Hannibal
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Hannibal clear sky chart from 2005-11-06 to 2024-02-10.

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
39%
24619
13%
80182
9%
24513
44%
24513
13%
61012

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
22%
941
9%
4387
4%
926
28%
926
7%
3363
January11th to 20thNight
21%
950
11%
4143
4%
930
26%
930
7%
3300
January21st to endNight
21%
1039
7%
4492
3%
1023
25%
1023
6%
3722
February1st to 10thNight
22%
948
11%
2464
2%
948
27%
948
13%
1992
February11th to 20thNight
25%
793
12%
2189
4%
789
29%
789
12%
1726
February21st to endNight
20%
592
15%
1776
4%
592
29%
592
13%
1371
March1st to 10thNight
22%
658
16%
2098
6%
658
31%
658
14%
1554
March11th to 20thNight
31%
540
12%
1980
8%
540
36%
540
10%
1524
March21st to endNight
21%
594
6%
2102
3%
594
26%
594
7%
1756
April1st to 10thNight
29%
540
14%
1800
7%
540
38%
540
14%
1299
April11th to 20thNight
33%
533
16%
1775
12%
533
42%
533
14%
1317
April21st to endNight
33%
540
15%
1800
9%
540
43%
540
13%
1372
May1st to 10thNight
35%
540
10%
1685
7%
540
41%
540
13%
1292
May11th to 20thNight
42%
531
16%
1417
11%
531
46%
531
15%
1125
May21st to endNight
49%
584
16%
1551
9%
582
54%
582
18%
1186
June1st to 10thNight
63%
540
14%
1440
9%
540
65%
540
23%
1041
June11th to 20thNight
59%
540
19%
1440
11%
540
63%
540
22%
1038
June21st to endNight
59%
540
16%
1440
9%
540
61%
540
22%
1067
July1st to 10thNight
68%
525
13%
1400
10%
525
68%
525
20%
1041
July11th to 20thNight
68%
522
17%
1392
13%
522
70%
522
22%
1014
July21st to endNight
71%
591
16%
1628
16%
558
72%
558
19%
1189
August1st to 10thNight
76%
537
17%
1601
19%
534
77%
534
24%
1096
August11th to 20thNight
70%
534
19%
1704
21%
534
72%
534
19%
1178
August21st to endNight
75%
594
19%
1980
23%
594
77%
594
23%
1302
September1st to 10thNight
64%
540
18%
1800
19%
540
68%
540
19%
1258
September11th to 20thNight
60%
540
24%
1800
22%
540
65%
540
17%
1282
September21st to endNight
56%
684
19%
2020
12%
684
61%
684
21%
1407
October1st to 10thNight
51%
720
20%
2160
15%
720
55%
720
24%
1435
October11th to 20thNight
36%
720
16%
2160
8%
720
43%
720
15%
1610
October21st to endNight
29%
792
14%
2376
6%
792
37%
792
13%
1833
November1st to 10thNight
38%
740
17%
2393
10%
740
47%
740
17%
1676
November11th to 20thNight
29%
760
17%
2470
10%
760
38%
760
13%
1849
November21st to endNight
27%
940
12%
2650
6%
940
33%
940
14%
2069
December1st to 10thNight
26%
950
9%
2660
3%
950
31%
950
11%
2163
December11th to 20thNight
28%
949
13%
3151
4%
948
32%
948
10%
2381
December21st to endNight
19%
1038
5%
4858
2%
1026
24%
1026
5%
4184

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%7%36%5%35%5%5%7%40%
78343
Night
13%8%36%5%3445%6%41%
80678
TransparencyDay
30%34%8%17%10%1
78052
Night
32%32%7%16%10%2
80489
SeeingDay
15%10%27%27%16%5%
14622
Night
16%9%30%30%13%1
24643

