Memphis
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Memphis clear sky chart from 2005-11-06 to 2024-03-28.

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
47%
24352
24%
80253
18%
24243
55%
24243
28%
47748

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
26%
944
24%
4183
10%
926
37%
926
18%
2527
January11th to 20thNight
25%
950
25%
3951
8%
930
35%
930
17%
2354
January21st to endNight
27%
1040
18%
4455
9%
1023
39%
1023
19%
2713
February1st to 10thNight
26%
823
19%
2343
8%
823
34%
823
23%
1592
February11th to 20thNight
25%
743
20%
2219
10%
740
32%
740
22%
1465
February21st to endNight
23%
628
21%
1884
8%
628
32%
628
21%
1248
March1st to 10thNight
32%
751
21%
2271
11%
751
40%
751
26%
1431
March11th to 20thNight
29%
570
19%
2090
12%
570
39%
570
19%
1338
March21st to endNight
33%
615
19%
2127
13%
615
42%
615
23%
1331
April1st to 10thNight
37%
540
25%
1800
16%
540
50%
540
29%
1046
April11th to 20thNight
40%
533
27%
1775
21%
533
54%
533
30%
1019
April21st to endNight
42%
540
26%
1800
19%
540
55%
540
30%
1059
May1st to 10thNight
49%
540
20%
1800
17%
540
56%
540
32%
1028
May11th to 20thNight
51%
531
21%
1657
18%
531
56%
531
28%
1031
May21st to endNight
63%
583
22%
1608
17%
582
67%
582
32%
1015
June1st to 10thNight
68%
540
23%
1440
19%
540
70%
540
37%
886
June11th to 20thNight
80%
540
29%
1440
25%
540
82%
540
53%
758
June21st to endNight
76%
540
27%
1440
22%
540
78%
540
48%
809
July1st to 10thNight
76%
525
20%
1400
18%
525
77%
525
41%
834
July11th to 20thNight
74%
522
21%
1498
20%
522
76%
522
38%
879
July21st to endNight
81%
591
25%
1673
29%
558
81%
558
43%
908
August1st to 10thNight
81%
537
23%
1752
27%
534
83%
534
41%
898
August11th to 20thNight
76%
534
22%
1776
27%
534
77%
534
32%
1010
August21st to endNight
75%
594
24%
1980
29%
594
75%
594
33%
1110
September1st to 10thNight
72%
540
27%
1800
29%
540
74%
540
34%
986
September11th to 20thNight
68%
570
29%
1830
29%
570
71%
570
34%
1046
September21st to endNight
63%
720
32%
1980
24%
720
67%
720
43%
1108
October1st to 10thNight
64%
720
32%
2098
27%
720
67%
720
47%
1095
October11th to 20thNight
52%
720
33%
2160
23%
720
62%
720
38%
1211
October21st to endNight
45%
792
29%
2376
21%
792
53%
792
31%
1440
November1st to 10thNight
52%
740
31%
2347
25%
740
61%
740
37%
1273
November11th to 20thNight
43%
760
29%
2470
21%
760
55%
760
35%
1343
November21st to endNight
40%
760
27%
2470
19%
760
50%
760
29%
1458
December1st to 10thNight
32%
788
25%
2498
14%
788
45%
788
25%
1580
December11th to 20thNight
36%
948
24%
3122
12%
948
45%
948
25%
1922
December21st to endNight
28%
1040
12%
4740
9%
1026
37%
1026
15%
2997

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%35%5%35%5%5%7%44%
78927
Night
13%5%2443445%7%48%
81104
TransparencyDay
39%7%11%22%18%4
78642
Night
35%6%10%23%21%5%
80911
SeeingDay
15%8%22%25%21%10%
14405
Night
15%7%25%31%19%3
24371

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%13%46%42323444%
2659
11th to 20thDay
