Mahogany Hammock
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mahogany Hammock clear sky chart from 2005-11-05 to 2018-01-12.

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
69%
16702
19%
48380
17%
16663
72%
16663
31%
30398

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
62%
763
19%
2472
19%
761
66%
761
29%
1472
January16th to endNight
61%
768
26%
2421
23%
768
67%
768
34%
1382
February1st to 15thNight
59%
701
27%
2107
23%
700
65%
700
36%
1228
February16th to endNight
69%
631
30%
1738
24%
631
74%
631
45%
970
March1st to 15thNight
65%
720
26%
1980
20%
720
70%
720
41%
1143
March16th to endNight
66%
768
28%
2112
24%
768
70%
768
43%
1178
April1st to 15thNight
76%
718
25%
1976
22%
718
78%
718
49%
1062
April16th to endNight
73%
720
26%
1836
18%
720
75%
720
46%
1062
May1st to 15thNight
80%
719
25%
1799
18%
719
81%
719
53%
991
May16th to endNight
74%
600
17%
1722
14%
600
75%
600
30%
1100
June1st to 15thNight
62%
540
9%
1620
7%
540
62%
540
16%
1224
June16th to endNight
78%
540
6%
1620
6%
540
78%
540
20%
1182
July1st to 15thNight
80%
510
5%
1530
5%
510
80%
510
23%
1049
July16th to endNight
85%
564
11%
1595
11%
531
85%
531
29%
1008
August1st to 15thNight
79%
599
10%
1669
9%
596
79%
596
26%
1143
August16th to endNight
70%
764
6%
2093
6%
764
70%
764
19%
1550
September1st to 15thNight
73%
720
5%
1980
5%
720
73%
720
18%
1484
September16th to endNight
63%
717
5%
1980
6%
717
63%
717
16%
1517
October1st to 15thNight
70%
720
14%
2070
15%
720
70%
720
23%
1428
October16th to endNight
60%
768
18%
2304
19%
768
62%
768
23%
1567
November1st to 15thNight
67%
760
25%
2281
23%
760
71%
760
35%
1356
November16th to endNight
64%
780
29%
2340
27%
780
69%
780
32%
1404
December1st to 15thNight
68%
780
25%
2431
24%
780
72%
780
32%
1437
December16th to endNight
73%
832
27%
2704
29%
832
75%
832
37%
1461

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
7%5%37%8%5%7%7%7%9%29%
48938
Night
5%4245%35%6%7%10%43%
48584
TransparencyDay
43%11%14%16%10%2
48639
Night
32%10%18%22%12%3
48387
SeeingDay
9%110%23%29%26%
6481
Night
7%111%30%34%14%
16710

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
8%437%446%6%7%10%35%
1710
16th to endDay
7%426%5%35%6%7%10%39%
1800
February1st to 15thDay
7%425%5%445%6%8%43%
1750
16th to endDay
42145%346%7%11%46%
1733
March1st to 15thDay
4425%6%46%7%8%10%40%
1980
16th to endDay
5%5%146%35%6%7%10%42%
2111
April1st to 15thDay
5%3145%36%8%8%12%40%
1972
16th to endDay
6%326%5%46%6%8%10%39%
2121
May1st to 15thDay
43245%46%6%7%11%43%
2152
16th to endDay
8%6%37%9%49%7%9%9%23%
2400
June1st to 15thDay
10%8%5%12%11%6%10%7%7%7%14%
2340
16th to endDay
7%7%411%10%6%10%9%8%9%14%
2340
July1st to 15thDay
6%6%39%11%6%11%10%9%9%15%
2340
16th to endDay
45%38%11%6%10%10%9%10%17%
2465
August1st to 15thDay
5%8%29%11%6%9%9%8%9%18%
2265
16th to endDay
8%8%310%11%6%9%9%7%8%14%
2104
September1st to 15thDay
8%9%310%11%7%9%9%7%9%13%
1980
16th to endDay
10%11%49%11%6%9%7%7%7%14%
1980
October1st to 15thDay
7%6%28%9%6%8%7%9%10%22%
1890
16th to endDay
12%6%37%8%5%5%7%6%6%29%
1920
November1st to 15thDay
6%5%27%5%46%5%5%7%41%
1907
16th to endDay
7%436%5%46%5%6%8%41%
1950
December1st to 15thDay
8%435%6%36%5%7%9%39%
1856
16th to endDay
44245%46%7%8%12%38%
1872
January1st to 15thNight
6%5%25%5%346%7%11%42%
2472
16th to endNight
4415%435%5%6%9%48%
2421
February1st to 15thNight
7%325%424448%51%
2103
16th to endNight
3313325%5%6%8%57%
1738
March1st to 15thNight
3313435%5%6%7%55%
1980
16th to endNight
322343446%8%56%
2112
April1st to 15thNight
221342436%9%60%
1976
16th to endNight
43133245%7%10%53%
1836
May1st to 15thNight
21232345%11%60%
1799
16th to endNight
6%424446%6%7%10%40%
1721
June1st to 15thNight
11%6%37%9%46%7%9%9%24%
1620
16th to endNight
4325%7%5%8%10%10%13%30%
1620
July1st to 15thNight
3335%447%8%8%13%37%
1620
16th to endNight
2314446%8%9%15%39%
1703
August1st to 15thNight
3325%6%36%6%10%14%37%
1680
16th to endNight
7%426%7%47%8%8%12%30%
2093
September1st to 15thNight
4426%6%48%10%11%13%27%
1980
16th to endNight
6%6%38%10%46%6%10%10%26%
1980
October1st to 15thNight
5%426%6%5%6%7%9%12%33%
2070
16th to endNight
10%6%36%6%35%6%6%9%34%
2304
November1st to 15thNight
4425%435%5%6%9%48%
2281
16th to endNight
6%4245%25%5%5%8%47%
2340
December1st to 15thNight
5%324435%7%6%10%46%
2431
16th to endNight
43233245%7%11%51%
2704

