La Vergne
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the La Vergne clear sky chart from 2005-11-06 to 2024-01-10.

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
46%
23684
21%
74142
16%
23627
53%
23627
26%
47010

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
18%
2647
9%
946
35%
946
22%
1817
January11th to 20thNight
22%
753
16%
2373
9%
753
30%
753
14%
1737
January21st to endNight
26%
792
23%
2412
10%
792
38%
792
22%
1606
February1st to 10thNight
24%
720
16%
2160
9%
720
31%
720
18%
1559
February11th to 20thNight
21%
703
17%
2099
8%
700
29%
700
18%
1494
February21st to endNight
21%
592
18%
1776
9%
592
28%
592
17%
1282
March1st to 10thNight
30%
720
18%
2160
10%
720
37%
720
22%
1434
March11th to 20thNight
30%
720
17%
2059
10%
720
36%
720
21%
1448
March21st to endNight
35%
702
19%
2088
12%
702
42%
702
23%
1386
April1st to 10thNight
40%
540
26%
1800
16%
540
52%
540
30%
1041
April11th to 20thNight
40%
533
27%
1775
19%
533
53%
533
30%
1046
April21st to endNight
43%
540
23%
1756
16%
540
51%
540
26%
1062
May1st to 10thNight
47%
540
22%
1620
14%
540
54%
540
31%
1008
May11th to 20thNight
52%
531
17%
1593
13%
531
55%
531
27%
1022
May21st to endNight
66%
582
17%
1744
13%
582
69%
582
30%
1093
June1st to 10thNight
64%
540
19%
1620
15%
540
67%
540
31%
994
June11th to 20thNight
76%
540
23%
1472
19%
540
78%
540
45%
822
June21st to endNight
75%
540
21%
1440
17%
540
76%
540
38%
886
July1st to 10thNight
70%
525
16%
1400
14%
525
70%
525
32%
918
July11th to 20thNight
73%
522
19%
1477
18%
522
74%
522
35%
896
July21st to endNight
72%
591
19%
1672
18%
558
72%
558
30%
1057
August1st to 10thNight
75%
537
20%
1693
21%
534
76%
534
31%
1012
August11th to 20thNight
71%
534
17%
1776
19%
534
72%
534
30%
1067
August21st to endNight
73%
594
21%
1980
26%
594
73%
594
29%
1183
September1st to 10thNight
66%
558
24%
1818
26%
558
68%
558
31%
1075
September11th to 20thNight
63%
720
25%
1980
20%
720
66%
720
32%
1253
September21st to endNight
62%
720
30%
1980
22%
720
67%
720
39%
1158
October1st to 10thNight
62%
720
33%
1980
26%
720
66%
720
42%
1111
October11th to 20thNight
47%
720
29%
1998
20%
720
54%
720
32%
1240
October21st to endNight
45%
792
28%
2568
24%
792
54%
792
29%
1531
November1st to 10thNight
53%
740
28%
2406
27%
740
59%
740
32%
1352
November11th to 20thNight
41%
760
29%
2470
21%
760
54%
760
32%
1405
November21st to endNight
39%
760
24%
2470
19%
760
48%
760
26%
1526
December1st to 10thNight
29%
760
18%
2470
11%
760
38%
760
18%
1700
December11th to 20thNight
34%
759
24%
2945
15%
758
45%
758
21%
1775
December21st to endNight
26%
834
12%
4465
10%
821
36%
821
10%
3014

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%6%36%6%35%5%6%8%40%
75132
Night
13%6%35%5%3445%7%43%
74506
TransparencyDay
42%7%11%21%17%3
74846
Night
40%6%10%22%18%4
74313
SeeingDay
16%9%21%24%20%11%
13959
Night
17%8%23%30%20%3
23693

