Santa Fe
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Santa Fe clear sky chart from 2005-11-05 to 2018-02-14.

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
50%
16372
29%
48824
17%
16327
61%
16327
40%
26066

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
45%
831
32%
2573
20%
827
60%
827
47%
1230
January16th to endNight
41%
832
34%
2704
21%
832
59%
832
42%
1317
February1st to 15thNight
37%
758
27%
2387
15%
756
52%
756
38%
1246
February16th to endNight
28%
632
35%
1894
13%
632
50%
632
39%
996
March1st to 15thNight
42%
720
32%
2049
16%
720
56%
720
39%
1108
March16th to endNight
38%
714
33%
2058
15%
714
54%
714
44%
1069
April1st to 15thNight
32%
539
29%
1798
12%
539
53%
539
32%
926
April16th to endNight
33%
540
32%
1800
15%
540
57%
540
35%
894
May1st to 15thNight
41%
540
25%
1799
16%
539
56%
539
35%
941
May16th to endNight
49%
563
30%
1532
15%
561
62%
561
43%
834
June1st to 15thNight
57%
540
25%
1440
15%
540
64%
540
47%
786
June16th to endNight
68%
540
24%
1440
18%
540
71%
540
45%
801
July1st to 15thNight
75%
510
16%
1410
14%
510
76%
510
31%
895
July16th to endNight
76%
564
13%
1593
13%
531
76%
531
28%
992
August1st to 15thNight
77%
539
13%
1715
15%
536
77%
536
27%
1075
August16th to endNight
77%
573
21%
1910
22%
573
79%
573
30%
1130
September1st to 15thNight
70%
540
22%
1800
22%
540
74%
540
28%
1087
September16th to endNight
63%
555
34%
1929
28%
555
72%
555
41%
940
October1st to 15thNight
52%
720
33%
2160
20%
720
63%
720
47%
1084
October16th to endNight
58%
768
38%
2304
21%
768
69%
768
53%
1088
November1st to 15thNight
52%
864
36%
2384
18%
864
63%
864
54%
1157
November16th to endNight
49%
975
38%
2535
19%
975
60%
975
51%
1333
December1st to 15thNight
37%
975
29%
2698
12%
975
50%
975
41%
1486
December16th to endNight
34%
1040
30%
2912
12%
1040
49%
1040
37%
1651

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
442332445%7%57%
49248
Night
441332345%7%59%
49015
TransparencyDay
25%6%11%21%24%11%
48938
Night
23%5%11%22%25%11%
48826
SeeingDay
7%16%28%30%13%2
6035
Night
6%9%29%33%17%2
16375

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
342323346%66%
1705
16th to endDay
6%6%13211235%65%
1872
February1st to 15thDay
27%35%312246%61%
1774
16th to endDay
38%1431335%8%56%
1580
March1st to 15thDay
46%24323447%56%
1909
16th to endDay
4423324337%59%
2166
April1st to 15thDay
443332445%6%56%
2150
16th to endDay
46%2232335%6%59%
2160
May1st to 15thDay
4323325%46%7%56%
2151
16th to endDay
33122135%5%7%62%
2575
June1st to 15thDay
22122235%5%6%64%
2520
16th to endDay
2112225%45%7%64%
2520
July1st to 15thDay
45%24447%7%8%10%40%
2463
16th to endDay
5%425%5%48%8%10%10%34%
2467
August1st to 15thDay
5%4146%36%6%8%9%43%
2235
16th to endDay
5%4145%35%7%8%9%42%
2292
September1st to 15thDay
8%5%24435%6%6%7%45%
2160
16th to endDay
4212423346%62%
2029
October1st to 15thDay
6%213312336%64%
1800
16th to endDay
321321123472%
1920
November1st to 15thDay
2313112348%66%
1792
16th to endDay
4312212226%67%
1755
December1st to 15thDay
46%23312237%61%
1589
16th to endDay
6%7%23413349%54%
1664
January1st to 15thNight
3413212236%67%
2573
16th to endNight
5%5%13212225%65%
2704
February1st to 15thNight
47%24222235%62%
2377
16th to endNight
5%7%23312236%61%
1894
March1st to 15thNight
46%23223346%59%
2049
16th to endNight
5%5%22212335%65%
2058
April1st to 15thNight
5%42432345%6%57%
1798
16th to endNight
6%5%12312345%63%
1800
May1st to 15thNight
5%423324446%59%
1799
16th to endNight
431322335%6%63%
1532
June1st to 15thNight
2113424447%62%
1440
16th to endNight
1213325%5%6%8%60%
1440
July1st to 15thNight
32136%47%7%9%10%43%
1494
16th to endNight
43145%37%8%10%13%38%
1701
August1st to 15thNight
43145%37%7%9%10%42%
1724
16th to endNight
4214437%8%8%10%43%
1910
September1st to 15thNight
6%314436%6%9%10%42%
1800
16th to endNight
6%213223346%62%
1929
October1st to 15thNight
5%312323235%66%
2160
16th to endNight
311322234470%
2304
November1st to 15thNight
3212212326%71%
2384
16th to endNight
5%412212245%68%
2535
December1st to 15thNight
7%6%23212246%60%
2698
16th to endNight
6%7%24313246%58%
2912