21%8%25%5%2333442%
2850
21st to endDay
22%11%35%42334440%
3135
February1st to 10thDay
20%8%47%424336%39%
1834
11th to 20thDay
20%8%36%5%34346%39%
1848
21st to endDay
25%8%36%5%33445%36%
1570
March1st to 10thDay
17%8%36%5%34446%41%
1924
11th to 20thDay
19%9%37%6%35%44436%
2090
21st to endDay
17%8%36%6%345%6%7%36%
2381
April1st to 10thDay
12%6%35%5%3446%7%45%
2160
11th to 20thDay
16%6%25%42445%7%45%
2134
21st to endDay
15%6%36%5%3445%7%42%
2160
May1st to 10thDay
14%5%35%6%35%45%7%42%
2160
11th to 20thDay
11%6%25%5%346%6%9%44%
2235
21st to endDay
8%5%35%7%47%7%7%10%38%
2663
June1st to 10thDay
8%5%36%5%36%6%8%9%44%
2520
11th to 20thDay
4325%6%35%6%7%10%49%
2520
21st to endDay
5%3245%36%6%8%10%49%
2520
July1st to 10thDay
7%5%35%7%46%7%8%11%36%
2520
11th to 20thDay
7%435%5%47%7%9%10%40%
2408
21st to endDay
7%435%5%46%7%8%10%42%
2546
August1st to 10thDay
6%426%5%46%7%9%11%40%
2176
11th to 20thDay
8%425%5%36%6%7%9%43%
2125
21st to endDay
9%5%25%5%46%6%6%9%44%
2376
September1st to 10thDay
9%426%6%45%7%5%9%44%
2160
11th to 20thDay
11%5%25%5%35%5%6%8%46%
2111
21st to endDay
11%5%14423346%57%
1980
October1st to 10thDay
7%424434346%57%
1858
11th to 20thDay
13%5%2333335%7%54%
1800
21st to endDay
18%6%2332334452%
1980
November1st to 10thDay
13%5%23223235%60%
1726
11th to 20thDay
13%5%34423346%52%
1710
21st to endDay
19%6%35%5%24446%43%
1710
December1st to 10thDay
21%8%35%5%24445%40%
1677
11th to 20thDay
15%7%45%5%34435%44%
1918
21st to endDay
15%11%37%5%445%5%6%35%
2783
January1st to 10thNight
19%8%25%42434445%
4291
11th to 20thNight
19%6%35%33433447%
4120
21st to endNight
24%8%2432333445%
4532
February1st to 10thNight
21%7%36%5%23345%41%
2343
11th to 20thNight
19%7%45%5%24335%43%
2218
21st to endNight
20%8%46%434335%41%
1884
March1st to 10thNight
17%7%25%433445%46%
2271
11th to 20thNight
18%7%36%5%34346%42%
2090
21st to endNight
16%6%25%6%35%5%5%6%42%
2127
April1st to 10thNight
11%5%245%3445%8%49%
1800
11th to 20thNight
14%5%2443435%6%51%
1775
21st to endNight
12%5%25%4245%5%6%50%
1800
May1st to 10thNight
13%6%24414448%50%
1800
11th to 20thNight
11%6%26%5%45%5%6%7%45%
1656
21st to endNight
5%5%25%6%45%6%8%11%43%
1608
June1st to 10thNight
7%3245%46%47%10%47%
1440
11th to 20thNight
221332447%10%62%
1440
21st to endNight
32224346%7%12%55%
1440
July1st to 10thNight
33246%35%6%7%13%49%
1440
11th to 20thNight
6%424435%46%11%50%
1547
21st to endNight
43234345%6%11%55%
1772
August1st to 10thNight
4223425%5%7%10%56%
1762
11th to 20thNight
5%4245%36%5%8%11%47%
1776
21st to endNight
6%325%5%35%5%7%10%49%
1980
September1st to 10thNight
8%425%42445%7%54%
1800
11th to 20thNight
9%5%343246%5%7%52%
1830
21st to endNight
9%424423336%58%
1980
October1st to 10thNight
7%324323447%61%
2098
11th to 20thNight
11%425%312347%58%
2160
21st to endNight
18%5%2432333452%
2376
November1st to 10thNight
11%323433446%57%
2347
11th to 20thNight
11%424324446%54%
2470
21st to endNight
15%5%24434446%49%
2470
December1st to 10thNight
