
830
14%
4278
9%
814
35%
814
12%
2940
February1st to 10thNight
26%
760
18%
2280
11%
760
33%
760
19%
1628
February11th to 20thNight
20%
743
16%
2219
7%
740
28%
740
17%
1594
February21st to endNight
19%
628
18%
1884
8%
628
27%
628
17%
1365
March1st to 10thNight
30%
757
15%
3712
11%
745
37%
745
12%
2620
March11th to 20thNight
27%
754
23%
3498
9%
740
34%
740
17%
1840
March21st to endNight
33%
805
13%
3652
9%
790
39%
790
15%
2298
April1st to 10thNight
41%
570
26%
1900
18%
570
52%
570
27%
1111
April11th to 20thNight
40%
563
27%
1875
18%
563
52%
563
29%
1110
April21st to endNight
43%
570
22%
1802
16%
570
50%
570
28%
1110
May1st to 10thNight
44%
565
19%
2768
13%
559
52%
559
18%
1711
May11th to 20thNight
54%
550
16%
2780
14%
541
57%
541
16%
1706
May21st to endNight
65%
601
16%
3030
15%
593
68%
593
19%
1700
June1st to 10thNight
63%
570
19%
1710
16%
570
66%
570
30%
1059
June11th to 20thNight
76%
570
20%
1710
17%
570
77%
570
43%
921
June21st to endNight
74%
570
20%
1556
16%
570
75%
570
36%
965
July1st to 10thNight
68%
539
15%
2528
13%
535
69%
535
19%
1499
July11th to 20thNight
73%
535
16%
2572
18%
533
74%
533
22%
1442
July21st to endNight
69%
613
11%
2968
18%
569
72%
569
14%
2228
August1st to 10thNight
73%
548
29%
2508
20%
544
73%
544
25%
1251
August11th to 20thNight
70%
548
14%
2806
20%
543
71%
543
22%
1464
August21st to endNight
73%
607
19%
2970
24%
605
73%
605
25%
1428
September1st to 10thNight
68%
629
23%
1959
24%
629
68%
629
29%
1195
September11th to 20thNight
60%
760
22%
2090
19%
760
62%
760
31%
1346
September21st to endNight
61%
760
28%
2090
22%
760
65%
760
37%
1257
October1st to 10thNight
63%
760
34%
2090
28%
760
67%
760
42%
1190
October11th to 20thNight
50%
760
28%
2130
21%
760
57%
760
34%
1292
October21st to endNight
48%
812
28%
2591
25%
812
55%
812
30%
1528
November1st to 10thNight
53%
740
27%
2406
27%
740
59%
740
32%
1371
November11th to 20thNight
41%
760
28%
2470
21%
760
54%
760
31%
1429
November21st to endNight
40%
760
25%
2470
19%
760
49%
760
26%
1522
December1st to 10thNight
30%
760
17%
2470
13%
760
37%
760
17%
1747
December11th to 20thNight
33%
759
22%
2946
16%
758
43%
758
19%
1875
December21st to endNight
27%
828
13%
4453
10%
817
37%
817
10%
3055

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%8%37%5%45%46%8%38%
101112
Night
13%8%37%5%4435%7%41%
97645
TransparencyDay
43%6%10%22%15%3
100921
Night
42%5%10%22%17%3
97506
SeeingDay
16%8%21%23%20%11%
14803
Night
17%7%23%30%20%3
24566

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%5%11%5%5%6%45%5%26%
2836
11th to 20thDay
21%10%413%445%235%29%
2840
21st to endDay
22%13%6%6%34335%5%29%
3316
February1st to 10thDay
19%13%47%5%3334434%
1900
11th to 20thDay
21%11%48%5%43346%31%
1848
21st to endDay
21%10%38%5%4435%6%34%
1570
March1st to 10thDay
20%13%37%44335%6%31%
3120
11th to 20thDay
13%8%26%434346%46%
3411
21st to endDay
14%8%27%5%4446%6%39%
