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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 2017-08-12.

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
67%
15223
34%
46702
26%
15183
76%
15183
49%
22823

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
66%
716
33%
2327
30%
716
75%
716
47%
1131
January16th to endNight
64%
768
37%
2496
30%
768
75%
768
46%
1197
February1st to 15thNight
62%
699
36%
2180
26%
697
75%
697
54%
997
February16th to endNight
51%
632
40%
1882
25%
632
67%
632
53%
905
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%
527
21%
1713
24%
524
80%
524
31%
1015
August16th to endNight
83%
525
24%
1750
28%
525
83%
525
34%
990
September1st to 15thNight
76%
495
25%
1650
29%
495
77%
495
31%
961
September16th to endNight
79%
550
36%
1785
32%
550
84%
550
49%
843
October1st to 15thNight
74%
660
36%
1980
29%
660
77%
660
54%
951
October16th to endNight
79%
704
41%
2112
29%
704
86%
704
65%
914
November1st to 15thNight
74%
700
42%
2100
31%
700
81%
700
66%
893
November16th to endNight
67%
789
40%
2229
29%
789
74%
789
53%
1105
December1st to 15thNight
66%
882
37%
2397
26%
882
73%
882
54%
1237
December16th to endNight
62%
768
37%
2496
31%
768
71%
768
47%
1188

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%
47252
Night
321332345%7%63%
46903
TransparencyDay
18%37%15%27%27%
46948
Night
19%47%15%26%26%
46709
SeeingDay
5%7%18%27%27%14%
4896
Night
4319%41%27%3
15233

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
2413213347%63%
1611
16th to endDay
5%31331235%7%61%
1728
February1st to 15thDay
121221234471%
1676
16th to endDay
1112323225%71%
1589
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%313435%6%8%11%45%
2152
16th to endDay
32145%46%6%8%9%46%
2100
September1st to 15thDay
7%4144345%6%9%48%
1980
16th to endDay
422212347%68%
1843
October1st to 15thDay
3212212246%68%
1650
16th to endDay
22111132477%
1760
November1st to 15thDay
112213236%73%
1759
16th to endDay
5%31212345%69%
1714
December1st to 15thDay
4212213246%66%
1566
16th to endDay
3333313446%62%
1728
January1st to 15thNight
3323223345%64%
2327
16th to endNight
5%312223345%64%
2496
February1st to 15thNight
222223346%67%
2174
16th to endNight
2312313236%67%
1882
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
42146%47%7%9%14%37%
1722
16th to endNight
32135%45%7%9%13%42%
1750
September1st to 15thNight
6%424435%6%7%10%45%
1650
16th to endNight
332223447%64%
1785
October1st to 15thNight
321221235%6%67%
1980
16th to endNight
21111233377%
2112
November1st to 15thNight
1211211236%75%
2100
16th to endNight
431331323469%
2229
December1st to 15thNight
5%312312236%66%
2397
16th to endNight
331331245%5%64%
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
20%3418%34%17%
1612
16th to endDay
21%4415%36%17%
1728
February1st to 15thDay
16%2415%29%31%
1677
16th to endDay
16%1313%35%29%
1589
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%14%24%19%4
2137
16th to endDay
29%7%14%19%21%7%
2100
September1st to 15thDay
30%5%10%21%21%9%
1980
16th to endDay
16%27%18%32%22%
1843
October1st to 15thDay
17%26%13%28%31%
1650
16th to endDay
12%1317%32%33%
1760
November1st to 15thDay
13%25%16%33%28%
1759
16th to endDay
17%2315%34%26%
1714
December1st to 15thDay
19%26%23%33%14%
1566
16th to endDay
22%37%25%32%9%
1728
January1st to 15thNight
22%26%15%32%19%
2327
16th to endNight
21%3316%35%19%
2496
February1st to 15thNight
17%25%15%25%33%
2184
16th to endNight
18%1312%33%29%
1882
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%21%15%4
1713
16th to endNight
27%9%13%25%17%6%
1750
September1st to 15thNight
31%8%14%18%16%11%
1650
16th to endNight
19%37%19%29%21%
1785
October1st to 15thNight
18%36%14%23%34%
1980
16th to endNight
12%2315%26%39%
2112
November1st to 15thNight
11%25%15%34%31%
2100
16th to endNight
19%2311%31%30%
2229
December1st to 15thNight
20%26%20%31%19%
2397
16th to endNight
20%36%22%36%10%
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
12%25%43%14%4
90
16th to endDay
3423%36%19%12%
96
February1st to 15thDay
7%5%8%31%33%13%
90
16th to endDay
312%16%31%26%10%
90
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
3414%42%35%
300
16th to endDay
6%425%39%24%
268
September1st to 15thDay
7%17%27%40%14%
255
16th to endDay
7%110%26%42%10%
178
October1st to 15thDay
7%8%28%33%21%
90
16th to endDay
6%5%27%39%21%
96
November1st to 15thDay
16%20%23%36%12%
90
16th to endDay
14%11%16%31%23%3
90
December1st to 15thDay
6%5%11%34%32%10%
90
16th to endDay
9%430%46%8%1
96
January1st to 15thNight
4121%48%20%3
720
16th to endNight
7%419%47%19%2
768
February1st to 15thNight
3327%41%22%2
704
16th to endNight
46%34%43%10%
632
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%
527
16th to endNight
4423%59%8%
525
September1st to 15thNight
6%5%37%46%4
495
16th to endNight
6%18%42%36%4
550
October1st to 15thNight
5%114%46%29%3
660
16th to endNight
2113%40%34%7%
704
November1st to 15thNight
3118%40%32%4
700
16th to endNight
6%317%40%27%4
789
December1st to 15thNight
6%418%45%23%1
882
16th to endNight
6%320%51%15%1
768
Page generated at 2017-08-13 12:16:37. Version ac04

Copyright 2017 A. Danko


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