17%8%35%423345%46%
2498
11th to 20thNight
17%6%34433345%48%
3279
21st to endNight
16%8%36%6%45%5%5%6%37%
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
46%35%23%20%3
2660
11th to 20thDay
45%5%8%22%19%1
2850
21st to endDay
49%37%19%20%2
3135
February1st to 10thDay
49%47%22%15%2
1834
11th to 20thDay
48%5%7%17%18%5%
1858
21st to endDay
52%48%15%16%6%
1570
March1st to 10thDay
45%5%8%17%17%8%
1924
11th to 20thDay
51%6%6%18%16%2
2090
21st to endDay
47%5%11%23%13%1
2381
April1st to 10thDay
39%6%9%24%20%2
2160
11th to 20thDay
39%5%8%23%20%5%
2134
21st to endDay
42%5%9%24%18%1
2160
May1st to 10thDay
41%7%11%21%17%2
2160
11th to 20thDay
36%9%15%22%16%2
2239
21st to endDay
39%10%15%25%10%2
2663
June1st to 10thDay
34%9%12%24%19%1
2520
11th to 20thDay
28%8%14%29%18%4
2520
21st to endDay
27%9%13%27%19%5%
2520
July1st to 10thDay
36%12%16%21%12%3
2451
11th to 20thDay
33%12%17%22%11%4
2335
21st to endDay
32%11%17%28%10%1
2405
August1st to 10thDay
32%10%20%25%13%1
2162
11th to 20thDay
34%10%15%24%15%3
2125
21st to endDay
35%7%15%23%15%4
2376
September1st to 10thDay
35%9%11%24%17%5%
2160
11th to 20thDay
36%7%10%17%24%6%
2111
21st to endDay
29%410%23%27%8%
1980
October1st to 10thDay
29%411%24%23%10%
1858
11th to 20thDay
30%5%7%22%28%8%
1800
21st to endDay
37%46%22%24%8%
1980
November1st to 10thDay
29%37%26%25%9%
1726
11th to 20thDay
34%49%21%25%8%
1710
21st to endDay
43%47%19%23%4
1710
December1st to 10thDay
47%5%8%18%17%4
1677
11th to 20thDay
44%37%19%22%4
1915
21st to endDay
47%5%11%21%13%2
2783
January1st to 10thNight
43%46%21%23%2
4291
11th to 20thNight
42%5%8%21%20%4
4120
21st to endNight
43%38%23%20%3
4532
February1st to 10thNight
48%39%17%20%3
2343
11th to 20thNight
45%47%21%17%6%
2219
21st to endNight
46%48%16%20%7%
1884
March1st to 10thNight
40%5%9%15%20%11%
2271
11th to 20thNight
45%6%8%19%18%4
2090
21st to endNight
41%6%11%22%17%3
2127
April1st to 10thNight
34%6%11%24%20%5%
1800
11th to 20thNight
34%5%7%22%24%7%
1775
21st to endNight
35%6%10%25%22%3
1800
May1st to 10thNight
33%5%14%23%19%5%
1800
11th to 20thNight
37%8%13%22%18%2
1657
21st to endNight
33%10%13%27%15%2
1609
June1st to 10thNight
29%10%14%23%23%2
1440
11th to 20thNight
17%8%15%31%24%5%
1440
21st to endNight
20%9%16%28%22%5%
1440
July1st to 10thNight
24%11%20%27%15%3
1400
11th to 20thNight
27%10%19%27%12%6%
1498
21st to endNight
22%9%19%33%16%1
1673
August1st to 10thNight
21%9%20%34%16%
1752
11th to 20thNight
28%10%17%26%17%3
1776
21st to endNight
29%8%15%25%17%6%
1980
September1st to 10thNight
29%7%10%24%23%7%
1800
11th to 20thNight
31%7%10%19%27%6%
1830
21st to endNight
28%39%25%26%10%
1980
October1st to 10thNight
23%5%9%28%25%11%
2098
11th to 20thNight
28%5%6%20%30%11%
2160
21st to endNight
37%46%19%26%9%
2376
November1st to 10thNight
29%47%23%28%9%
2347
11th to 20thNight
30%48%21%26%10%
2470
21st to endNight
36%47%21%25%6%
2470
December1st to 10thNight
42%49%22%18%5%
2498
11th to 20thNight
39%47%22%23%4