3891
April1st to 10thDay
12%7%27%44445%7%43%
2280
11th to 20thDay
13%8%37%44435%6%43%
2254
21st to endDay
12%8%37%6%45%46%7%39%
2375
May1st to 10thDay
17%7%36%5%45%46%8%35%
4082
11th to 20thDay
15%9%48%5%4435%7%34%
4081
21st to endDay
10%7%38%5%45%46%8%40%
4476
June1st to 10thDay
9%7%36%46%6%46%10%39%
2470
11th to 20thDay
45%26%5%5%6%5%7%11%44%
2470
21st to endDay
6%5%16%6%6%6%6%8%12%38%
2606
July1st to 10thDay
6%5%27%6%6%7%6%9%11%36%
4280
11th to 20thDay
9%6%27%5%6%6%5%7%10%36%
4120
21st to endDay
15%11%411%7%6%6%5%7%8%21%
4466
August1st to 10thDay
5%425%45%6%5%8%11%46%
4047
11th to 20thDay
5%5%27%5%5%6%5%9%12%38%
3729
21st to endDay
7%425%45%5%46%9%49%
4180
September1st to 10thDay
12%5%37%5%5%5%5%6%8%40%
2200
11th to 20thDay
14%7%36%445%35%6%42%
2090
21st to endDay
12%5%26%43445%6%47%
2090
October1st to 10thDay
11%425%44435%6%53%
2090
11th to 20thDay
12%5%15%443247%53%
2048
21st to endDay
15%6%25%33435%6%47%
1867
November1st to 10thDay
11%5%24423347%55%
1672
11th to 20thDay
14%8%25%33345%6%48%
1710
21st to endDay
15%9%35%34435%445%
1710
December1st to 10thDay
21%12%47%43335%6%32%
1710
11th to 20thDay
15%13%47%6%45%35%6%33%
2153
21st to endDay
18%13%5%7%5%3445%7%28%
3124
January1st to 10thNight
17%13%48%5%3435%6%34%
4109
11th to 20thNight
20%11%48%6%5%334434%
4120
21st to endNight
18%16%47%434346%31%
4336
February1st to 10thNight
20%9%49%44435%6%33%
2280
11th to 20thNight
23%10%38%444345%33%
2218
21st to endNight
23%11%37%44435%7%30%
1884
March1st to 10thNight
23%12%47%44435%5%30%
3733
11th to 20thNight
13%7%25%43435%6%48%
3548
21st to endNight
14%8%37%6%45%35%6%38%
3768
April1st to 10thNight
12%5%25%5%5%5%46%7%45%
1900
11th to 20thNight
15%7%25%33335%7%47%
1875
21st to endNight
13%6%36%5%4436%8%43%
1802
May1st to 10thNight
12%8%37%5%4446%9%38%
2813
11th to 20thNight
14%9%37%5%4436%7%39%
2812
21st to endNight
7%5%27%6%46%5%7%11%41%
3079
June1st to 10thNight
7%6%37%5%45%5%6%9%45%
1710
11th to 20thNight
4325%44447%12%52%
1710
21st to endNight
5%4246%46%5%8%12%45%
1556
July1st to 10thNight
6%5%27%5%5%5%6%9%10%37%
2671
11th to 20thNight
8%6%25%5%5%5%48%10%45%
2840
21st to endNight
10%10%410%7%6%7%5%7%9%24%
3087
August1st to 10thNight
35%25%5%4436%9%53%
2878
11th to 20thNight
5%426%445%5%8%12%45%
3100
21st to endNight
5%215%44447%9%56%
3476
September1st to 10thNight
10%6%26%44446%7%46%
1959
11th to 20thNight
10%6%28%5%35%35%7%44%
2090
21st to endNight
11%5%25%34335%8%51%
2090
October1st to 10thNight
10%414333346%59%
2090
11th to 20thNight
15%5%26%433345%51%
2130
21st to endNight
14%8%25%33335%5%49%
2591
November1st to 10thNight
11%7%25%434346%53%
2406
11th to 20thNight
13%8%25%43435%7%48%
2470
21st to endNight
15%9%45%33435%6%43%
2470
December1st to 10thNight
19%11%48%5%4435%5%32%
2470
11th to 20thNight
17%11%37%433345%40%
3042
21st to endNight
15%12%410%6%6%5%45%7%27%
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
