New Mexico Astronomy Village
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the New Mexico Astronomy Village 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
64%
15696
35%
48274
26%
15656
74%
15656
50%
23313

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
61%
760
33%
2471
27%
760
72%
760
47%
1183
January16th to endNight
58%
768
38%
2496
30%
768
72%
768
46%
1191
February1st to 15thNight
59%
700
36%
2246
27%
697
74%
697
55%
1000
February16th to endNight
49%
632
43%
1813
24%
632
68%
632
56%
862
March1st to 15thNight
51%
720
41%
1980
21%
720
68%
720
56%
954
March16th to endNight
56%
768
40%
2112
21%
768
71%
768
61%
980
April1st to 15thNight
45%
569
37%
1828
18%
569
68%
569
53%
799
April16th to endNight
43%
540
43%
1800
22%
540
73%
540
60%
700
May1st to 15thNight
50%
539
34%
1796
23%
539
68%
539
60%
728
May16th to endNight
56%
562
36%
1684
24%
561
68%
561
55%
772
June1st to 15thNight
68%
540
32%
1620
26%
540
73%
540
59%
736
June16th to endNight
75%
540
24%
1620
20%
540
79%
540
49%
822
July1st to 15thNight
77%
510
19%
1530
17%
510
77%
510
37%
875
July16th to endNight
74%
564
19%
1593
18%
531
75%
531
31%
987
August1st to 15thNight
77%
539
18%
1683
20%
536
77%
536
29%
1030
August16th to endNight
77%
573
24%
1910
27%
573
79%
573
31%
1118
September1st to 15thNight
77%
540
26%
1800
29%
540
77%
540
33%
1041
September16th to endNight
73%
692
38%
1995
28%
692
79%
692
53%
998
October1st to 15thNight
73%
720
37%
2160
27%
720
79%
720
59%
989
October16th to endNight
77%
768
44%
2304
32%
768
85%
768
68%
970
November1st to 15thNight
74%
760
43%
2280
31%
760
83%
760
65%
973
November16th to endNight
66%
780
45%
2340
34%
780
76%
780
56%
1094
December1st to 15thNight
64%
780
38%
2509
31%
780
74%
780
48%
1204
December16th to endNight
59%
832
37%
2704
31%
832
69%
832
45%
1307

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
4213323346%64%
49049
Night
3212323346%64%
48480
TransparencyDay
20%35%15%27%27%
48745
Night
19%36%16%27%26%
48285
SeeingDay
6%7%19%29%26%11%
5509
Night
4321%39%25%4
15706