3281
21st to endNight
44%7%11%18%15%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
23%16%39%14%7%1
270
11th to 20thDay
30%16%35%14%4
270
21st to endDay
22%18%40%16%31
297
February1st to 10thDay
24%16%38%13%7%1
270
11th to 20thDay
34%19%31%13%3
270
21st to endDay
40%19%28%8%5%
225
March1st to 10thDay
24%16%34%20%5%1
270
11th to 20thDay
26%20%30%23%2
270
21st to endDay
24%17%32%20%6%1
411
April1st to 10thDay
16%15%34%24%10%1
420
11th to 20thDay
21%12%30%24%9%3
412
21st to endDay
22%10%30%23%12%3
420
May1st to 10thDay
17%12%27%26%15%2
423
11th to 20thDay
13%6%24%26%22%9%
447
21st to endDay
10%422%30%22%11%
617
June1st to 10thDay
11%314%27%29%16%
630
11th to 20thDay
3215%35%33%13%
630
21st to endDay
5%17%37%27%14%
630
July1st to 10thDay
6%210%28%30%23%
621
11th to 20thDay
6%212%23%37%20%
618
21st to endDay
5%29%30%35%19%
684
August1st to 10thDay
7%211%27%37%16%
474
11th to 20thDay
12%18%31%33%15%
439
21st to endDay
13%25%20%35%25%
495
September1st to 10thDay
8%18%29%36%18%
450
11th to 20thDay
7%214%21%35%21%
450
21st to endDay
14%314%32%24%13%
450
October1st to 10thDay
9%320%33%27%8%
328
11th to 20thDay
12%9%32%30%13%4
270
21st to endDay
24%10%29%24%10%3
297
November1st to 10thDay
18%7%23%33%16%3
270
11th to 20thDay
8%17%35%27%12%1
270
21st to endDay
25%10%31%19%13%2
270
December1st to 10thDay
26%19%29%20%6%1
270
11th to 20thDay
24%14%31%21%8%1
270
21st to endDay
26%16%36%16%5%1
297
January1st to 10thNight
23%11%35%26%5%
950
11th to 20thNight
24%14%34%25%3
950
21st to endNight
22%11%38%27%2
1045
February1st to 10thNight
26%10%34%26%4
823
11th to 20thNight
24%14%34%25%3
743
21st to endNight
25%15%35%22%3
628
March1st to 10thNight
19%13%33%30%5%
751
11th to 20thNight
22%11%35%27%5%1
570
21st to endNight
20%10%32%27%11%
615
April1st to 10thNight
13%10%37%30%10%
540
11th to 20thNight
15%9%32%31%12%1
533
21st to endNight
13%7%34%34%9%2
540
May1st to 10thNight
15%5%27%38%13%2
540
11th to 20thNight
14%6%23%36%18%3
531
21st to endNight
5%218%40%30%5%
584
June1st to 10thNight
8%214%35%34%7%
540
11th to 20thNight
2111%40%45%2
540
21st to endNight
4112%38%39%6%
540
July1st to 10thNight
2110%31%45%10%
525
11th to 20thNight
6%210%27%43%13%
522
21st to endNight
416%32%44%12%
591
August1st to 10thNight
415%31%50%9%
537
11th to 20thNight
6%27%35%44%6%
534
21st to endNight
7%16%29%48%9%
594
September1st to 10thNight
8%27%35%44%5%
540
11th to 20thNight
11%212%30%38%8%
570
21st to endNight
10%415%34%33%4
720
October1st to 10thNight
7%418%34%33%4
720
11th to 20thNight
14%6%25%36%18%2
720
21st to endNight
19%7%24%33%15%1
792
November1st to 10thNight
12%5%26%36%19%2
740
11th to 20thNight
13%7%32%36%11%
760
21st to endNight
16%10%31%29%12%1
760
December1st to 10thNight
21%10%32%30%7%
788
11th to 20thNight
23%9%28%33%7%
950
21st to endNight
24%13%31%28%4
1045
Page generated at 2024-03-24 22:37:01. Version ac07

Copyright © 2024 Attilla Danko.


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