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 2017-04-28.

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
49%
15305
29%
45647
16%
15260
61%
15260
39%
24474

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
44%
767
32%
2374
20%
763
60%
763
47%
1132
January16th to endNight
39%
768
33%
2496
19%
768
56%
768
40%
1240
February1st to 15thNight
37%
702
27%
2211
15%
700
52%
700
37%
1167
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
34%
534
32%
1780
15%
534
58%
534
36%
876
May1st to 15thNight
41%
495
26%
1649
17%
494
57%
494
35%
865
May16th to endNight
49%
515
28%
1401
14%
513
62%
513
42%
768
June1st to 15thNight
55%
495
26%
1320
16%
495
63%
495
47%
720
June16th to endNight
66%
495
21%
1320
15%
495
69%
495
43%
743
July1st to 15thNight
75%
465
16%
1285
14%
465
76%
465
30%
825
July16th to endNight
76%
522
12%
1467
12%
489
76%
489
28%
919
August1st to 15thNight
77%
494
14%
1571
15%
491
78%
491
27%
976
August16th to endNight
78%
525
19%
1750
20%
525
80%
525
30%
1043
September1st to 15thNight
68%
495
23%
1650
23%
495
72%
495
27%
1010
September16th to endNight
65%
508
33%
1768
27%
508
74%
508
43%
844
October1st to 15thNight
52%
660
34%
1980
20%
660
63%
660
46%
995
October16th to endNight
57%
704
36%
2112
20%
704
68%
704
52%
1005
November1st to 15thNight
53%
796
37%
2196
19%
796
65%
796
55%
1063
November16th to endNight
48%
900
36%
2340
18%
900
59%
900
49%
1245
December1st to 15thNight
34%
900
28%
2490
11%
900
49%
900
40%
1389
December16th to endNight
32%
960
28%
2688
11%
960
47%
960
36%
1550

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%56%
46045
Night
4413323347%59%
45838
TransparencyDay
25%6%11%20%24%11%
45735
Night
24%5%11%22%25%11%
45649
SeeingDay
8%17%29%30%12%2
4966
Night
6%10%29%33%17%2
15308

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
342322245%67%
1573
16th to endDay
6%6%13311235%63%
1728
February1st to 15thDay
27%35%312246%60%
1650
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%
2127
May1st to 15thDay
4424325%45%7%55%
1971
16th to endDay
33122135%5%7%61%
2355
June1st to 15thDay
22123235%5%6%63%
2310
16th to endDay
2112225%45%7%63%
2310
July1st to 15thDay
5%5%245%47%7%8%10%39%
2258
16th to endDay
5%425%5%48%8%10%10%35%
2285
August1st to 15thDay
5%4146%36%6%8%9%43%
2049
16th to endDay
5%4145%35%7%9%9%42%
2100
September1st to 15thDay
9%5%24436%6%6%7%44%
1980
16th to endDay
421242335%6%63%
1860
October1st to 15thDay
6%213313346%63%
1650
16th to endDay
421321123471%
1760
November1st to 15thDay
2312112338%66%
1651
16th to endDay
5%422213326%66%
1620
December1st to 15thDay
46%23312238%60%
1467
16th to endDay
7%7%33413348%52%
1536
January1st to 15thNight
3413212235%67%
2374
16th to endNight
6%5%13213236%64%
2496
February1st to 15thNight
47%24222236%61%
2201
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%64%
1780
May1st to 15thNight
5%423324446%59%
1649
16th to endNight
331232435%6%63%
1401
June1st to 15thNight
2113424447%62%
1320
16th to endNight
1213325%5%6%8%58%
1320
July1st to 15thNight
42136%37%7%9%10%43%
1369
16th to endNight
4314437%8%9%14%37%
1575
August1st to 15thNight
4313437%6%9%10%43%
1580
16th to endNight
4214437%8%8%10%43%
1750
September1st to 15thNight
6%314436%6%9%10%42%
1650
16th to endNight
5%213223345%63%
1768
October1st to 15thNight
5%312323335%65%
1980
16th to endNight
311322234469%
2112
November1st to 15thNight
3312212326%71%
2196
16th to endNight
5%412213245%67%
2340
December1st to 15thNight
7%7%23212246%59%
2490
16th to endNight
6%7%24313246%56%
2688

