Vicksburg
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Vicksburg clear sky chart from 2005-11-06 to 2024-01-11.

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%
23768
23%
74567
17%
23710
56%
23710
30%
44607

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
27%
950
23%
2458
7%
946
38%
946
28%
1606
January11th to 20thNight
31%
905
24%
2353
10%
905
40%
905
26%
1594
January21st to endNight
25%
990
25%
2574
8%
990
36%
990
27%
1734
February1st to 10thNight
26%
742
23%
2182
9%
742
37%
742
24%
1426
February11th to 20thNight
28%
703
21%
2099
9%
700
37%
700
23%
1349
February21st to endNight
20%
592
22%
1776
7%
592
32%
592
18%
1235
March1st to 10thNight
32%
604
24%
2044
14%
604
42%
604
24%
1218
March11th to 20thNight
30%
540
19%
1980
12%
540
39%
540
20%
1262
March21st to endNight
34%
594
23%
2106
15%
594
45%
594
26%
1225
April1st to 10thNight
35%
540
26%
1800
17%
540
48%
540
28%
1048
April11th to 20thNight
37%
533
26%
1775
17%
533
51%
533
28%
1025
April21st to endNight
42%
540
28%
1800
21%
540
56%
540
36%
964
May1st to 10thNight
55%
540
23%
1800
19%
540
64%
540
36%
985
May11th to 20thNight
55%
531
20%
1769
20%
531
60%
531
33%
1015
May21st to endNight
64%
583
20%
1885
20%
582
68%
582
35%
1063
June1st to 10thNight
70%
540
19%
1472
17%
540
72%
540
34%
930
June11th to 20thNight
77%
540
24%
1440
22%
540
79%
540
46%
815
June21st to endNight
72%
540
20%
1614
21%
540
74%
540
34%
949
July1st to 10thNight
74%
525
16%
1575
19%
525
74%
525
33%
956
July11th to 20thNight
78%
522
17%
1566
20%
522
79%
522
32%
956
July21st to endNight
79%
591
19%
1690
22%
558
80%
558
37%
969
August1st to 10thNight
83%
537
16%
1778
20%
534
84%
534
38%
948
August11th to 20thNight
75%
534
18%
1776
22%
534
76%
534
30%
1069
August21st to endNight
73%
594
21%
1980
25%
594
74%
594
29%
1203
September1st to 10thNight
73%
540
25%
1800
29%
540
74%
540
31%
1060
September11th to 20thNight
69%
540
26%
1800
27%
540
71%
540
32%
1035
September21st to endNight
69%
710
32%
1970
26%
710
70%
710
41%
1126
October1st to 10thNight
68%
720
31%
2155
24%
720
72%
720
46%
1116
October11th to 20thNight
54%
720
33%
2160
24%
720
63%
720
37%
1237
October21st to endNight
51%
792
31%
2376
24%
792
57%
792
35%
1358
November1st to 10thNight
55%
740
32%
2220
24%
740
64%
740
39%
1219
November11th to 20thNight
45%
760
29%
2384
23%
760
54%
760
35%
1321
November21st to endNight
42%
760
27%
2470
19%
760
52%
760
28%
1457
December1st to 10thNight
37%
760
25%
2470
16%
760
48%
760
24%
1545
December11th to 20thNight
33%
876
22%
3068
13%
876
42%
876
21%
1923
December21st to endNight
27%
1040
14%
4402
9%
1026
34%
1026
16%
2666

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
11%6%35%5%35%5%6%8%43%
74563
Night
11%6%2443445%8%48%
75102
TransparencyDay
38%7%11%19%18%6%
74290
Night
34%6%12%19%20%8%
74896
SeeingDay
14%8%21%25%22%9%
13923
Night
14%8%24%30%20%4
23776