58%46%18%13%2
2837
11th to 20thDay
58%37%15%16%1
2840
21st to endDay
57%37%21%11%1
3316
February1st to 10thDay
54%46%17%16%2
1900
11th to 20thDay
55%46%17%14%3
1858
21st to endDay
53%38%15%16%5%
1570
March1st to 10thDay
54%5%6%16%13%7%
3120
11th to 20thDay
40%48%24%17%6%
3411
21st to endDay
44%5%10%26%14%1
3891
April1st to 10thDay
40%5%10%23%18%4
2280
11th to 20thDay
41%46%21%24%4
2254
21st to endDay
42%5%9%27%15%2
2375
May1st to 10thDay
45%8%11%23%12%1
4120
11th to 20thDay
49%6%10%24%11%
4085
21st to endDay
41%7%9%21%19%1
4489
June1st to 10thDay
40%7%13%24%15%2
2470
11th to 20thDay
33%8%17%23%18%2
2470
21st to endDay
35%9%17%20%15%4
2606
July1st to 10thDay
36%10%20%23%8%2
4215
11th to 20thDay
39%9%17%25%8%2
4051
21st to endDay
59%8%11%15%6%1
4324
August1st to 10thDay
28%9%16%31%14%1
4034
11th to 20thDay
34%9%16%26%15%1
3765
21st to endDay
29%9%11%31%18%2
4179
September1st to 10thDay
41%8%11%19%17%5%
2200
11th to 20thDay
41%6%11%21%18%2
2090
21st to endDay
37%6%9%23%20%5%
2090
October1st to 10thDay
32%5%8%22%27%7%
2090
11th to 20thDay
32%38%22%26%9%
2048
21st to endDay
39%37%21%25%6%
1867
November1st to 10thDay
32%39%22%30%5%
1672
11th to 20thDay
38%36%23%24%6%
1710
21st to endDay
43%36%22%21%4
1710
December1st to 10thDay
54%35%21%14%3
1710
11th to 20thDay
51%5%7%19%16%2
2150
21st to endDay
54%5%9%20%10%2
3124
January1st to 10thNight
51%38%21%16%2
4109
11th to 20thNight
55%37%14%17%5%
4120
21st to endNight
56%37%18%15%1
4336
February1st to 10thNight
53%48%18%17%1
2280
11th to 20thNight
55%36%17%14%4
2219
21st to endNight
55%47%15%15%5%
1884
March1st to 10thNight
56%5%8%12%16%5%
3733
11th to 20thNight
37%5%7%25%15%11%
3548
21st to endNight
46%5%8%23%17%1
3768
April1st to 10thNight
37%410%24%21%3
1900
11th to 20thNight
37%47%21%23%7%
1875
21st to endNight
39%5%10%29%17%1
1802
May1st to 10thNight
41%8%13%25%13%1
2840
11th to 20thNight
42%8%13%21%15%1
2813
21st to endNight
34%10%13%24%18%2
3087
June1st to 10thNight
36%7%13%28%15%2
1710
11th to 20thNight
24%7%20%30%17%3
1710
21st to endNight
29%10%16%27%14%5%
1556
July1st to 10thNight
35%11%21%23%9%2
2627
11th to 20thNight
32%8%18%30%8%3
2786
21st to endNight
54%10%12%15%7%1
2988
August1st to 10thNight
25%7%12%37%17%1
2867
11th to 20thNight
28%8%23%27%13%1
3130
21st to endNight
23%8%13%36%19%2
3476
September1st to 10thNight
36%7%13%22%18%5%
1959
11th to 20thNight
38%7%11%19%24%2
2090
21st to endNight
33%5%10%23%25%5%
2090
October1st to 10thNight
28%47%23%28%9%
2090
11th to 20thNight
36%47%22%24%8%
2130
21st to endNight
37%35%22%26%7%
2591
November1st to 10thNight
34%36%23%26%8%
2406
11th to 20thNight
36%27%21%26%7%
2470
21st to endNight
42%36%25%20%4
2470
December1st to 10thNight
54%48%18%14%2
2470
11th to 20thNight
46%36%21%21%3
3044
21st to endNight
56%48%18%13%1
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%17%35%17%6%1
