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Las Cruces
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Las Cruces 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
68%
15977
34%
49031
27%
15937
76%
15937
49%
23938

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
67%
776
34%
2522
31%
776
75%
776
47%
1220
January16th to endNight
65%
832
37%
2704
31%
832
77%
832
48%
1274
February1st to 15thNight
64%
759
36%
2366
27%
757
76%
757
54%
1084
February16th to endNight
50%
660
40%
1966
25%
660
66%
660
52%
958
March1st to 15thNight
58%
720
37%
1980
23%
720
69%
720
52%
992
March16th to endNight
58%
753
38%
2097
21%
753
72%
753
56%
1006
April1st to 15thNight
46%
539
36%
1798
19%
539
68%
539
48%
791
April16th to endNight
51%
540
42%
1800
28%
540
74%
540
59%
714
May1st to 15thNight
53%
539
32%
1799
24%
539
68%
539
55%
762
May16th to endNight
63%
563
32%
1768
26%
561
74%
561
51%
830
June1st to 15thNight
74%
540
29%
1620
25%
540
78%
540
56%
758
June16th to endNight
78%
540
24%
1620
21%
540
81%
540
48%
819
July1st to 15thNight
81%
510
22%
1530
20%
510
82%
510
40%
863
July16th to endNight
78%
564
24%
1593
24%
531
79%
531
33%
961
August1st to 15thNight
80%
539
20%
1752
23%
536
80%
536
30%
1045
August16th to endNight
83%
573
25%
1910
30%
573
83%
573
35%
1069
September1st to 15thNight
78%
540
25%
1800
28%
540
78%
540
33%
1020
September16th to endNight
78%
600
38%
1947
34%
600
83%
600
48%
929
October1st to 15thNight
75%
720
34%
2160
27%
720
78%
720
54%
1032
October16th to endNight
79%
768
42%
2304
30%
768
86%
768
65%
1000
November1st to 15thNight
75%
760
41%
2280
31%
760
82%
760
66%
973
November16th to endNight
69%
855
42%
2415
31%
855
76%
855
54%
1184
December1st to 15thNight
66%
955
36%
2596
25%
955
72%
955
51%
1362
December16th to endNight
64%
832
38%
2704
32%
832
72%
832
47%
1292

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
321232335%7%64%
49200
Night
321332345%7%63%
49232
TransparencyDay
18%36%16%27%26%
48896
Night
19%47%15%26%26%
49038
SeeingDay
46%17%27%28%14%
5521
Night
4318%41%28%3
15987