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
18%7%35%323447%45%
1707
11th to 20thDay
19%8%35%43345%5%42%
1620
21st to endDay
18%7%35%423345%45%
1782
February1st to 10thDay
18%7%35%5%245%46%41%
1774
11th to 20thDay
20%8%36%433446%40%
1748
21st to endDay
19%9%46%5%3344438%
1480
March1st to 10thDay
16%7%36%5%3445%6%42%
1930
11th to 20thDay
15%7%35%5%45%5%5%7%38%
1980
21st to endDay
10%6%37%6%45%5%6%7%42%
2247
April1st to 10thDay
11%6%35%5%35%5%5%7%46%
2160
11th to 20thDay
14%6%36%5%35%45%7%42%
2134
21st to endDay
9%5%35%4445%6%7%47%
2160
May1st to 10thDay
10%5%36%6%46%6%5%8%42%
2160
11th to 20thDay
9%5%26%6%36%5%7%9%43%
2124
21st to endDay
6%436%7%46%7%7%9%40%
2383
June1st to 10thDay
9%436%7%5%7%6%8%10%36%
2475
11th to 20thDay
4437%6%5%6%7%7%10%42%
2512
21st to endDay
6%435%6%47%7%7%10%40%
2340
July1st to 10thDay
6%5%37%7%5%7%8%9%11%32%
2340
11th to 20thDay
8%435%7%5%8%9%8%11%31%
2340
21st to endDay
7%5%26%7%48%8%9%11%33%
2524
August1st to 10thDay
5%425%7%5%7%7%9%12%38%
2148
11th to 20thDay
7%6%36%7%5%7%6%7%10%36%
2125
21st to endDay
12%5%24446%7%6%11%39%
2376
September1st to 10thDay
8%5%25%5%46%6%7%8%42%
2160
11th to 20thDay
10%5%26%6%35%5%47%46%
2149
21st to endDay
10%5%14424447%54%
1980
October1st to 10thDay
6%424435%447%58%
1800
11th to 20thDay
9%5%2442445%7%54%
1800
21st to endDay
14%5%24333335%55%
1980
November1st to 10thDay
10%424433445%57%
1858
11th to 20thDay
11%7%25%334436%52%
1791
21st to endDay
16%6%3443445%6%46%
1710
December1st to 10thDay
17%8%26%5%33447%40%
1710
11th to 20thDay
15%10%36%5%3445%6%41%
1985
21st to endDay
16%7%35%4245%5%6%44%
3071
January1st to 10thNight
17%7%34423436%47%
2458
11th to 20thNight
19%7%35%5%24445%43%
2353
21st to endNight
17%8%35%433445%43%
2574
February1st to 10thNight
16%8%36%42345%6%42%
2182
11th to 20thNight
19%8%34433436%45%
2098
21st to endNight
22%8%35%6%24435%38%
1776
March1st to 10thNight
14%7%25%43445%7%46%
2044
11th to 20thNight
14%6%35%6%36%5%5%7%40%
1980
21st to endNight
13%6%25%43435%7%48%
2106
April1st to 10thNight
10%6%344345%5%9%48%
1800
11th to 20thNight
13%5%3442346%7%48%
1775
21st to endNight
7%5%25%5%25%45%8%54%
1800
May1st to 10thNight
7%4243345%6%10%52%
1800
11th to 20thNight
8%5%245%35%5%7%10%46%
1769
21st to endNight
5%425%6%35%5%7%12%48%
1885
June1st to 10thNight
6%5%35%5%36%5%6%9%47%
1472
11th to 20thNight
33233345%8%11%54%
1440
21st to endNight
43247%346%7%11%49%
1614
July1st to 10thNight
5%4246%4448%12%46%
1620
11th to 20thNight
6%3145%36%6%8%9%49%
1620
21st to endNight
43245%35%6%7%14%48%
1790
August1st to 10thNight
2213435%6%8%14%49%
1790
11th to 20thNight
6%425%436%6%8%13%43%
1776
21st to endNight
10%4245%26%5%7%10%46%
1980
September1st to 10thNight
7%5%25%435%6%7%9%49%
1800
11th to 20thNight
7%5%34445%5%6%8%49%
1800
21st to endNight
9%42442345%8%55%
1970
October1st to 10thNight
6%313324446%63%
2155
11th to 20thNight
12%424433446%54%
2160
21st to endNight
14%5%24423235%56%
2376
November1st to 10thNight
11%424324336%58%
2220
11th to 20thNight
12%6%23323446%56%
2384
21st to endNight
13%6%25%42445%6%48%
2470
December1st to 10thNight
17%6%345%3445%6%45%
2470
11th to 20thNight
14%8%35%5%44445%45%
3207
21st to endNight
16%9%36%42335%6%43%
4588

