Murfreesboro
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Murfreesboro clear sky chart from 2005-11-05 to 2017-03-24.

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%
14726
22%
44998
16%
14683
52%
14683
27%
28400

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 15thNight
24%
720
20%
2327
11%
716
35%
716
19%
1567
January16th to endNight
23%
768
20%
2392
9%
768
34%
768
18%
1655
February1st to 15thNight
22%
704
17%
2112
8%
701
31%
701
20%
1440
February16th to endNight
21%
631
20%
1893
9%
631
30%
631
20%
1294
March1st to 15thNight
26%
720
18%
2145
10%
720
33%
720
21%
1472
March16th to endNight
35%
696
19%
1991
13%
696
40%
696
25%
1322
April1st to 15thNight
38%
494
26%
1647
17%
494
52%
494
30%
933
April16th to endNight
45%
495
24%
1617
16%
495
55%
495
30%
936
May1st to 15thNight
46%
494
21%
1485
13%
494
53%
494
27%
975
May16th to endNight
64%
513
18%
1539
14%
513
66%
513
30%
949
June1st to 15thNight
68%
495
20%
1482
14%
495
72%
495
35%
885
June16th to endNight
77%
495
22%
1320
17%
495
79%
495
43%
776
July1st to 15thNight
69%
465
17%
1265
15%
465
70%
465
34%
802
July16th to endNight
77%
522
17%
1469
16%
489
78%
489
35%
881
August1st to 15thNight
78%
494
21%
1580
23%
491
79%
491
34%
917
August16th to endNight
73%
525
20%
1750
25%
525
73%
525
30%
1040
September1st to 15thNight
62%
566
21%
1721
19%
566
65%
566
28%
1109
September16th to endNight
62%
657
27%
1815
22%
657
65%
657
33%
1136
October1st to 15thNight
55%
660
34%
1815
26%
660
61%
660
37%
1084
October16th to endNight
48%
704
30%
2181
25%
704
56%
704
33%
1266
November1st to 15thNight
47%
700
29%
2276
25%
700
55%
700
33%
1267
November16th to endNight
37%
720
25%
2340
18%
720
48%
720
27%
1414
December1st to 15thNight
29%
720
19%
2340
12%
720
38%
720
20%
1563
December16th to endNight
27%
768
20%
2496
12%
768
37%
768
18%
1717

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%25%5%35%5%5%7%39%
45930
Night
13%6%25%42445%7%44%
45188
TransparencyDay
42%7%10%19%15%3
45623
Night
39%5%10%21%18%4
44999
SeeingDay
14%7%19%22%22%12%
4750
Night
15%8%24%28%19%3
14729

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 15thDay
18%9%36%5%2433435%
1611
16th to endDay
19%7%35%42434439%
1830
February1st to 15thDay
17%10%37%6%2433435%
1750
16th to endDay
16%9%36%5%25%346%34%
1580
March1st to 15thDay
17%9%36%5%24435%36%
1815
16th to endDay
16%7%35%4245%6%6%35%
2085
April1st to 15thDay
12%6%25%4235%5%7%43%
1971
16th to endDay
11%6%25%5%25%45%6%42%
2013
May1st to 15thDay
16%5%34435%448%38%
2136
16th to endDay
10%6%35%6%45%5%5%7%39%
2223
June1st to 15thDay
6%425%5%46%6%7%9%41%
2145
16th to endDay
4325%5%47%6%7%11%40%
2307
July1st to 15thDay
9%5%26%7%5%8%7%7%8%32%
2280
16th to endDay
7%426%7%48%6%7%10%32%
2283
August1st to 15thDay
5%415%7%47%7%7%9%37%
2036
16th to endDay
10%5%25%7%5%6%7%7%8%33%
2100
September1st to 15thDay
13%6%36%6%37%6%5%6%33%
1897
16th to endDay
10%5%25%5%34446%46%
1815
October1st to 15thDay
12%423423335%52%
1815
16th to endDay
15%413323345%52%
1688
November1st to 15thDay
13%5%22313346%53%
1582
16th to endDay
16%5%25%323445%48%
1620
December1st to 15thDay
19%8%46%5%23346%33%
1620
16th to endDay
19%9%25%5%23335%37%
1728
January1st to 15thNight
16%9%27%5%23435%39%
2327
16th to endNight
17%8%36%5%34445%36%
2392
February1st to 15thNight
18%8%35%423245%38%
2103
16th to endNight
17%8%245%3445%5%37%
1893
March1st to 15thNight
16%6%25%5%35%45%7%37%
2145
16th to endNight
14%9%25%32445%6%41%
1991
April1st to 15thNight
12%413423347%50%
1647
16th to endNight
11%424424446%49%
1617
May1st to 15thNight
11%6%25%5%35%447%43%
1484
16th to endNight
6%4245%35%5%6%10%45%
1538
June1st to 15thNight
4325%5%4446%10%47%
1482
16th to endNight
22144245%8%11%51%
1320
July1st to 15thNight
10%4235%25%5%6%11%41%
1347
16th to endNight
43145%36%6%7%13%42%
1577
August1st to 15thNight
4323435%5%7%11%47%
1591
16th to endNight
7%425%4345%7%10%43%
1750
September1st to 15thNight
10%6%26%5%25%5%47%42%
1721
16th to endNight
10%425%5%33448%48%
1815
October1st to 15thNight
12%313422337%53%
1815
16th to endNight
15%5%23312335%52%
2181
November1st to 15thNight
12%424413336%53%
2276
16th to endNight
16%5%23323336%48%
2340
December1st to 15thNight
18%7%35%5%2345%5%37%
2340
16th to endNight
20%8%45%5%23335%36%
2496

