Houma
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Houma clear sky chart from 2005-11-05 to 2017-09-18.

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
61%
15110
23%
46769
19%
15065
65%
15065
32%
27729

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
44%
900
22%
2327
11%
895
51%
895
32%
1515
January16th to endNight
40%
840
25%
2376
13%
840
47%
840
28%
1519
February1st to 15thNight
44%
704
26%
2111
15%
700
51%
700
31%
1276
February16th to endNight
38%
631
22%
1893
13%
631
45%
631
29%
1182
March1st to 15thNight
45%
564
25%
2004
18%
564
54%
564
26%
1173
March16th to endNight
56%
576
23%
2067
20%
576
62%
576
31%
1121
April1st to 15thNight
53%
539
26%
1797
21%
539
62%
539
33%
1009
April16th to endNight
56%
540
26%
1800
25%
540
63%
540
34%
1000
May1st to 15thNight
67%
539
21%
1799
23%
539
71%
539
35%
990
May16th to endNight
75%
561
22%
1870
25%
561
77%
561
36%
1018
June1st to 15thNight
78%
540
14%
1755
18%
540
79%
540
31%
1046
June16th to endNight
76%
540
14%
1620
15%
540
76%
540
29%
1022
July1st to 15thNight
81%
510
13%
1530
16%
510
81%
510
32%
932
July16th to endNight
77%
564
9%
1719
13%
531
77%
531
25%
1105
August1st to 15thNight
84%
539
14%
1788
18%
536
84%
536
35%
1006
August16th to endNight
77%
573
13%
1910
16%
573
77%
573
25%
1209
September1st to 15thNight
74%
540
18%
1800
19%
540
75%
540
27%
1091
September16th to endNight
76%
614
27%
1793
26%
614
76%
614
34%
1088
October1st to 15thNight
77%
660
30%
1950
27%
660
79%
660
48%
999
October16th to endNight
63%
704
33%
2112
27%
704
68%
704
42%
1131
November1st to 15thNight
64%
700
32%
2100
29%
700
68%
700
37%
1206
November16th to endNight
55%
720
34%
2160
26%
720
64%
720
38%
1210
December1st to 15thNight
52%
720
26%
2160
20%
720
57%
720
29%
1331
December16th to endNight
41%
792
20%
2328
14%
792
46%
792
24%
1550

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
10%6%36%6%46%6%6%8%35%
47994
Night
8%42442446%8%48%
46981
TransparencyDay
42%8%12%16%14%5%
47708
Night
32%7%15%20%16%7%
46772
SeeingDay
11%213%23%26%22%
5251
Night
10%416%30%28%10%
15113

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
14%5%25%435%447%41%
1611
16th to endDay
17%6%34423335%43%
1842
February1st to 15thDay
11%6%25%4245%5%7%44%
1750
16th to endDay
15%7%2442435%7%40%
1580
March1st to 15thDay
13%6%26%42445%7%40%
1965
16th to endDay
9%5%25%4345%6%8%43%
2155
April1st to 15thDay
10%5%34425%5%6%10%40%
2151
16th to endDay
9%5%25%5%36%5%5%9%40%
2160
May1st to 15thDay
8%5%25%5%36%5%6%10%39%
2151
16th to endDay
8%435%5%47%6%7%9%37%
2244
June1st to 15thDay
8%7%37%9%5%9%7%8%9%23%
2201
16th to endDay
7%5%37%9%5%10%9%9%10%21%
2340
July1st to 15thDay
8%6%48%9%6%9%9%8%9%19%
2340
16th to endDay
10%7%49%9%5%9%8%7%8%19%
2327
August1st to 15thDay
9%5%39%9%6%9%8%9%11%17%
2160
16th to endDay
10%7%48%9%5%8%8%6%8%22%
2292
September1st to 15thDay
12%6%27%8%47%7%6%9%28%
2160
16th to endDay
11%7%35%8%45%6%6%7%33%
1879
October1st to 15thDay
7%3245%3445%8%51%
1678
16th to endDay
7%424434348%53%
1760
November1st to 15thDay
8%5%35%42335%7%49%
1758
16th to endDay
8%3145%34336%53%
1800
December1st to 15thDay
13%7%3443446%7%41%
1800
16th to endDay
19%6%36%5%24447%34%
1890
January1st to 15thNight
14%5%2442435%7%45%
2327
16th to endNight
15%6%34423447%43%
2376
February1st to 15thNight
12%5%24324348%47%
2103
16th to endNight
15%7%23323346%47%
1893
March1st to 15thNight
13%5%1442435%8%46%
2004
16th to endNight
8%424324448%50%
2067
April1st to 15thNight
9%32442445%6%52%
1797
16th to endNight
6%425%42446%8%50%
1800
May1st to 15thNight
5%3234245%7%10%49%
1799
16th to endNight
5%31342446%9%53%
1869
June1st to 15thNight
5%3235%35%5%8%11%45%
1755
16th to endNight
6%4235%37%5%8%11%42%
1620
July1st to 15thNight
43244246%9%14%43%
1620
16th to endNight
4336%426%8%9%12%37%
1838
August1st to 15thNight
22134445%8%15%47%
1800
16th to endNight
6%325%5%347%8%11%40%
1910
September1st to 15thNight
6%3245%26%5%7%11%43%
1800
16th to endNight
7%4234345%7%9%48%
1793
October1st to 15thNight
4213313348%62%
1950
16th to endNight
8%323313446%58%
2112
November1st to 15thNight
10%324423447%53%
2100
16th to endNight
7%414324445%57%
2160
December1st to 15thNight
12%5%2442445%6%47%
2160
16th to endNight
14%7%35%6%3445%7%38%
2328