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
4212223445%65%
1710
16th to endDay
7%312212345%63%
1728
February1st to 15thDay
2212212226%71%
1606
16th to endDay
3212212346%69%
1658
March1st to 15thDay
321322334468%
1980
16th to endDay
2111113335%73%
2112
April1st to 15thDay
2113212236%72%
2120
16th to endDay
111111125%81%
2160
May1st to 15thDay
11121324475%
2151
16th to endDay
21221223475%
2428
June1st to 15thDay
212213246%71%
2340
16th to endDay
321232446%7%62%
2340
July1st to 15thDay
6%3245%46%6%8%10%43%
2340
16th to endDay
7%415%7%48%7%8%10%33%
2467
August1st to 15thDay
5%3246%35%7%8%10%41%
2268
16th to endDay
6%3145%45%6%6%8%47%
2292
September1st to 15thDay
8%3245%346%6%8%47%
2160
16th to endDay
5%212212246%68%
1960
October1st to 15thDay
222212346%69%
1800
16th to endDay
11211222477%
1920
November1st to 15thDay
122212236%72%
1909
16th to endDay
3312312225%70%
1950
December1st to 15thDay
5%32313345%65%
1778
16th to endDay
4422223337%64%
1872
January1st to 15thNight
5%312223337%63%
2471
16th to endNight
6%312312235%65%
2496
February1st to 15thNight
212213426%70%
2245
16th to endNight
3311213335%70%
1813
March1st to 15thNight
321213445%69%
1980
16th to endNight
221211223376%
2112
April1st to 15thNight
2212212335%71%
1828
16th to endNight
111121223478%
1800
May1st to 15thNight
212112235%75%
1796
16th to endNight
312313325%71%
1684
June1st to 15thNight
312213446%69%
1620
16th to endNight
2212335%5%7%8%58%
1620
July1st to 15thNight
4313436%7%9%12%41%
1620
16th to endNight
3436%5%46%7%9%14%36%
1701
August1st to 15thNight
4424446%8%8%12%37%
1692
16th to endNight
42146%47%7%8%10%41%
1910
September1st to 15thNight
5%425%436%5%7%8%46%
1800
16th to endNight
4213313245%67%
1995
October1st to 15thNight
312212235%71%
2160
16th to endNight
21111223378%
2304
November1st to 15thNight
111212335%75%
2280
16th to endNight
5%2221223471%
2340
December1st to 15thNight
6%23213346%64%
2509
16th to endNight
5%313323345%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
19%3418%34%19%
1711
16th to endDay
23%2314%35%21%
1728
February1st to 15thDay
17%2416%29%31%
1607
16th to endDay
16%2213%36%27%
1658
March1st to 15thDay
19%2211%31%32%
1980
16th to endDay
14%2210%33%37%
2112
April1st to 15thDay
14%219%37%34%
2120
16th to endDay
9%17%28%53%
2160
May1st to 15thDay
11%2310%27%44%
2151
16th to endDay
12%239%25%46%
2431
June1st to 15thDay
13%218%21%52%
2340
16th to endDay
18%4413%19%38%
2340
July1st to 15thDay
30%7%10%19%17%14%
2201
16th to endDay
39%8%15%23%11%2
2312
August1st to 15thDay
32%7%15%21%17%5%
2253
16th to endDay
31%7%11%19%18%11%
2292
September1st to 15thDay
31%410%20%21%11%
2160
16th to endDay
17%2415%35%24%
1960
October1st to 15thDay
16%26%13%26%33%
1800
16th to endDay
12%1218%31%33%
1920
November1st to 15thDay
15%1417%33%27%
1909
16th to endDay
18%2314%35%26%
1950
December1st to 15thDay
21%25%20%33%16%
1778
16th to endDay
21%16%22%32%14%
1872
January1st to 15thNight
22%25%16%34%18%
2471
16th to endNight
22%1218%35%18%
2496
February1st to 15thNight
16%2417%30%29%
2255
16th to endNight
16%2216%35%26%
1813
March1st to 15thNight
16%2315%29%32%
1980
16th to endNight
14%1212%32%36%
2112
April1st to 15thNight
16%1310%35%32%
1828
16th to endNight
11%1110%27%47%
1800
May1st to 15thNight
12%2210%26%45%
1797
16th to endNight
16%238%24%43%
1685
June1st to 15thNight
15%239%21%46%
1620
16th to endNight
20%5%6%15%16%36%
1620
July1st to 15thNight
28%7%16%20%14%12%
1530
16th to endNight
35%6%21%24%9%1
1593
August1st to 15thNight
35%7%17%20%12%5%
1683
16th to endNight
32%7%13%20%16%8%
1910
September1st to 15thNight
32%6%12%21%14%12%
1800
16th to endNight
19%36%16%32%21%
1995
October1st to 15thNight
15%26%14%27%33%
2160
16th to endNight
11%1316%29%37%
2304
November1st to 15thNight
12%1319%34%29%
2280
16th to endNight
18%1213%33%29%
2340
December1st to 15thNight
21%25%20%31%17%
2509
16th to endNight
22%35%22%34%12%
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
13%5%26%32%17%4
123
16th to endDay
5%5%28%30%17%13%
96
February1st to 15thDay
4315%32%36%7%
90
16th to endDay
6%23%28%20%16%5%
159
March1st to 15thDay
7%14%28%26%17%5%
270
16th to endDay
6%20%28%27%12%4
288
April1st to 15thDay
6%20%29%25%15%2
269
16th to endDay
5%19%37%24%11%
270
May1st to 15thDay
317%35%28%13%2
288
16th to endDay
310%31%35%16%2
330
June1st to 15thDay
3424%38%20%8%
315
16th to endDay
3110%41%29%13%
315
July1st to 15thDay
7%330%38%19%
305
16th to endDay
6%2423%34%27%
327
August1st to 15thDay
5%2320%43%25%
315
16th to endDay
6%15%22%38%25%
332
September1st to 15thDay
10%16%29%41%10%
315
16th to endDay
4417%40%27%7%
274
October1st to 15thDay
6%112%25%34%19%
135
16th to endDay
2114%22%36%22%
144
November1st to 15thDay
5%228%33%22%8%
135
16th to endDay
7%8%22%28%26%6%
135
December1st to 15thDay
7%417%33%27%10%
135
16th to endDay
11%6%18%38%20%4
144
January1st to 15thNight
6%324%39%21%4
764
16th to endNight
7%423%42%17%4
768
February1st to 15thNight
35%28%40%19%3
704
16th to endNight
46%36%39%10%1
632
March1st to 15thNight
47%32%37%15%2
720
16th to endNight
36%29%45%13%1
768
April1st to 15thNight
39%37%37%10%1
569
16th to endNight
111%40%35%9%1
540
May1st to 15thNight
35%38%42%8%1
540
16th to endNight
3430%44%15%
563
June1st to 15thNight
3120%50%21%1
540
16th to endNight
2213%48%32%1
540
July1st to 15thNight
5%5%35%47%5%
510
16th to endNight
41327%52%11%
564
August1st to 15thNight
6%126%50%14%
539
16th to endNight
5%324%56%9%
573
September1st to 15thNight
7%336%48%3
540
16th to endNight
6%112%40%32%7%
692
October1st to 15thNight
4116%46%27%4
720
16th to endNight
2116%40%31%7%
768
November1st to 15thNight
2118%40%29%7%
760
16th to endNight
5%318%38%27%5%
780
December1st to 15thNight
6%321%43%21%4
780
16th to endNight
5%424%42%17%4
832
Page generated at 2018-01-12 20:01:33. Version ac04

Copyright 2018 A. Danko


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