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%411%28%32%4
1574
16th to endDay
25%38%24%28%9%
1728
February1st to 15thDay
26%5%11%25%20%11%
1651
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%5%7%20%28%12%
2127
May1st to 15thDay
27%6%10%16%27%11%
1971
16th to endDay
22%5%10%20%24%17%
2358
June1st to 15thDay
19%5%11%15%22%25%
2310
16th to endDay
17%7%10%18%23%21%
2310
July1st to 15thDay
37%10%16%12%11%10%
2113
16th to endDay
35%13%21%22%6%1
2130
August1st to 15thDay
33%11%18%18%12%5%
2034
16th to endDay
33%11%16%21%13%3
2100
September1st to 15thDay
36%9%16%17%13%6%
1980
16th to endDay
20%5%10%20%28%13%
1860
October1st to 15thDay
22%47%20%30%14%
1650
16th to endDay
17%36%20%37%13%
1760
November1st to 15thDay
17%29%22%34%13%
1651
16th to endDay
20%36%22%34%12%
1620
December1st to 15thDay
23%414%29%23%4
1467
16th to endDay
30%5%14%24%20%3
1536
January1st to 15thNight
18%310%29%30%7%
2374
16th to endNight
22%49%24%30%8%
2496
February1st to 15thNight
26%412%24%22%10%
2211
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
22%47%19%31%14%
1780
May1st to 15thNight
25%5%10%17%28%12%
1650
16th to endNight
21%7%10%21%22%16%
1402
June1st to 15thNight
20%6%11%16%18%25%
1320
16th to endNight
23%7%12%15%18%23%
1320
July1st to 15thNight
30%14%19%15%9%11%
1285
16th to endNight
31%13%26%19%7%
1467
August1st to 15thNight
29%15%20%16%11%6%
1571
16th to endNight
28%12%18%23%11%5%
1750
September1st to 15thNight
31%13%18%15%13%7%
1650
16th to endNight
21%5%11%18%27%15%
1768
October1st to 15thNight
21%49%20%29%15%
1980
16th to endNight
17%38%18%37%15%
2112
November1st to 15thNight
16%27%24%36%12%
2196
16th to endNight
21%26%21%33%14%
2340
December1st to 15thNight
26%410%28%23%5%
2490
16th to endNight
29%412%27%22%4
2688

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
15%27%25%21%10%
90
16th to endDay
7%37%28%15%9%2
96
February1st to 15thDay
226%35%32%3
90
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
13%38%33%12%1
259
May1st to 15thDay
7%32%41%17%1
228
16th to endDay
5%13%37%32%9%
420
June1st to 15thDay
5%11%29%34%17%1
420
16th to endDay
2322%35%30%4
420
July1st to 15thDay
8%219%36%26%5%
352
16th to endDay
9%112%42%26%7%
271
August1st to 15thDay
7%318%43%23%3
255
16th to endDay
8%424%45%14%2
268
September1st to 15thDay
9%333%44%7%
255
16th to endDay
7%11%31%39%9%1
153
October1st to 15thDay
5%14%35%28%11%4
90
16th to endDay
12%15%29%23%14%4
96
November1st to 15thDay
11%11%33%30%13%1
90
16th to endDay
13%34%26%18%6%
90
December1st to 15thDay
5%37%33%22%1
90
16th to endDay
16%28%36%16%2
96
January1st to 15thNight
5%11%34%33%13%2
768
16th to endNight
8%13%38%27%11%2
768
February1st to 15thNight
7%12%38%31%8%
704
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
8%17%36%28%7%
534
May1st to 15thNight
5%11%36%33%11%
495
16th to endNight
6%10%31%37%14%
515
June1st to 15thNight
3430%43%17%
495
16th to endNight
2322%42%28%1
495
July1st to 15thNight
48%41%39%4
465
16th to endNight
47%27%50%9%
522
August1st to 15thNight
47%30%45%10%
494
16th to endNight
49%36%41%7%
525
September1st to 15thNight
7%213%41%31%4
495
16th to endNight
5%319%42%25%2
508
October1st to 15thNight
7%6%30%36%16%3
660
16th to endNight
5%6%27%36%20%4
704
November1st to 15thNight
5%9%29%35%18%2
796
16th to endNight
6%12%30%32%14%3
900
December1st to 15thNight
11%13%38%28%7%1
900
16th to endNight
10%14%39%27%7%
960
Page generated at 2017-04-29 07:44:59. Version ac04

Copyright 2017 A. Danko


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