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
41%5%8%17%18%9%
1612
16th to endDay
43%46%16%19%9%
1842
February1st to 15thDay
37%6%9%15%22%8%
1752
16th to endDay
42%48%19%18%6%
1580
March1st to 15thDay
40%6%10%20%16%5%
1965
16th to endDay
36%6%11%21%18%5%
2157
April1st to 15thDay
36%7%11%17%16%8%
2151
16th to endDay
37%7%12%22%14%5%
2160
May1st to 15thDay
37%7%13%21%12%7%
2151
16th to endDay
38%8%13%22%15%1
2248
June1st to 15thDay
50%11%11%16%8%
2201
16th to endDay
49%12%18%13%6%
2340
July1st to 15thDay
53%13%17%12%2
2201
16th to endDay
57%13%16%10%2
2183
August1st to 15thDay
52%16%17%10%1
2148
16th to endDay
54%13%16%9%5%1
2292
September1st to 15thDay
47%12%15%12%9%2
2160
16th to endDay
46%7%13%12%15%4
1879
October1st to 15thDay
29%5%11%17%21%13%
1678
16th to endDay
29%36%17%26%15%
1760
November1st to 15thDay
32%49%22%22%8%
1758
16th to endDay
30%48%16%24%15%
1800
December1st to 15thDay
40%6%10%21%15%5%
1800
16th to endDay
47%49%18%14%5%
1890
January1st to 15thNight
38%49%15%21%10%
2327
16th to endNight
40%38%16%18%12%
2376
February1st to 15thNight
35%48%19%20%11%
2112
16th to endNight
38%49%14%20%12%
1893
March1st to 15thNight
36%5%11%19%19%7%
2004
16th to endNight
31%5%14%20%21%7%
2067
April1st to 15thNight
31%5%13%21%17%10%
1797
16th to endNight
30%5%12%25%18%7%
1800
May1st to 15thNight
27%7%14%26%15%7%
1800
16th to endNight
26%7%17%26%20%1
1871
June1st to 15thNight
30%10%17%25%15%
1755
16th to endNight
34%10%24%21%8%
1620
July1st to 15thNight
27%13%32%22%4
1530
16th to endNight
31%16%31%17%3
1719
August1st to 15thNight
23%12%34%24%4
1788
16th to endNight
33%13%27%17%5%2
1910
September1st to 15thNight
33%10%21%17%12%4
1800
16th to endNight
29%9%17%20%16%6%
1793
October1st to 15thNight
20%5%13%21%22%16%
1950
16th to endNight
26%37%17%25%19%
2112
November1st to 15thNight
30%48%22%24%8%
2100
16th to endNight
28%5%7%17%24%16%
2160
December1st to 15thNight
37%5%10%24%16%7%
2160
16th to endNight
44%5%10%18%14%7%
2328

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
20%6%32%30%11%
90
16th to endDay
16%10%46%19%6%
96
February1st to 15thDay
415%32%34%12%1
90
16th to endDay
9%8%39%29%12%
81
March1st to 15thDay
26%8%34%22%7%
90
16th to endDay
15%5%25%26%24%2
141
April1st to 15thDay
16%5%21%33%21%1
270
16th to endDay
11%320%33%26%5%
270
May1st to 15thDay
11%417%34%25%7%
288
16th to endDay
7%112%29%28%20%
331
June1st to 15thDay
12%15%24%30%25%
356
16th to endDay
8%17%25%30%26%
495
July1st to 15thDay
6%317%30%40%
475
16th to endDay
8%111%33%44%
376
August1st to 15thDay
10%36%28%51%
313
16th to endDay
10%6%14%31%37%
332
September1st to 15thDay
11%5%19%29%32%
315
16th to endDay
13%420%37%22%
262
October1st to 15thDay
212%33%37%13%
118
16th to endDay
13%217%32%23%10%
96
November1st to 15thDay
23%122%30%18%4
90
16th to endDay
7%8%31%30%16%5%
90
December1st to 15thDay
17%8%33%25%10%4
90
16th to endDay
26%8%28%25%12%
96
January1st to 15thNight
16%7%26%40%9%
900
16th to endNight
17%9%27%35%9%
840
February1st to 15thNight
14%7%29%35%12%1
704
16th to endNight
18%8%30%33%8%
631
March1st to 15thNight
15%5%28%35%14%
564
16th to endNight
9%6%22%35%25%1
576
April1st to 15thNight
10%5%23%39%19%
539
16th to endNight
8%325%36%23%2
540
May1st to 15thNight
6%117%43%29%1
540
16th to endNight
6%19%34%39%8%
563
June1st to 15thNight
6%221%56%12%
540
16th to endNight
7%415%46%24%
540
July1st to 15thNight
418%46%38%
510
16th to endNight
418%46%38%
564
August1st to 15thNight
37%41%47%
539
16th to endNight
8%310%45%31%
573
September1st to 15thNight
9%313%46%27%
540
16th to endNight
9%423%49%12%
614
October1st to 15thNight
5%9%36%39%7%
660
16th to endNight
9%317%33%28%6%
704
November1st to 15thNight
11%214%41%25%5%
700
16th to endNight
10%5%23%39%20%2
720
December1st to 15thNight
14%7%19%37%19%
720
16th to endNight
16%7%28%31%14%1
792
Page generated at 2017-09-19 06:32:27. Version ac04

Copyright 2017 A. Danko


Houma Clear Sky Chart | Charts Home