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
11%11%5%12%7%445%5%6%29%
2527
11th to 20thDay
12%10%5%8%8%5%8%5%6%5%30%
2757
21st to endDay
18%17%9%8%6%23435%24%
3135
February1st to 10thDay
15%10%5%9%5%36%446%32%
1701
11th to 20thDay
14%10%37%5%46%5%5%7%34%
1658
21st to endDay
15%11%47%6%35%346%36%
1480
March1st to 10thDay
15%10%5%7%5%3445%5%38%
1878
11th to 20thDay
16%9%46%6%345%5%6%37%
1980
21st to endDay
19%11%47%6%35%45%6%29%
2254
April1st to 10thDay
14%8%37%5%3445%7%40%
2160
11th to 20thDay
16%7%37%5%3345%7%40%
2134
21st to endDay
20%6%36%5%3445%7%35%
2160
May1st to 10thDay
14%8%46%6%35%5%5%8%35%
2271
11th to 20thDay
16%7%36%5%35%5%5%7%38%
2479
21st to endDay
12%6%37%6%46%5%7%8%37%
2725
June1st to 10thDay
5%325%5%45%6%7%10%46%
2520
11th to 20thDay
7%5%35%435%6%7%9%46%
2520
21st to endDay
8%5%35%6%36%5%6%10%45%
2520
July1st to 10thDay
7%425%5%35%6%8%10%45%
2520
11th to 20thDay
5%425%5%36%6%7%10%48%
2520
21st to endDay
7%425%5%36%5%7%10%45%
2590
August1st to 10thDay
7%5%25%6%36%6%8%10%41%
2328
11th to 20thDay
8%426%5%46%5%6%9%44%
2194
21st to endDay
8%4244345%7%9%49%
2376
September1st to 10thDay
11%6%2433445%8%50%
2160
11th to 20thDay
10%42443345%7%53%
2160
21st to endDay
7%4245%345%6%8%53%
1918
October1st to 10thDay
11%6%24434446%51%
1800
11th to 20thDay
15%7%35%424446%46%
1800
21st to endDay
18%8%35%433446%43%
1980
November1st to 10thDay
11%6%34324447%52%
1682
11th to 20thDay
16%6%36%42345%7%44%
1710
21st to endDay
17%10%46%434445%39%
1525
December1st to 10thDay
12%10%5%6%6%34446%39%
1520
11th to 20thDay
15%9%46%5%35%45%7%38%
1918
21st to endDay
19%16%5%9%7%35%45%5%22%
2783
January1st to 10thNight
13%11%6%11%6%44445%32%
4428
11th to 20thNight
13%16%6%8%5%37%6%5%426%
4212
21st to endNight
21%17%6%9%5%23346%23%
4532
February1st to 10thNight
15%12%5%7%5%45%446%34%
2464
11th to 20thNight
15%8%46%6%34447%39%
2188
21st to endNight
16%9%37%5%34446%40%
1776
March1st to 10thNight
14%10%36%424445%44%
2098
11th to 20thNight
17%8%37%5%35%447%37%
1980
21st to endNight
21%9%47%7%36%45%6%27%
2102
April1st to 10thNight
12%7%36%5%3445%7%46%
1800
11th to 20thNight
14%7%25%5%345%46%45%
1775
21st to endNight
17%7%37%5%24445%41%
1800
May1st to 10thNight
13%5%36%7%35%47%7%40%
1685
11th to 20thNight
14%7%46%6%345%46%43%
1416
21st to endNight
10%6%36%6%35%5%6%9%42%
1551
June1st to 10thNight
7%4243345%5%9%54%
1440
11th to 20thNight
7%5%25%5%35%46%9%48%
1440
21st to endNight
6%324445%6%5%10%50%
1440
July1st to 10thNight
8%425%5%345%6%9%49%
1440
11th to 20thNight
6%3245%35%36%7%56%
1440
21st to endNight
7%3244346%5%9%54%
1724
August1st to 10thNight
5%324435%6%6%11%50%
1611
11th to 20thNight
7%4245%345%5%7%53%
1704
21st to endNight
6%3143245%6%9%56%
1980
September1st to 10thNight
11%5%233245%47%55%
1800
11th to 20thNight
7%5%26%5%2445%7%53%
1800
21st to endNight
6%3245%44448%56%
2020
October1st to 10thNight
9%42442445%7%55%
2160
11th to 20thNight
14%5%24424435%52%
2160
21st to endNight
18%7%35%43345%5%44%
2376
November1st to 10thNight
10%6%26%323446%55%
2393
11th to 20thNight
12%7%35%5%3345%6%47%
2470
21st to endNight
17%9%35%42435%6%42%
2650
December1st to 10thNight
15%9%47%6%345%6%6%36%
2660
11th to 20thNight
16%8%36%5%34445%42%
3279
21st to endNight
21%17%7%9%7%3433421%
4884