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 15thDay
51%5%6%18%16%1
1612
16th to endDay
48%49%22%13%2
1830
February1st to 15thDay
52%47%19%13%2
1752
16th to endDay
50%49%19%12%2
1580
March1st to 15thDay
50%5%8%16%14%4
1815
16th to endDay
46%7%12%19%13%
2086
April1st to 15thDay
38%6%9%21%18%4
1971
16th to endDay
40%6%8%22%18%3
2013
May1st to 15thDay
44%7%10%21%13%2
2136
16th to endDay
42%8%13%21%11%2
2227
June1st to 15thDay
36%10%14%22%14%1
2145
16th to endDay
34%10%13%19%17%4
2307
July1st to 15thDay
43%11%16%14%9%3
2133
16th to endDay
41%11%18%18%9%1
2128
August1st to 15thDay
36%10%16%18%14%2
2023
16th to endDay
44%9%12%18%12%2
2100
September1st to 15thDay
46%9%10%16%12%4
1897
16th to endDay
37%6%10%18%23%3
1815
October1st to 15thDay
34%5%7%20%26%5%
1815
16th to endDay
34%47%20%27%6%
1688
November1st to 15thDay
33%46%21%26%7%
1582
16th to endDay
38%45%26%20%4
1620
December1st to 15thDay
51%46%20%12%3
1620
16th to endDay
49%5%11%18%13%1
1728
January1st to 15thNight
47%48%19%16%3
2327
16th to endNight
49%5%8%19%14%3
2392
February1st to 15thNight
48%311%20%14%2
2112
16th to endNight
48%49%20%15%2
1893
March1st to 15thNight
46%6%9%17%15%5%
2145
16th to endNight
43%5%11%24%14%1
1991
April1st to 15thNight
33%412%23%21%5%
1647
16th to endNight
33%5%9%24%23%4
1617
May1st to 15thNight
40%6%11%23%15%1
1485
16th to endNight
32%9%16%22%14%3
1540
June1st to 15thNight
31%6%14%29%15%1
1482
16th to endNight
23%10%17%28%14%5%
1320
July1st to 15thNight
32%9%18%21%13%3
1265
16th to endNight
28%10%20%24%13%2
1469
August1st to 15thNight
27%11%16%25%17%2
1580
16th to endNight
33%7%15%23%16%3
1750
September1st to 15thNight
38%7%13%18%17%4
1721
16th to endNight
35%5%6%20%25%6%
1815
October1st to 15thNight
30%5%7%19%27%8%
1815
16th to endNight
35%25%20%27%8%
2181
November1st to 15thNight
33%26%19%26%10%
2276
16th to endNight
38%47%21%22%4
2340
December1st to 15thNight
47%5%8%19%15%3
2340
16th to endNight
50%48%18%15%1
2496

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 15thDay
24%24%30%12%8%
90
16th to endDay
25%21%40%8%4
96
February1st to 15thDay
23%30%36%7%2
90
16th to endDay
28%22%29%17%2
81
March1st to 15thDay
22%26%36%9%3
105
16th to endDay
17%10%32%25%13%
260
April1st to 15thDay
13%14%30%25%12%2
210
16th to endDay
16%7%25%24%20%5%
210
May1st to 15thDay
17%8%28%21%15%7%
228
16th to endDay
16%316%26%19%17%
267
June1st to 15thDay
7%118%16%30%24%
255
16th to endDay
4214%32%26%20%
417
July1st to 15thDay
11%213%30%26%15%
372
16th to endDay
6%18%16%30%36%
270
August1st to 15thDay
9%7%19%37%25%
253
16th to endDay
15%5%20%38%19%
268
September1st to 15thDay
12%29%19%32%22%
255
16th to endDay
16%311%27%33%7%
254
October1st to 15thDay
14%224%23%27%6%
255
16th to endDay
19%5%19%31%19%4
148
November1st to 15thDay
14%12%20%37%14%1
90
16th to endDay
18%18%35%14%11%1
90
December1st to 15thDay
24%17%32%17%6%1
90
16th to endDay
20%22%37%16%2
96
January1st to 15thNight
22%19%29%23%4
720
16th to endNight
22%15%36%23%2
768
February1st to 15thNight
23%13%36%22%3
704
16th to endNight
23%16%35%21%2
631
March1st to 15thNight
20%14%35%24%4
720
16th to endNight
18%12%28%26%12%1
696
April1st to 15thNight
14%10%34%29%9%1
494
16th to endNight
13%7%31%33%11%1
495
May1st to 15thNight
13%5%28%30%21%
495
16th to endNight
7%117%38%27%6%
515
June1st to 15thNight
5%117%36%33%7%
495
16th to endNight
210%34%42%9%
495
July1st to 15thNight
10%19%35%36%6%
465
16th to endNight
49%26%44%14%
522
August1st to 15thNight
6%5%28%48%10%
494
16th to endNight
8%6%34%40%8%
525
September1st to 15thNight
12%212%27%38%6%
566
16th to endNight
12%215%29%37%2
657
October1st to 15thNight
13%5%18%29%27%5%
660
16th to endNight
18%6%23%31%18%2
704
November1st to 15thNight
14%8%25%28%19%3
700
16th to endNight
18%13%27%27%12%
720
December1st to 15thNight
24%11%30%24%8%
720
16th to endNight
26%14%28%25%4
768
Page generated at 2017-03-25 11:39:44. Version ac04

Copyright 2017 A. Danko


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