By Month

Percentage Cloud Cover SW (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
241322335%7%62%
1746
16th to endDay
5%21331235%7%63%
1872
February1st to 15thDay
2212212345%70%
1820
16th to endDay
2112323225%69%
1651
March1st to 15thDay
2213323445%65%
1980
16th to endDay
2212212235%73%
2126
April1st to 15thDay
222212246%71%
2150
16th to endDay
11111113481%
2160
May1st to 15thDay
111112446%73%
2151
16th to endDay
111112235%77%
2342
June1st to 15thDay
111212235%76%
2340
16th to endDay
211222445%8%64%
2340
July1st to 15thDay
33145%35%6%8%10%46%
2340
16th to endDay
4315%5%46%6%7%11%41%
2467
August1st to 15thDay
5%313426%6%8%11%45%
2199
16th to endDay
32135%46%6%8%9%48%
2292
September1st to 15thDay
6%4143345%6%8%50%
2160
16th to endDay
422212347%68%
2010
October1st to 15thDay
3212212246%69%
1800
16th to endDay
12111132478%
1920
November1st to 15thDay
113213236%71%
1909
16th to endDay
421212246%69%
1857
December1st to 15thDay
5%312213346%64%
1696
16th to endDay
3323313346%62%
1872
January1st to 15thNight
3323223345%64%
2522
16th to endNight
5%312223345%66%
2704
February1st to 15thNight
222223346%68%
2360
16th to endNight
3312313336%66%
1966
March1st to 15thNight
3312223446%65%
1980
16th to endNight
2213213335%70%
2097
April1st to 15thNight
2212323447%66%
1798
16th to endNight
11121224476%
1800
May1st to 15thNight
223223346%70%
1799
16th to endNight
211221435%469%
1768
June1st to 15thNight
112324448%65%
1620
16th to endNight
1113325%6%8%11%54%
1620
July1st to 15thNight
2214427%7%8%13%44%
1620
16th to endNight
3225%5%36%8%7%13%39%
1701
August1st to 15thNight
32146%47%7%9%14%36%
1761
16th to endNight
32135%45%7%8%13%44%
1910
September1st to 15thNight
5%424435%5%7%9%47%
1800
16th to endNight
4312323447%63%
1947
October1st to 15thNight
221232235%6%67%
2160
16th to endNight
21111223377%
2304
November1st to 15thNight
121111237%74%
2280
16th to endNight
421231323469%
2415
December1st to 15thNight
5%313313236%65%
2596
16th to endNight
3313312445%64%
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
21%35%19%34%16%
1747
16th to endDay
20%3414%37%18%
1872
February1st to 15thDay
16%2415%30%30%
1821
16th to endDay
18%1313%34%28%
1651
March1st to 15thDay
19%3411%30%31%
1980
16th to endDay
14%1310%31%38%
2126
April1st to 15thDay
14%239%32%37%
2150
16th to endDay
8%127%26%53%
2160
May1st to 15thDay
10%25%9%26%45%
2151
16th to endDay
10%2410%23%48%
2345
June1st to 15thDay
10%1410%25%48%
2340
16th to endDay
16%47%12%21%36%
2340
July1st to 15thDay
26%8%12%21%17%13%
2201
16th to endDay
31%8%17%23%15%3
2312
August1st to 15thDay
27%8%15%24%19%4
2184
16th to endDay
28%6%14%19%21%8%
2292
September1st to 15thDay
29%5%10%20%21%11%
2160
16th to endDay
16%37%18%32%21%
2010
October1st to 15thDay
17%26%13%29%31%
1800
16th to endDay
11%1318%31%33%
1920
November1st to 15thDay
14%25%19%32%26%
1909
16th to endDay
16%2315%36%25%
1857
December1st to 15thDay
21%26%23%32%13%
1696
16th to endDay
22%36%24%31%10%
1872
January1st to 15thNight
22%36%16%33%18%
2522
16th to endNight
20%3415%35%20%
2704
February1st to 15thNight
17%25%15%25%34%
2370
16th to endNight
19%2312%32%28%
1966
March1st to 15thNight
18%25%13%29%30%
1980
16th to endNight
16%239%29%37%
2097
April1st to 15thNight
16%35%9%30%34%
1798
16th to endNight
11%239%24%49%
1800
May1st to 15thNight
14%2310%23%44%
1800
16th to endNight
17%35%9%21%41%
1770
June1st to 15thNight
16%35%10%17%45%
1620
16th to endNight
20%5%10%15%18%30%
1620
July1st to 15thNight
25%8%12%23%17%12%
1530
16th to endNight
30%9%17%26%12%3
1593
August1st to 15thNight
32%8%18%20%14%4
1752
16th to endNight
27%8%13%24%17%7%
1910
September1st to 15thNight
29%7%13%18%17%13%
1800
16th to endNight
20%36%18%28%21%
1947
October1st to 15thNight
17%36%14%22%34%
2160
16th to endNight
12%2415%27%38%
2304
November1st to 15thNight
11%25%17%33%29%
2280
16th to endNight
19%2311%32%30%
2415
December1st to 15thNight
21%25%19%31%18%
2596
16th to endNight
20%36%21%35%11%
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
10%22%41%16%8%
135
16th to endDay
2418%34%27%13%
144
February1st to 15thDay
8%310%31%31%15%
135
16th to endDay
7%11%19%31%22%8%
109
March1st to 15thDay
5%14%28%28%17%4
270
16th to endDay
6%19%29%24%15%5%
288
April1st to 15thDay
5%18%32%25%15%1
269
16th to endDay
5%21%35%22%11%2
270
May1st to 15thDay
219%34%28%13%2
288
16th to endDay
28%32%36%16%3
330
June1st to 15thDay
45%18%30%26%15%
315
16th to endDay
1112%25%38%21%
315
July1st to 15thDay
25%24%41%24%
305
16th to endDay
4318%35%36%
327
August1st to 15thDay
3413%42%35%
315
16th to endDay
6%320%37%31%
332
September1st to 15thDay
6%7%24%40%19%
315
16th to endDay
6%112%32%38%8%
231
October1st to 15thDay
5%12%25%37%19%
135
16th to endDay
46%24%38%25%
144
November1st to 15thDay
1419%29%36%8%
135
16th to endDay
9%7%14%28%33%6%
135
December1st to 15thDay
8%49%35%32%8%
135
16th to endDay
7%225%43%18%2
144
January1st to 15thNight
4120%48%20%3
780
16th to endNight
7%318%46%21%2
832
February1st to 15thNight
3326%42%22%2
764
16th to endNight
5%6%34%42%10%
660
March1st to 15thNight
5%6%25%44%16%1
720
16th to endNight
36%26%45%16%1
753
April1st to 15thNight
49%36%37%11%1
539
16th to endNight
29%33%39%13%1
540
May1st to 15thNight
35%35%45%10%
540
16th to endNight
3426%47%16%1
563
June1st to 15thNight
2117%50%27%
540
16th to endNight
1111%48%36%1
540
July1st to 15thNight
35%35%50%4
510
16th to endNight
3326%56%9%
564
August1st to 15thNight
41221%58%11%
539
16th to endNight
3422%60%9%
573
September1st to 15thNight
5%437%46%4
540
16th to endNight
7%18%43%35%4
600
October1st to 15thNight
4113%46%30%2
720
16th to endNight
2113%39%36%6%
768
November1st to 15thNight
316%43%32%3
760
16th to endNight
6%316%41%28%4
855
December1st to 15thNight
7%417%45%23%1
955
16th to endNight
6%319%51%17%1
832
Page generated at 2018-02-23 09:21:34. Version ac04

Copyright 2018 A. Danko


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