Anahuac Wildlife Refuge
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Anahuac Wildlife Refuge clear sky chart from 2005-11-05 to 2018-02-22.

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
58%
16023
23%
48833
19%
15976
62%
15976
30%
29813

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
38%
975
23%
2522
10%
970
45%
970
28%
1705
January16th to endNight
42%
1040
22%
2704
11%
1040
47%
1040
29%
1816
February1st to 15thNight
39%
888
21%
2416
10%
884
45%
884
26%
1638
February16th to endNight
36%
495
24%
1813
16%
495
46%
495
21%
1125
March1st to 15thNight
41%
540
24%
1980
18%
540
48%
540
22%
1211
March16th to endNight
54%
576
22%
2112
20%
576
59%
576
28%
1191
April1st to 15thNight
49%
539
22%
1908
19%
539
56%
539
27%
1135
April16th to endNight
49%
540
21%
1800
19%
540
55%
540
26%
1098
May1st to 15thNight
56%
539
19%
1787
19%
539
61%
539
28%
1089
May16th to endNight
70%
563
24%
1685
26%
561
73%
561
36%
974
June1st to 15thNight
85%
540
18%
1620
20%
540
85%
540
41%
887
June16th to endNight
74%
540
15%
1620
19%
540
74%
540
29%
1019
July1st to 15thNight
78%
510
16%
1530
19%
510
78%
510
31%
925
July16th to endNight
81%
564
17%
1594
21%
531
82%
531
33%
967
August1st to 15thNight
87%
539
24%
1658
28%
536
87%
536
47%
846
August16th to endNight
73%
573
14%
1910
16%
573
73%
573
24%
1235
September1st to 15thNight
75%
540
15%
1929
17%
540
76%
540
25%
1154
September16th to endNight
74%
537
25%
1980
30%
537
74%
537
26%
1156
October1st to 15thNight
79%
694
30%
2134
26%
694
80%
694
43%
1121
October16th to endNight
67%
768
36%
2304
27%
768
72%
768
46%
1189
November1st to 15thNight
63%
760
27%
2280
23%
760
66%
760
36%
1327
November16th to endNight
57%
780
35%
2340
25%
780
65%
780
38%
1323
December1st to 15thNight
47%
943
24%
2503
15%
943
51%
943
27%
1714
December16th to endNight
36%
1040
17%
2704
9%
1040
40%
1040
22%
1968

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
11%5%25%5%35%5%6%9%38%
49410
Night
11%5%2442445%8%46%
49028
TransparencyDay
39%8%13%17%13%5%
49110
Night
35%6%13%20%15%8%
48833
SeeingDay
11%213%26%30%15%
5842
Night
13%317%29%28%7%
16024