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
17%8%47%5%345%5%6%35%
1509
11th to 20thDay
21%10%5%8%7%24446%30%
1577
21st to endDay
16%8%36%5%34445%42%
1941
February1st to 10thDay
19%10%47%6%34445%34%
1800
11th to 20thDay
20%10%46%5%44445%32%
1748
21st to endDay
22%9%46%433436%36%
1480
March1st to 10thDay
14%9%47%6%34447%39%
1800
11th to 20thDay
20%8%47%6%3445%6%34%
1899
21st to endDay
16%8%37%6%45%5%5%7%34%
2281
April1st to 10thDay
12%5%35%425%5%5%7%47%
2160
11th to 20thDay
13%6%36%5%25%446%45%
2134
21st to endDay
12%6%36%6%45%5%5%7%41%
2204
May1st to 10thDay
16%5%24435%5%6%8%42%
2340
11th to 20thDay
14%6%36%5%45%45%8%39%
2301
21st to endDay
8%6%36%6%35%6%7%9%40%
2531
June1st to 10thDay
9%5%26%6%346%7%9%43%
2340
11th to 20thDay
5%3245%46%6%8%10%46%
2482
21st to endDay
5%3247%46%7%8%11%41%
2520
July1st to 10thDay
8%5%36%8%5%8%6%8%9%34%
2520
11th to 20thDay
8%436%7%46%7%7%11%37%
2430
21st to endDay
8%435%6%46%8%9%11%36%
2547
August1st to 10thDay
6%426%7%47%8%9%11%36%
2230
11th to 20thDay
8%5%37%8%46%7%7%10%36%
2125
21st to endDay
10%425%7%46%6%7%9%39%
2376
September1st to 10thDay
12%5%26%5%35%5%7%9%41%
2124
11th to 20thDay
12%6%246%36%45%7%44%
1980
21st to endDay
11%4245%3445%7%51%
1980
October1st to 10thDay
11%5%2432435%7%54%
1980
11th to 20thDay
12%5%25%434337%52%
1958
21st to endDay
16%7%25%425%445%46%
1787
November1st to 10thDay
12%424313347%57%
1672
11th to 20thDay
15%5%35%42447%6%47%
1710
21st to endDay
15%7%35%5%34446%45%
1710
December1st to 10thDay
22%9%36%5%2445%5%35%
1710
11th to 20thDay
15%9%36%6%445%47%37%
2153
21st to endDay
17%11%48%7%35%5%5%7%29%
3093
January1st to 10thNight
18%8%48%43445%5%38%
2647
11th to 20thNight
20%12%47%7%35%45%5%30%
2373
21st to endNight
16%9%36%5%2445%5%40%
2412
February1st to 10thNight
21%9%47%6%3445%6%32%
2160
11th to 20thNight
22%9%37%5%33445%36%
2098
21st to endNight
24%8%36%5%3445%5%32%
1776
March1st to 10thNight
16%7%25%5%45%5%5%6%40%
2160
11th to 20thNight
18%8%36%445%446%37%
2059
21st to endNight
15%7%36%5%3445%8%39%
2088
April1st to 10thNight
11%4245%25%5%6%7%48%
1800
11th to 20thNight
16%43442345%7%49%
1775
21st to endNight
13%6%34425%46%7%44%
1756
May1st to 10thNight
11%5%26%5%345%6%6%48%
1620
11th to 20thNight
10%5%35%5%345%7%10%44%
1592
21st to endNight
6%436%7%36%6%6%10%43%
1744
June1st to 10thNight
7%426%6%35%5%6%9%47%
1620
11th to 20thNight
43144246%7%12%53%
1472
21st to endNight
34245%46%6%6%13%48%
1440
July1st to 10thNight
9%5%35%5%45%6%7%11%41%
1440
11th to 20thNight
6%435%5%35%5%6%13%45%
1525
21st to endNight
6%426%6%46%7%6%12%41%
1771
August1st to 10thNight
6%425%5%35%5%7%11%46%
1704
11th to 20thNight
7%425%6%35%6%7%9%46%
1776
21st to endNight
8%4246%45%6%6%9%47%
1980
September1st to 10thNight
11%5%25%5%345%5%7%48%
1818
11th to 20thNight
10%5%345%4445%7%48%
1980
21st to endNight
10%425%4336%47%53%
1980
October1st to 10thNight
10%323322446%60%
1980
11th to 20thNight
15%5%25%424446%48%
1998
21st to endNight
16%6%2442335%6%48%
2568
November1st to 10thNight
11%4345%24346%54%
2406
11th to 20thNight
13%6%2442335%8%49%
2470
21st to endNight
17%6%35%433346%46%
2470
December1st to 10thNight
21%10%36%5%3445%6%35%
2470
11th to 20thNight
15%8%46%434445%44%
3042
21st to endNight
17%11%47%7%45%5%5%6%29%
4536