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
45%23%7%19%5%
2528
11th to 20thDay
44%23%12%14%7%
2757
21st to endDay
55%20%7%11%7%
3135
February1st to 10thDay
36%34%7%14%8%1
1701
11th to 20thDay
32%36%8%13%9%1
1667
21st to endDay
34%34%7%18%6%1
1480
March1st to 10thDay
32%35%6%19%8%1
1878
11th to 20thDay
33%36%10%14%6%1
1980
21st to endDay
39%35%8%12%5%1
2254
April1st to 10thDay
27%35%8%20%10%
2160
11th to 20thDay
31%33%5%19%9%2
2134
21st to endDay
32%35%10%15%8%1
2160
May1st to 10thDay
34%36%8%14%7%1
2271
11th to 20thDay
32%35%7%15%10%1
2483
21st to endDay
31%37%7%13%11%1
2725
June1st to 10thDay
23%36%10%21%10%
2520
11th to 20thDay
20%36%8%17%16%3
2520
21st to endDay
24%35%8%16%14%3
2520
July1st to 10thDay
22%36%10%19%9%2
2451
11th to 20thDay
21%36%10%18%12%2
2445
21st to endDay
24%37%7%20%9%2
2446
August1st to 10thDay
24%35%10%19%10%1
2314
11th to 20thDay
24%34%9%20%12%1
2194
21st to endDay
17%35%6%20%16%5%
2376
September1st to 10thDay
24%35%5%17%14%5%
2160
11th to 20thDay
23%34%421%16%1
2160
21st to endDay
20%36%5%21%17%2
1918
October1st to 10thDay
18%34%6%22%17%3
1800
11th to 20thDay
29%34%6%16%13%1
1800
21st to endDay
29%35%6%17%11%2
1980
November1st to 10thDay
20%39%8%18%12%3
1682
11th to 20thDay
26%38%7%16%11%2
1710
21st to endDay
28%39%7%17%9%
1525
December1st to 10thDay
31%38%10%15%6%
1520
11th to 20thDay
35%30%9%19%8%1
1915
21st to endDay
54%24%7%11%4
2783
January1st to 10thNight
47%23%7%18%5%
4428
11th to 20thNight
50%23%7%12%8%
4212
21st to endNight
56%20%6%13%4
4532
February1st to 10thNight
36%33%7%14%8%1
2464
11th to 20thNight
32%36%6%15%10%2
2189
21st to endNight
32%34%7%18%7%2
1776
March1st to 10thNight
28%34%6%20%10%1
2098
11th to 20thNight
34%35%8%15%7%2
1980
21st to endNight
41%35%7%12%41
2102
April1st to 10thNight
26%35%7%18%13%2
1800
11th to 20thNight
29%34%5%17%12%4
1775
21st to endNight
30%35%7%16%11%1
1800
May1st to 10thNight
30%35%8%16%9%1
1685
11th to 20thNight
30%37%5%13%14%1
1417
21st to endNight
25%37%7%16%12%3
1552
June1st to 10thNight
20%35%11%22%10%2
1440
11th to 20thNight
21%35%7%16%18%3
1440
21st to endNight
21%36%9%14%16%4
1440
July1st to 10thNight
22%37%8%20%11%2
1400
11th to 20thNight
20%36%6%20%14%3
1392
21st to endNight
22%37%7%22%11%2
1628
August1st to 10thNight
16%35%11%23%11%3
1601
11th to 20thNight
21%34%6%23%15%1
1704
21st to endNight
16%35%7%19%17%7%
1980
September1st to 10thNight
22%35%5%15%18%6%
1800
11th to 20thNight
23%35%418%17%2
1800
21st to endNight
19%35%5%18%20%3
2020
October1st to 10thNight
15%34%7%20%21%3
2160
11th to 20thNight
27%35%5%17%12%4
2160
21st to endNight
30%35%414%14%2
2376
November1st to 10thNight
18%39%8%19%13%3
2393
11th to 20thNight
26%38%6%17%12%1
2470
21st to endNight
28%38%7%17%9%1
2650
December1st to 10thNight
33%38%8%17%4
2660
11th to 20thNight
34%31%7%18%10%
3281
21st to endNight
58%23%6%9%4
4884