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
40%5%6%20%23%6%
1708
11th to 20thDay
45%46%16%22%7%
1620
21st to endDay
42%35%18%25%7%
1782
February1st to 10thDay
44%48%17%17%9%
1774
11th to 20thDay
47%45%17%18%7%
1758
21st to endDay
49%5%6%13%17%9%
1480
March1st to 10thDay
43%5%10%14%20%9%
1930
11th to 20thDay
44%7%10%15%17%6%
1980
21st to endDay
40%7%9%19%22%4
2247
April1st to 10thDay
38%6%9%23%18%7%
2160
11th to 20thDay
41%5%8%17%23%6%
2134
21st to endDay
35%6%9%24%23%2
2160
May1st to 10thDay
38%8%11%18%19%5%
2160
11th to 20thDay
36%9%14%25%15%1
2128
21st to endDay
37%9%15%24%15%1
2383
June1st to 10thDay
39%9%15%23%12%1
2475
11th to 20thDay
35%10%16%22%14%3
2512
21st to endDay
36%10%16%21%14%2
2340
July1st to 10thDay
40%13%19%19%7%2
2276
11th to 20thDay
39%14%22%17%7%1
2271
21st to endDay
39%13%19%19%9%1
2384
August1st to 10thDay
34%13%21%25%8%
2136
11th to 20thDay
39%13%16%19%10%3
2125
21st to endDay
37%10%19%18%12%3
2376
September1st to 10thDay
35%10%15%17%16%6%
2160
11th to 20thDay
39%7%10%17%20%8%
2149
21st to endDay
29%6%11%24%19%11%
1980
October1st to 10thDay
27%6%9%21%24%13%
1800
11th to 20thDay
30%5%7%16%30%13%
1800
21st to endDay
33%35%17%31%12%
1980
November1st to 10thDay
30%5%7%17%31%10%
1858
11th to 20thDay
34%46%16%27%13%
1791
21st to endDay
39%47%20%22%9%
1710
December1st to 10thDay
43%5%10%17%16%9%
1710
11th to 20thDay
45%5%6%14%24%6%
1982
21st to endDay
39%5%8%18%28%2
3071
January1st to 10thNight
40%37%17%25%7%
2458
11th to 20thNight
43%47%18%19%8%
2353
21st to endNight
43%36%15%25%8%
2574
February1st to 10thNight
43%5%7%18%20%8%
2182
11th to 20thNight
42%46%17%21%10%
2099
21st to endNight
49%5%5%13%17%11%
1776
March1st to 10thNight
38%5%9%16%23%10%
2044
11th to 20thNight
43%7%10%16%17%8%
1980
21st to endNight
36%6%10%19%23%6%
2106
April1st to 10thNight
34%6%11%20%19%9%
1800
11th to 20thNight
35%5%10%19%22%10%
1775
21st to endNight
28%5%11%24%27%5%
1800
May1st to 10thNight
27%8%12%24%22%7%
1800
11th to 20thNight
31%8%17%25%18%2
1770
21st to endNight
27%9%17%28%18%1
1886
June1st to 10thNight
32%9%16%25%16%2
1472
11th to 20thNight
22%8%19%29%17%4
1440
21st to endNight
28%10%18%25%16%3
1614
July1st to 10thNight
29%12%23%25%8%4
1575
11th to 20thNight
27%14%24%24%9%2
1566
21st to endNight
25%11%25%27%11%1
1690
August1st to 10thNight
20%13%29%26%11%
1778
11th to 20thNight
30%12%22%19%14%3
1776
21st to endNight
32%11%18%19%15%5%
1980
September1st to 10thNight
31%10%14%22%17%7%
1800
11th to 20thNight
30%9%15%16%20%10%
1800
21st to endNight
28%6%10%23%21%12%
1970
October1st to 10thNight
22%5%10%21%25%16%
2155
11th to 20thNight
31%46%15%28%15%
2160
21st to endNight
32%46%15%27%15%
2376
November1st to 10thNight
29%37%18%28%15%
2220
11th to 20thNight
30%48%16%27%15%
2384
21st to endNight
37%47%20%20%12%
2470
December1st to 10thNight
40%6%10%17%20%7%
2470
11th to 20thNight
41%47%13%26%8%
3209
21st to endNight
43%5%6%17%24%5%
4588

