Chiricahua
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Chiricahua clear sky chart from 2005-11-05 to 2017-04-08.

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
65%
14904
34%
45352
26%
14862
74%
14862
46%
22650

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
62%
720
31%
2327
29%
716
69%
716
45%
1131
January16th to endNight
57%
768
35%
2496
29%
768
69%
768
39%
1286
February1st to 15thNight
63%
698
36%
2272
30%
696
75%
696
50%
1030
February16th to endNight
51%
632
42%
1757
27%
632
66%
632
48%
897
March1st to 15thNight
55%
720
39%
1980
24%
720
68%
720
51%
998
March16th to endNight
58%
768
39%
2112
21%
768
73%
768
56%
1014
April1st to 15thNight
49%
602
37%
1812
18%
602
69%
602
48%
866
April16th to endNight
54%
495
41%
1650
26%
495
75%
495
59%
638
May1st to 15thNight
57%
494
37%
1578
24%
494
73%
494
59%
644
May16th to endNight
60%
513
38%
1540
26%
513
71%
513
60%
670
June1st to 15thNight
73%
495
36%
1485
30%
495
77%
495
64%
644
June16th to endNight
75%
495
24%
1485
20%
495
76%
495
45%
766
July1st to 15thNight
76%
465
16%
1395
15%
465
77%
465
29%
871
July16th to endNight
75%
522
13%
1467
12%
489
75%
489
21%
1011
August1st to 15thNight
76%
494
18%
1490
18%
491
76%
491
27%
951
August16th to endNight
76%
525
22%
1750
25%
525
77%
525
28%
1078
September1st to 15thNight
73%
570
24%
1725
23%
570
74%
570
30%
1082
September16th to endNight
77%
656
36%
1815
26%
656
82%
656
55%
912
October1st to 15thNight
72%
660
37%
1972
27%
660
79%
660
56%
928
October16th to endNight
78%
704
41%
2112
32%
704
85%
704
65%
912
November1st to 15thNight
71%
700
42%
2100
32%
700
79%
700
63%
902
November16th to endNight
63%
720
40%
2196
32%
720
72%
720
49%
1045
December1st to 15thNight
64%
720
37%
2340
32%
720
72%
720
45%
1121
December16th to endNight
58%
768
34%
2496
31%
768
66%
768
40%
1253

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
321342445%7%59%
45890
Night
221332445%7%62%
45559
TransparencyDay
24%36%13%27%24%
45585
Night
21%37%14%28%24%
45365
SeeingDay
6%13%23%31%20%4
4637
Night
46%18%34%29%6%
14913