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
38%8%14%20%12%5%
1711
16th to endDay
35%8%13%21%17%4
1800
February1st to 15thDay
34%5%10%24%18%6%
1752
16th to endDay
25%5%14%30%18%5%
1733
March1st to 15thDay
31%8%14%24%18%3
1980
16th to endDay
29%8%14%24%18%5%
2112
April1st to 15thDay
28%6%18%27%15%2
1972
16th to endDay
32%8%14%22%18%3
2121
May1st to 15thDay
30%10%14%24%14%5%
2152
16th to endDay
49%11%15%17%5%
2404
June1st to 15thDay
62%13%12%10%1
2340
16th to endDay
59%14%17%7%
2340
July1st to 15thDay
53%20%18%6%
2201
16th to endDay
49%20%19%10%
2310
August1st to 15thDay
51%16%18%12%1
2252
16th to endDay
58%16%15%8%
2104
September1st to 15thDay
60%16%14%7%
1980
16th to endDay
63%14%12%7%1
1980
October1st to 15thDay
50%12%14%12%7%2
1890
16th to endDay
49%8%9%14%13%5%
1920
November1st to 15thDay
38%6%11%17%20%4
1907
16th to endDay
36%7%10%15%23%6%
1950
December1st to 15thDay
37%7%12%18%19%4
1856
16th to endDay
31%8%12%24%19%2
1872
January1st to 15thNight
33%8%17%24%12%3
2472
16th to endNight
30%6%13%28%16%4
2421
February1st to 15thNight
30%6%9%26%18%8%
2112
16th to endNight
23%7%16%24%21%7%
1738
March1st to 15thNight
26%6%12%29%19%4
1980
16th to endNight
24%7%15%27%20%4
2112
April1st to 15thNight
20%6%18%31%19%3
1976
16th to endNight
23%7%15%28%22%2
1836
May1st to 15thNight
18%7%16%34%18%4
1800
16th to endNight
35%9%19%25%10%
1723
June1st to 15thNight
49%13%20%12%3
1620
16th to endNight
39%18%29%10%1
1620
July1st to 15thNight
34%17%35%11%
1530
16th to endNight
26%17%37%16%1
1595
August1st to 15thNight
32%18%27%21%
1669
16th to endNight
42%17%27%12%
2093
September1st to 15thNight
41%19%26%11%1
1980
16th to endNight
46%17%22%11%2
1980
October1st to 15thNight
38%13%21%17%7%1
2070
16th to endNight
42%9%12%18%12%5%
2304
November1st to 15thNight
31%7%13%23%20%4
2281
16th to endNight
33%7%11%18%22%6%
2340
December1st to 15thNight
31%8%14%22%20%3
2431
16th to endNight
25%7%13%30%19%2
2704

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
16%434%30%13%
123
16th to endDay
12%13%20%35%14%3
96
February1st to 15thDay
5%5%25%37%21%4
90
16th to endDay
5%222%39%29%
234
March1st to 15thDay
4122%41%27%2
270
16th to endDay
6%119%35%28%7%
288
April1st to 15thDay
414%40%30%9%
270
16th to endDay
9%12%32%35%8%
270
May1st to 15thDay
5%9%28%36%20%
288
16th to endDay
9%6%19%32%32%
331
June1st to 15thDay
15%18%18%24%32%
315
16th to endDay
7%111%24%55%
315
July1st to 15thDay
7%5%33%52%
305
16th to endDay
7%19%25%56%
326
August1st to 15thDay
7%46%30%51%
313
16th to endDay
12%111%27%46%
332
September1st to 15thDay
9%310%23%53%
315
16th to endDay
13%17%26%49%
314
October1st to 15thDay
7%8%25%40%17%
315
16th to endDay
13%114%29%27%12%
336
November1st to 15thDay
8%11%33%33%12%
325
16th to endDay
8%122%34%29%3
330
December1st to 15thDay
13%14%30%35%6%
236
16th to endDay
6%7%32%38%13%
144
January1st to 15thNight
9%318%34%30%3
765
16th to endNight
6%322%42%24%
768
February1st to 15thNight
9%22%41%23%
704
16th to endNight
5%119%46%26%
631
March1st to 15thNight
6%120%43%25%1
720
16th to endNight
4119%44%28%1
768
April1st to 15thNight
412%45%34%1
718
16th to endNight
6%112%48%29%2
720
May1st to 15thNight
39%43%37%5%
720
16th to endNight
8%7%23%46%13%
602
June1st to 15thNight
14%5%15%39%24%
540
16th to endNight
4210%42%39%
540
July1st to 15thNight
425%43%43%
510
16th to endNight
318%35%51%
564
August1st to 15thNight
5%8%42%42%
599
16th to endNight
8%49%39%37%
764
September1st to 15thNight
7%310%34%43%
720
16th to endNight
10%312%38%34%
717
October1st to 15thNight
7%8%26%44%12%
720
16th to endNight
14%112%29%32%10%
768
November1st to 15thNight
7%16%35%34%4
760
16th to endNight
8%117%38%31%3
780
December1st to 15thNight
7%114%42%31%2
780
16th to endNight
6%113%34%38%5%
832
Page generated at 2018-01-12 22:01:36. Version ac04

Copyright 2018 A. Danko


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