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
21%23%39%14%21
270
11th to 20thDay
28%17%34%13%9%
240
21st to endDay
28%22%33%14%2
264
February1st to 10thDay
27%17%38%13%41
240
11th to 20thDay
40%13%34%11%2
240
21st to endDay
30%24%36%9%1
198
March1st to 10thDay
26%17%38%18%2
240
11th to 20thDay
25%22%36%14%3
240
21st to endDay
20%19%35%20%6%
333
April1st to 10thDay
16%16%34%23%10%
420
11th to 20thDay
23%14%28%24%10%2
412
21st to endDay
16%9%31%30%14%1
420
May1st to 10thDay
14%10%30%31%14%2
423
11th to 20thDay
13%5%26%29%21%7%
447
21st to endDay
9%421%31%25%10%
531
June1st to 10thDay
10%414%33%27%11%
630
11th to 20thDay
4416%36%30%9%
630
21st to endDay
8%211%32%32%15%
630
July1st to 10thDay
429%33%37%14%
621
11th to 20thDay
6%25%24%41%22%
618
21st to endDay
6%28%27%40%17%
662
August1st to 10thDay
6%19%22%39%23%
446
11th to 20thDay
9%15%25%41%19%
439
21st to endDay
14%36%20%35%24%
495
September1st to 10thDay
6%310%28%37%16%
450
11th to 20thDay
10%410%24%35%16%
450
21st to endDay
11%410%31%32%11%
450
October1st to 10thDay
8%6%22%36%20%9%
270
11th to 20thDay
9%9%29%30%19%5%
270
21st to endDay
23%11%24%27%12%4
297
November1st to 10thDay
16%7%30%32%12%4
270
11th to 20thDay
16%13%37%22%11%
270
21st to endDay
17%15%38%17%11%2
270
December1st to 10thDay
23%16%34%21%5%1
270
11th to 20thDay
22%13%36%24%5%1
270
21st to endDay
25%16%36%16%5%1
297
January1st to 10thNight
23%14%33%25%5%
950
11th to 20thNight
23%15%28%26%8%
905
21st to endNight
21%14%36%25%3
990
February1st to 10thNight
21%13%36%25%5%
742
11th to 20thNight
27%15%29%25%5%
703
21st to endNight
27%18%33%22%1
592
March1st to 10thNight
19%16%31%28%6%
604
11th to 20thNight
18%11%38%26%7%1
540
21st to endNight
17%8%39%28%8%
594
April1st to 10thNight
16%10%37%27%10%
540
11th to 20thNight
15%12%33%30%10%1
533
21st to endNight
9%10%36%32%13%
540
May1st to 10thNight
9%5%27%45%12%1
540
11th to 20thNight
10%326%36%23%2
531
21st to endNight
6%119%38%29%6%
584
June1st to 10thNight
8%212%39%35%4
540
11th to 20thNight
3112%34%43%6%
540
21st to endNight
4112%30%41%11%
540
July1st to 10thNight
418%30%47%10%
525
11th to 20thNight
415%29%46%15%
522
21st to endNight
5%1434%43%13%
591
August1st to 10thNight
215%28%47%17%
537
11th to 20thNight
7%16%28%47%11%
534
21st to endNight
10%16%24%44%13%
594
September1st to 10thNight
8%28%31%43%8%
540
11th to 20thNight
9%212%27%42%8%
540
21st to endNight
11%211%35%36%5%
710
October1st to 10thNight
7%317%37%31%5%
720
11th to 20thNight
14%6%22%35%22%2
720
21st to endNight
17%7%22%31%20%3
792
November1st to 10thNight
13%6%22%38%20%2
740
11th to 20thNight
15%9%27%34%13%1
760
21st to endNight
17%9%29%30%14%1
760
December1st to 10thNight
21%10%28%32%8%
760
11th to 20thNight
20%12%31%29%8%
878
21st to endNight
25%13%30%25%6%
1045
Page generated at 2024-01-08 10:14:21. Version ac07

Copyright 2024 Attilla Danko


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