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
16%5%34434446%41%
1746
16th to endDay
18%7%34423435%42%
1872
February1st to 15thDay
20%6%35%434436%38%
1785
16th to endDay
19%7%26%423336%39%
1807
March1st to 15thDay
20%6%24423435%40%
1980
16th to endDay
12%6%35%42335%7%45%
2110
April1st to 15thDay
12%6%36%5%25%45%8%40%
2040
16th to endDay
11%6%35%425%45%9%41%
2160
May1st to 15thDay
10%6%25%6%35%6%5%9%37%
2160
16th to endDay
8%436%5%45%6%6%12%36%
2430
June1st to 15thDay
6%426%5%46%7%7%12%37%
2340
16th to endDay
7%5%36%6%47%10%9%12%24%
2340
July1st to 15thDay
9%436%5%47%7%9%14%28%
2340
16th to endDay
7%5%26%6%48%8%9%12%27%
2466
August1st to 15thDay
3325%447%7%10%14%35%
2289
16th to endDay
11%5%26%7%46%8%8%10%27%
2292
September1st to 15thDay
9%5%36%5%46%7%8%9%31%
2027
16th to endDay
10%426%6%45%5%6%8%38%
1980
October1st to 15thDay
6%3244345%7%7%50%
1812
16th to endDay
10%313223346%58%
1920
November1st to 15thDay
9%4244445%5%9%44%
1908
16th to endDay
11%5%35%423335%52%
1950
December1st to 15thDay
16%6%25%5%24347%39%
1784
16th to endDay
17%9%35%5%34436%33%
1872
January1st to 15thNight
17%7%24423345%43%
2522
16th to endNight
17%6%25%423345%43%
2704
February1st to 15thNight
17%7%35%423235%42%
2406
16th to endNight
14%8%35%42335%6%42%
1813
March1st to 15thNight
18%6%24423347%42%
1980
16th to endNight
10%5%14424447%51%
2112
April1st to 15thNight
11%5%25%4245%5%7%45%
1908
16th to endNight
12%4244245%6%9%42%
1800
May1st to 15thNight
8%4245%35%5%7%10%41%
1786
16th to endNight
5%313435%6%6%12%46%
1683
June1st to 15thNight
3213325%5%7%13%52%
1620
16th to endNight
7%425%436%6%9%12%37%
1620
July1st to 15thNight
5%324435%5%8%12%43%
1620
16th to endNight
42245%35%6%7%11%45%
1702
August1st to 15thNight
21123235%7%13%56%
1668
16th to endNight
7%426%6%35%5%7%12%38%
1910
September1st to 15thNight
7%424445%5%6%11%42%
1929
16th to endNight
7%425%5%345%6%8%46%
1980
October1st to 15thNight
6%21232435%8%59%
2134
16th to endNight
8%313212235%63%
2304
November1st to 15thNight
8%42432345%8%51%
2280
16th to endNight
10%42432233457%
2340
December1st to 15thNight
16%6%345%3445%6%41%
2503
16th to endNight
21%8%25%5%24346%34%
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
43%5%6%16%19%8%
1747
16th to endDay
44%45%16%17%11%
1872
February1st to 15thDay
48%46%16%15%8%
1786
16th to endDay
47%48%14%16%7%
1807
March1st to 15thDay
45%6%8%14%17%6%
1980
16th to endDay
39%5%11%15%22%5%
2112
April1st to 15thDay
41%6%11%16%15%8%
2040
16th to endDay
40%7%13%18%13%6%
2160
May1st to 15thDay
41%8%14%15%13%6%
2160
16th to endDay
36%10%15%23%12%2
2434
June1st to 15thDay
34%11%17%21%13%1
2340
16th to endDay
42%13%19%17%6%
2340
July1st to 15thDay
38%13%22%20%4
2201
16th to endDay
39%17%21%19%1
2311
August1st to 15thDay
29%13%25%25%5%
2275
16th to endDay
45%14%18%14%5%1
2292
September1st to 15thDay
41%15%15%14%10%2
2027
16th to endDay
40%10%12%18%14%3
1980
October1st to 15thDay
28%7%11%24%16%11%
1812
16th to endDay
27%38%16%28%15%
1920
November1st to 15thDay
33%7%15%18%17%7%
1908
16th to endDay
35%46%15%24%13%
1950
December1st to 15thDay
44%5%10%17%13%7%
1784
16th to endDay
51%5%9%14%13%5%
1872
January1st to 15thNight
43%46%14%21%9%
2522
16th to endNight
42%47%15%16%13%
2704
February1st to 15thNight
45%38%12%20%10%
2416
16th to endNight
42%5%6%16%17%11%
1813
March1st to 15thNight
41%5%10%16%17%9%
1980
16th to endNight
33%5%13%17%21%8%
2112
April1st to 15thNight
36%6%11%19%15%10%
1908
16th to endNight
37%7%13%18%14%8%
1800
May1st to 15thNight
35%8%13%20%12%9%
1787
16th to endNight
27%9%16%28%14%2
1685
June1st to 15thNight
21%10%19%29%18%
1620
16th to endNight
34%9%24%23%8%
1620
July1st to 15thNight
30%10%28%24%5%
1530
16th to endNight
28%11%27%28%2
1594
August1st to 15thNight
17%9%28%37%6%
1658
16th to endNight
36%11%24%20%41
1910
September1st to 15thNight
33%10%22%18%11%3
1929
16th to endNight
33%8%14%19%17%5%
1980
October1st to 15thNight
22%6%10%28%18%13%
2134
16th to endNight
24%38%17%26%20%
2304
November1st to 15thNight
31%5%14%23%18%7%
2280
16th to endNight
31%37%18%25%13%
2340
December1st to 15thNight
43%5%9%18%14%8%
2503
16th to endNight
50%5%8%13%12%9%
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
22%431%34%7%
135
16th to endDay
13%9%40%29%6%
144
February1st to 15thDay
23%8%34%26%7%
135
16th to endDay
11%8%46%30%5%
100
March1st to 15thDay
21%11%46%14%6%
90
16th to endDay
15%8%27%30%16%2
96
April1st to 15thDay
13%5%25%35%20%
159
16th to endDay
16%422%30%22%2
270
May1st to 15thDay
11%5%25%34%20%2
297
16th to endDay
10%219%37%25%4
517
June1st to 15thDay
9%6%34%38%11%
495
16th to endDay
10%6%26%36%19%
495
July1st to 15thDay
7%222%43%23%
475
16th to endDay
7%217%41%30%
515
August1st to 15thDay
5%211%47%32%
442
16th to endDay
15%5%10%34%34%
332
September1st to 15thDay
6%319%42%26%
182
16th to endDay
5%216%47%28%
135
October1st to 15thDay
6%228%43%17%
135
16th to endDay
14%215%27%29%10%
144
November1st to 15thDay
12%16%35%30%4
135
16th to endDay
9%224%43%12%6%
135
December1st to 15thDay
26%217%31%12%8%
135
16th to endDay
25%9%34%26%3
144
January1st to 15thNight
20%6%28%31%12%
975
16th to endNight
19%5%27%36%10%
1040
February1st to 15thNight
21%6%26%35%9%
888
16th to endNight
18%7%32%32%8%
495
March1st to 15thNight
21%5%27%34%11%
540
16th to endNight
12%5%22%37%20%1
576
April1st to 15thNight
12%427%39%14%
539
16th to endNight
15%324%35%19%
540
May1st to 15thNight
10%323%42%18%
540
16th to endNight
5%115%38%33%4
563
June1st to 15thNight
4230%56%7%
540
16th to endNight
7%1420%49%17%
540
July1st to 15thNight
5%214%50%25%
510
16th to endNight
4110%52%30%
564
August1st to 15thNight
31362%29%
539
16th to endNight
9%212%51%23%
573
September1st to 15thNight
8%415%51%20%
540
16th to endNight
9%421%51%12%
537
October1st to 15thNight
6%18%26%46%10%
694
16th to endNight
9%216%32%32%6%
768
November1st to 15thNight
10%215%38%27%5%
760
16th to endNight
12%321%37%22%2
780
December1st to 15thNight
18%6%20%35%17%1
943
16th to endNight
24%7%26%28%12%
1040
Page generated at 2018-02-23 10:21:29. Version ac04

Copyright 2018 A. Danko


Anahuac Wildlife Refuge Clear Sky Chart |Charts Home