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
131342446%7%59%
1611
16th to endDay
433441445%6%56%
1728
February1st to 15thDay
2213423346%66%
1578
16th to endDay
1313325%45%5%63%
1714
March1st to 15thDay
1213323446%65%
1980
16th to endDay
2212312335%70%
2112
April1st to 15thDay
121221335%6%69%
1975
16th to endDay
11121122478%
1980
May1st to 15thDay
12323345%71%
2040
16th to endDay
211213335%74%
2221
June1st to 15thDay
1112212345%73%
2145
16th to endDay
2213325%5%6%7%58%
2145
July1st to 15thDay
5%326%6%47%7%8%11%36%
2145
16th to endDay
7%437%8%5%8%8%8%11%26%
2285
August1st to 15thDay
5%5%37%8%46%7%8%11%30%
2129
16th to endDay
6%426%6%5%7%8%8%8%35%
2100
September1st to 15thDay
7%316%6%36%7%7%8%39%
1901
16th to endDay
5%2133135%5%6%61%
1815
October1st to 15thDay
1113423246%69%
1658
16th to endDay
1112213236%73%
1760
November1st to 15thDay
12212247%72%
1759
16th to endDay
223423335%68%
1761
December1st to 15thDay
321232345%8%62%
1620
16th to endDay
231342445%7%60%
1728
January1st to 15thNight
231342345%6%62%
2327
16th to endNight
3315%4235%5%6%59%
2496
February1st to 15thNight
111332345%7%66%
2272
16th to endNight
11232445%6%65%
1757
March1st to 15thNight
13332245%6%66%
1980
16th to endNight
21221333472%
2112
April1st to 15thNight
1223323345%67%
1812
16th to endNight
111223479%
1650
May1st to 15thNight
12212347%72%
1578
16th to endNight
11221224476%
1540
June1st to 15thNight
3112111335%73%
1485
16th to endNight
22224345%7%6%59%
1485
July1st to 15thNight
24245%48%8%9%12%36%
1485
16th to endNight
5%325%6%5%9%10%10%13%25%
1575
August1st to 15thNight
44346%48%7%9%11%36%
1499
16th to endNight
44146%5%6%5%7%12%40%
1750
September1st to 15thNight
6%315%5%46%6%7%10%41%
1725
16th to endNight
322312346%68%
1815
October1st to 15thNight
1212213345%71%
1972
16th to endNight
111212245%76%
2112
November1st to 15thNight
11222246%74%
2100
16th to endNight
3212223345%69%
2196
December1st to 15thNight
32122245%5%6%62%
2340
16th to endNight
13134245%46%61%
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
24%36%13%33%19%
1612
16th to endDay
29%2414%28%19%
1728
February1st to 15thDay
21%214%31%28%
1578
16th to endDay
23%2414%31%24%
1714
March1st to 15thDay
20%2210%37%27%
1980
16th to endDay
17%1211%36%29%
2112
April1st to 15thDay
16%138%39%29%
1975
16th to endDay
12%118%31%44%
1980
May1st to 15thDay
15%238%27%41%
2040
16th to endDay
14%238%30%41%
2224
June1st to 15thDay
14%235%24%50%
2145
16th to endDay
23%5%6%9%21%33%
2145
July1st to 15thDay
37%9%15%16%12%8%
2006
16th to endDay
48%9%18%15%6%
2130
August1st to 15thDay
44%9%14%17%11%2
2114
16th to endDay
42%9%12%14%13%7%
2100
September1st to 15thDay
40%6%10%18%16%7%
1901
16th to endDay
24%35%15%32%18%
1815
October1st to 15thDay
17%35%15%29%28%
1658
16th to endDay
16%1413%32%31%
1760
November1st to 15thDay
13%1316%36%27%
1759
16th to endDay
19%1314%32%27%
1761
December1st to 15thDay
22%16%18%34%17%
1620
16th to endDay
25%27%21%31%12%
1728
January1st to 15thNight
22%36%14%31%22%
2327
16th to endNight
27%2317%31%17%
2496
February1st to 15thNight
18%2416%31%27%
2283
16th to endNight
21%1313%34%24%
1757
March1st to 15thNight
19%2312%33%28%
1980
16th to endNight
16%1310%39%28%
2112
April1st to 15thNight
19%2312%38%24%
1812
16th to endNight
10%129%33%42%
1650
May1st to 15thNight
11%248%33%38%
1579
16th to endNight
13%2312%31%36%
1541
June1st to 15thNight
13%135%25%50%
1485
16th to endNight
22%4410%22%34%
1485
July1st to 15thNight
33%10%19%18%10%8%
1395
16th to endNight
41%12%23%17%41
1467
August1st to 15thNight
36%10%17%16%15%3
1490
16th to endNight
34%9%15%16%14%8%
1750
September1st to 15thNight
35%7%13%19%16%7%
1725
16th to endNight
18%36%16%37%17%
1815
October1st to 15thNight
15%38%16%27%27%
1972
16th to endNight
12%1414%29%36%
2112
November1st to 15thNight
11%25%17%35%27%
2100
16th to endNight
20%1412%29%31%
2196
December1st to 15thNight
22%26%19%31%18%
2340
16th to endNight
25%28%19%30%14%
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
6%14%33%35%10%
90
16th to endDay
5%15%27%30%17%4
96
February1st to 15thDay
5%9%15%39%26%3
93
16th to endDay
6%31%31%21%7%1
238
March1st to 15thDay
7%20%33%22%11%3
270
16th to endDay
5%27%28%24%11%3
288
April1st to 15thDay
5%25%33%25%6%2
239
16th to endDay
431%34%21%5%1
210
May1st to 15thDay
428%39%21%6%
228
16th to endDay
415%39%29%9%
266
June1st to 15thDay
37%36%34%14%3
255
16th to endDay
5%120%45%25%1
255
July1st to 15thDay
9%11%46%31%
245
16th to endDay
417%39%33%12%
271
August1st to 15thDay
6%7%31%41%12%
255
16th to endDay
7%6%32%43%9%
268
September1st to 15thDay
11%114%36%30%5%
255
16th to endDay
9%7%17%37%23%4
255
October1st to 15thDay
28%21%28%30%9%
98
16th to endDay
4418%30%37%5%
96
November1st to 15thDay
121%25%28%21%2
90
16th to endDay
6%26%18%33%14%
90
December1st to 15thDay
412%20%28%32%2
90
16th to endDay
15%19%27%30%6%1
96
January1st to 15thNight
4422%38%22%5%
720
16th to endNight
6%9%20%35%23%4
768
February1st to 15thNight
210%19%35%26%5%
704
16th to endNight
213%30%37%13%2
632
March1st to 15thNight
5%10%25%34%20%4
720
16th to endNight
310%23%34%24%4
768
April1st to 15thNight
212%30%36%15%1
602
16th to endNight
113%30%35%16%3
495
May1st to 15thNight
19%28%38%18%2
495
16th to endNight
16%26%37%25%2
515
June1st to 15thNight
3216%48%26%2
495
16th to endNight
3111%43%36%3
495
July1st to 15thNight
46%32%46%9%
465
16th to endNight
6%424%51%12%
522
August1st to 15thNight
6%318%53%18%
494
16th to endNight
6%321%54%14%
525
September1st to 15thNight
7%15%23%48%13%
570
16th to endNight
4110%32%41%8%
656
October1st to 15thNight
2318%36%29%8%
660
16th to endNight
2213%35%34%11%
704
November1st to 15thNight
15%18%34%31%8%
700
16th to endNight
5%9%18%30%27%8%
720
December1st to 15thNight
6%9%16%34%27%6%
720
16th to endNight
411%19%38%19%5%
768
Page generated at 2017-04-09 03:54:10. Version ac04

Copyright 2017 A. Danko


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