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
50%39%20%15%3
1510
11th to 20thDay
56%38%19%13%1
1577
21st to endDay
45%410%22%17%1
1941
February1st to 10thDay
54%48%19%14%2
1800
11th to 20thDay
55%47%18%13%3
1758
21st to endDay
51%49%15%15%6%
1480
March1st to 10thDay
46%48%18%18%6%
1800
11th to 20thDay
52%410%17%14%2
1899
21st to endDay
50%6%11%19%13%1
2281
April1st to 10thDay
37%5%10%24%20%4
2160
11th to 20thDay
39%5%7%21%22%5%
2134
21st to endDay
43%5%8%25%16%2
2204
May1st to 10thDay
39%7%11%25%15%2
2340
11th to 20thDay
43%8%12%22%14%1
2305
21st to endDay
39%8%13%24%14%2
2531
June1st to 10thDay
38%7%12%24%18%2
2340
11th to 20thDay
30%9%16%24%18%3
2482
21st to endDay
33%10%16%20%16%4
2520
July1st to 10thDay
42%12%14%17%12%3
2451
11th to 20thDay
39%11%17%19%11%4
2356
21st to endDay
35%13%17%23%11%1
2405
August1st to 10thDay
38%12%16%21%11%1
2217
11th to 20thDay
41%10%12%20%15%2
2125
21st to endDay
40%9%13%22%13%3
2376
September1st to 10thDay
39%8%12%20%17%4
2124
11th to 20thDay
39%7%11%22%18%3
1980
21st to endDay
34%5%10%23%22%6%
1980
October1st to 10thDay
31%5%8%23%27%6%
1980
11th to 20thDay
34%38%21%26%8%
1958
21st to endDay
41%47%19%24%5%
1787
November1st to 10thDay
30%48%24%29%6%
1672
11th to 20thDay
36%47%23%24%5%
1710
21st to endDay
41%37%25%20%4
1710
December1st to 10thDay
51%5%6%21%15%2
1710
11th to 20thDay
48%5%10%19%16%2
2150
21st to endDay
53%413%19%9%2
3093
January1st to 10thNight
48%410%21%16%2
2647
11th to 20thNight
57%5%8%17%12%2
2373
21st to endNight
46%39%22%17%3
2412
February1st to 10thNight
53%49%17%15%1
2160
11th to 20thNight
53%46%19%15%4
2099
21st to endNight
54%48%14%15%5%
1776
March1st to 10thNight
44%6%9%14%20%7%
2160
11th to 20thNight
48%6%8%20%16%2
2059
21st to endNight
44%6%11%24%14%2
2088
April1st to 10thNight
34%5%11%24%22%3
1800
11th to 20thNight
36%48%20%23%9%
1775
21st to endNight
37%6%9%26%19%2
1756
May1st to 10thNight
36%6%10%26%19%2
1620
11th to 20thNight
37%10%16%21%16%1
1593
21st to endNight
34%10%14%24%16%2
1745
June1st to 10thNight
35%7%12%26%17%3
1620
11th to 20thNight
23%8%18%32%17%3
1472
21st to endNight
28%10%16%28%13%5%
1440
July1st to 10thNight
34%10%18%21%14%3
1400
11th to 20thNight
31%8%17%25%13%5%
1477
21st to endNight
32%12%16%25%14%2
1672
August1st to 10thNight
32%8%16%28%15%1
1693
11th to 20thNight
32%10%17%23%15%2
1776
21st to endNight
33%9%14%25%15%4
1980
September1st to 10thNight
35%6%12%24%18%4
1818
11th to 20thNight
37%6%11%18%26%2
1980
21st to endNight
30%6%10%23%24%7%
1980
October1st to 10thNight
27%5%9%22%28%9%
1980
11th to 20thNight
37%48%20%23%8%
1998
21st to endNight
38%36%22%26%6%
2568
November1st to 10thNight
34%37%22%27%7%
2406
11th to 20thNight
34%38%21%28%7%
2470
21st to endNight
41%48%22%21%5%
2470
December1st to 10thNight
51%5%9%18%16%2
2470
11th to 20thNight
42%38%21%22%3
3044
21st to endNight
55%410%17%12%2
4536