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
18%411%28%31%4
1706
16th to endDay
23%37%25%29%9%
1872
February1st to 15thDay
25%411%25%21%10%
1775
16th to endDay
24%49%22%29%9%
1580
March1st to 15thDay
26%310%21%27%10%
1909
16th to endDay
24%39%21%32%9%
2166
April1st to 15thDay
27%47%23%26%10%
2150
16th to endDay
25%47%20%28%12%
2160
May1st to 15thDay
26%6%10%17%27%11%
2151
16th to endDay
21%5%10%20%25%16%
2578
June1st to 15thDay
19%5%11%15%21%26%
2520
16th to endDay
16%7%10%19%23%22%
2520
July1st to 15thDay
36%11%16%12%13%9%
2318
16th to endDay
36%13%21%21%6%1
2312
August1st to 15thDay
33%12%18%18%12%4
2220
16th to endDay
33%11%15%21%14%3
2292
September1st to 15thDay
34%9%16%18%14%6%
2160
16th to endDay
22%5%9%19%28%14%
2029
October1st to 15thDay
21%47%19%31%16%
1800
16th to endDay
16%37%20%37%13%
1920
November1st to 15thDay
17%39%23%34%12%
1792
16th to endDay
19%36%23%34%13%
1755
December1st to 15thDay
23%414%28%23%6%
1589
16th to endDay
28%5%13%23%23%4
1664
January1st to 15thNight
18%410%29%30%7%
2573
16th to endNight
21%49%23%31%9%
2704
February1st to 15thNight
25%412%26%21%10%
2387
16th to endNight
25%27%22%29%11%
1894
March1st to 15thNight
24%48%26%27%8%
2049
16th to endNight
22%35%22%33%11%
2058
April1st to 15thNight
25%48%24%25%10%
1798
16th to endNight
23%47%19%30%13%
1800
May1st to 15thNight
25%5%10%18%28%11%
1800
16th to endNight
21%6%10%21%22%16%
1533
June1st to 15thNight
20%6%12%15%18%25%
1440
16th to endNight
22%7%11%16%18%23%
1440
July1st to 15thNight
29%13%18%16%10%11%
1410
16th to endNight
30%13%27%19%7%
1593
August1st to 15thNight
30%15%20%17%10%6%
1715
16th to endNight
29%11%17%24%11%4
1910
September1st to 15thNight
30%12%19%17%13%7%
1800
16th to endNight
22%5%11%17%28%14%
1929
October1st to 15thNight
20%48%19%29%17%
2160
16th to endNight
17%38%18%37%15%
2304
November1st to 15thNight
16%38%24%36%11%
2384
16th to endNight
20%26%22%32%15%
2535
December1st to 15thNight
24%410%28%23%7%
2698
16th to endNight
28%411%26%24%4
2912

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%26%28%7%
135
16th to endDay
431%28%22%11%1
144
February1st to 15thDay
228%36%30%2
130
16th to endDay
6%39%28%18%6%1
81
March1st to 15thDay
8%27%35%24%5%
199
16th to endDay
10%36%32%17%2
288
April1st to 15thDay
12%35%32%16%2
269
16th to endDay
14%38%33%11%1
270
May1st to 15thDay
7%29%41%18%2
288
16th to endDay
5%15%38%31%9%
498
June1st to 15thDay
411%28%33%19%1
495
16th to endDay
2324%37%28%4
495
July1st to 15thDay
8%218%36%28%6%
422
16th to endDay
9%111%39%29%8%
327
August1st to 15thDay
7%219%43%22%3
315
16th to endDay
10%321%43%18%3
332
September1st to 15thDay
8%329%44%12%2
315
16th to endDay
11%12%33%32%7%1
204
October1st to 15thDay
7%17%34%26%11%2
135
16th to endDay
8%12%31%29%12%4
144
November1st to 15thDay
8%20%35%25%9%
135
16th to endDay
9%29%29%22%8%
135
December1st to 15thDay
331%34%23%6%
135
16th to endDay
11%28%36%20%3
144
January1st to 15thNight
411%34%34%12%2
832
16th to endNight
7%12%36%29%11%2
832
February1st to 15thNight
7%13%38%31%8%
760
16th to endNight
9%15%43%26%3
632
March1st to 15thNight
6%17%29%36%9%
720
16th to endNight
6%14%37%31%9%
714
April1st to 15thNight
6%20%39%26%6%
539
16th to endNight
9%17%37%28%7%
540
May1st to 15thNight
5%11%37%33%11%
540
16th to endNight
6%10%31%36%14%
563
June1st to 15thNight
3429%42%19%
540
16th to endNight
2222%43%28%1
540
July1st to 15thNight
48%41%40%4
510
16th to endNight
47%26%52%9%
564
August1st to 15thNight
47%32%44%9%
539
16th to endNight
49%35%42%7%
573
September1st to 15thNight
6%212%41%33%4
540
16th to endNight
7%320%41%23%2
555
October1st to 15thNight
7%5%30%37%15%3
720
16th to endNight
46%27%36%19%4
768
November1st to 15thNight
5%9%29%35%17%2
864
16th to endNight
6%11%30%33%14%3
975
December1st to 15thNight
10%12%37%29%8%1
975
16th to endNight
9%14%39%28%7%
1040
Page generated at 2018-02-15 08:58:51. Version ac04

Copyright 2018 A. Danko


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