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%19%35%23%6%
270
11th to 20thDay
27%18%40%14%1
270
21st to endDay
17%20%40%20%3
297
February1st to 10thDay
24%18%38%15%4
267
11th to 20thDay
23%21%33%16%6%
240
21st to endDay
25%17%39%16%3
198
March1st to 10thDay
18%22%43%16%1
240
11th to 20thDay
27%14%34%20%41
240
21st to endDay
31%19%32%14%4
340
April1st to 10thDay
20%16%33%22%8%1
420
11th to 20thDay
19%13%31%25%10%1
412
21st to endDay
22%12%35%24%7%1
420
May1st to 10thDay
18%11%37%22%11%2
508
11th to 20thDay
21%11%25%27%12%3
625
21st to endDay
14%8%29%26%16%7%
679
June1st to 10thDay
7%5%21%34%25%9%
630
11th to 20thDay
8%324%36%23%5%
630
21st to endDay
8%7%29%34%18%3
630
July1st to 10thDay
9%315%33%26%14%
621
11th to 20thDay
8%419%38%25%7%
618
21st to endDay
10%118%33%31%7%
684
August1st to 10thDay
8%215%40%26%8%
626
11th to 20thDay
7%216%34%29%10%
508
21st to endDay
9%215%32%32%12%
495
September1st to 10thDay
13%5%16%29%28%9%
450
11th to 20thDay
8%317%33%27%12%
450
21st to endDay
6%8%24%31%21%10%
370
October1st to 10thDay
16%9%29%28%13%6%
270
11th to 20thDay
15%23%32%22%8%
270
21st to endDay
26%16%31%22%41
297
November1st to 10thDay
11%9%41%24%10%4
270
11th to 20thDay
20%17%29%24%8%2
270
21st to endDay
23%16%31%24%6%
270
December1st to 10thDay
13%13%45%19%6%4
270
11th to 20thDay
18%17%37%24%4
270
21st to endDay
25%23%35%14%3
297
January1st to 10thNight
16%16%40%23%6%
950
11th to 20thNight
20%16%37%22%5%
950
21st to endNight
19%13%39%26%2
1045
February1st to 10thNight
21%13%39%25%3
948
11th to 20thNight
19%16%36%25%4
794
21st to endNight
21%18%37%22%2
592
March1st to 10thNight
19%14%41%21%5%
658
11th to 20thNight
22%11%33%29%6%1
540
21st to endNight
25%12%33%24%4
594
April1st to 10thNight
14%16%37%28%5%
540
11th to 20thNight
18%11%35%28%8%
533
21st to endNight
21%7%35%31%6%
540
May1st to 10thNight
15%8%34%34%8%1
540
11th to 20thNight
17%6%28%35%13%1
531
21st to endNight
12%426%33%22%2
584
June1st to 10thNight
8%320%42%26%2
540
11th to 20thNight
11%221%42%23%2
540
21st to endNight
6%227%43%21%1
540
July1st to 10thNight
9%310%38%36%4
525
11th to 20thNight
7%116%44%28%3
522
21st to endNight
8%113%43%34%1
591
August1st to 10thNight
5%210%49%30%4
537
11th to 20thNight
8%111%41%33%5%
534
21st to endNight
7%112%38%41%2
594
September1st to 10thNight
13%217%38%26%4
540
11th to 20thNight
9%321%36%26%5%
540
21st to endNight
8%6%24%35%23%5%
684
October1st to 10thNight
11%5%29%33%21%3
720
11th to 20thNight
18%9%33%29%10%1
720
21st to endNight
22%11%34%26%7%
792
November1st to 10thNight
14%9%36%31%9%1
740
11th to 20thNight
16%14%38%27%5%
760
21st to endNight
23%11%36%24%6%
940
December1st to 10thNight
18%12%38%26%5%1
950
11th to 20thNight
24%9%33%27%6%
950
21st to endNight
24%17%34%23%3
1045
Page generated at 2024-02-07 05:11:53. Version ac07

Copyright 2024 Attilla Danko


Hannibal Clear Sky Chart |Charts Home