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
23%17%38%13%6%1
267
11th to 20thDay
31%20%27%14%6%2
240
21st to endDay
21%16%43%17%4
264
February1st to 10thDay
27%14%38%17%4
240
11th to 20thDay
37%18%31%10%5%
240
21st to endDay
34%17%33%13%4
198
March1st to 10thDay
21%15%41%18%5%
240
11th to 20thDay
22%19%31%19%8%1
339
21st to endDay
25%13%32%19%10%1
462
April1st to 10thDay
18%16%25%27%11%2
420
11th to 20thDay
18%12%27%28%13%2
412
21st to endDay
20%12%27%24%13%4
420
May1st to 10thDay
18%10%25%27%15%5%
423
11th to 20thDay
16%6%22%26%19%11%
447
21st to endDay
10%416%25%26%18%
485
June1st to 10thDay
10%5%16%22%26%22%
450
11th to 20thDay
6%413%27%33%18%
592
21st to endDay
6%416%34%23%17%
630
July1st to 10thDay
8%410%26%30%23%
621
11th to 20thDay
9%49%24%32%23%
529
21st to endDay
8%39%23%31%26%
488
August1st to 10thDay
10%29%26%33%20%
446
11th to 20thDay
12%38%30%33%14%
439
21st to endDay
12%37%18%37%22%
495
September1st to 10thDay
12%49%23%34%18%
450
11th to 20thDay
14%38%20%34%21%
450
21st to endDay
15%5%13%28%26%12%
450
October1st to 10thDay
13%5%17%27%28%11%
450
11th to 20thDay
13%11%27%30%15%4
428
21st to endDay
25%11%23%26%13%2
297
November1st to 10thDay
16%8%27%32%13%4
270
11th to 20thDay
15%14%35%26%10%
270
21st to endDay
21%11%31%20%13%4
270
December1st to 10thDay
26%20%25%22%6%1
270
11th to 20thDay
21%18%29%19%12%1
270
21st to endDay
25%20%31%21%4
297
January1st to 10thNight
22%17%30%26%5%
950
11th to 20thNight
26%16%30%23%4
753
21st to endNight
21%12%38%27%3
792
February1st to 10thNight
26%12%32%26%4
720
11th to 20thNight
29%13%33%22%3
703
21st to endNight
30%15%32%22%2
592
March1st to 10thNight
21%12%32%29%6%
720
11th to 20thNight
22%10%33%27%8%1
720
21st to endNight
20%12%29%30%9%
702
April1st to 10thNight
13%10%34%34%9%
540
11th to 20thNight
18%9%32%30%11%1
533
21st to endNight
16%9%28%35%11%1
540
May1st to 10thNight
12%429%35%18%1
540
11th to 20thNight
11%423%35%22%5%
531
21st to endNight
8%214%39%32%5%
584
June1st to 10thNight
9%314%35%34%5%
540
11th to 20thNight
5%110%37%40%6%
540
21st to endNight
6%110%39%37%8%
540
July1st to 10thNight
10%26%30%41%11%
525
11th to 20thNight
7%26%29%44%11%
522
21st to endNight
7%28%28%46%10%
591
August1st to 10thNight
8%1431%48%7%
537
11th to 20thNight
7%38%38%38%6%
534
21st to endNight
10%1431%44%10%
594
September1st to 10thNight
12%110%28%43%5%
558
11th to 20thNight
13%312%28%38%6%
720
21st to endNight
11%216%31%37%4
720
October1st to 10thNight
11%417%30%32%6%
720
11th to 20thNight
19%6%22%34%18%2
720
21st to endNight
18%7%27%30%17%2
792
November1st to 10thNight
14%6%21%38%19%2
740
11th to 20thNight
15%9%31%31%13%1
760
21st to endNight
19%10%27%32%11%1
760
December1st to 10thNight
28%11%28%26%6%
760
11th to 20thNight
22%8%31%31%7%1
760
21st to endNight
26%13%30%26%5%
840
Page generated at 2024-01-07 09:06:57. Version ac07

Copyright 2024 Attilla Danko


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