270
11th to 20thDay
31%19%31%11%7%1
270
21st to endDay
22%16%42%16%4
297
February1st to 10thDay
30%16%32%16%7%
270
11th to 20thDay
35%13%37%10%41
270
21st to endDay
32%20%35%12%1
225
March1st to 10thDay
25%16%33%17%7%1
270
11th to 20thDay
24%14%34%20%8%1
417
21st to endDay
24%16%30%19%11%1
506
April1st to 10thDay
18%17%27%25%10%3
460
11th to 20thDay
17%13%25%28%15%2
452
21st to endDay
17%9%32%25%14%3
460
May1st to 10thDay
17%10%27%25%16%5%
463
11th to 20thDay
15%7%21%24%21%11%
487
21st to endDay
12%417%27%22%18%
529
June1st to 10thDay
11%6%17%23%25%18%
490
11th to 20thDay
6%313%27%31%22%
490
21st to endDay
8%215%29%27%19%
626
July1st to 10thDay
10%38%27%28%24%
580
11th to 20thDay
12%37%21%30%27%
484
21st to endDay
11%310%18%30%28%
532
August1st to 10thDay
10%310%21%31%25%
486
11th to 20thDay
11%114%24%37%14%
479
21st to endDay
11%17%21%32%28%
539
September1st to 10thDay
13%110%20%34%21%
490
11th to 20thDay
14%311%19%32%21%
490
21st to endDay
17%413%25%28%13%
490
October1st to 10thDay
13%218%28%28%12%
490
11th to 20thDay
12%8%28%28%19%5%
490
21st to endDay
18%10%21%29%17%4
354
November1st to 10thDay
17%5%27%30%16%5%
270
11th to 20thDay
13%12%34%31%9%
270
21st to endDay
19%11%35%20%13%3
270
December1st to 10thDay
25%15%31%20%7%1
270
11th to 20thDay
22%13%30%21%13%1
270
21st to endDay
24%19%31%20%6%1
297
January1st to 10thNight
23%13%33%26%5%
760
11th to 20thNight
26%16%32%21%5%
760
21st to endNight
20%12%41%24%3
836
February1st to 10thNight
25%12%32%26%4
760
11th to 20thNight
29%14%34%22%2
743
21st to endNight
31%13%34%20%1
628
March1st to 10thNight
22%12%31%31%4
760
11th to 20thNight
23%10%35%24%7%1
760
21st to endNight
20%10%32%29%9%
812
April1st to 10thNight
14%10%33%33%10%
570
11th to 20thNight
18%7%31%32%12%1
563
21st to endNight
16%6%28%35%13%1
570
May1st to 10thNight
13%5%29%31%20%1
570
11th to 20thNight
14%320%36%22%5%
561
21st to endNight
8%213%37%32%7%
617
June1st to 10thNight
9%215%34%35%5%
570
11th to 20thNight
5%112%35%39%8%
570
21st to endNight
6%29%39%38%7%
570
July1st to 10thNight
11%18%28%40%13%
555
11th to 20thNight
7%17%28%43%12%
552
21st to endNight
9%27%30%42%10%
624
August1st to 10thNight
8%2428%48%10%
567
11th to 20thNight
8%19%32%44%7%
564
21st to endNight
9%26%26%48%10%
627
September1st to 10thNight
12%38%31%39%8%
629
11th to 20thNight
13%212%30%37%7%
760
21st to endNight
13%216%29%34%5%
760
October1st to 10thNight
12%315%32%31%6%
760
11th to 20thNight
17%5%22%36%18%2
760
21st to endNight
18%5%24%34%17%2
812
November1st to 10thNight
14%6%23%34%21%2
740
11th to 20thNight
17%8%30%33%11%1
760
21st to endNight
21%9%27%32%11%1
760
December1st to 10thNight
27%11%28%28%7%
760
11th to 20thNight
23%8%31%30%8%1
760
21st to endNight
26%14%28%27%6%
836
Page generated at 2024-10-22 19:20:59. Version ac07

Copyright © 2024 Attilla Danko.


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