Homolovi Ruins State
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Homolovi Ruins State clear sky chart from 2005-11-05 to 2017-09-24.

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
70%
15507
33%
46979
28%
15467
76%
15467
51%
22653

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
69%
720
31%
2327
32%
716
73%
716
46%
1132
January16th to endNight
67%
768
35%
2496
34%
768
73%
768
46%
1212
February1st to 15thNight
70%
698
32%
2270
30%
698
77%
698
52%
1038
February16th to endNight
59%
632
39%
1847
31%
632
70%
632
51%
902
March1st to 15thNight
63%
720
37%
1980
27%
720
72%
720
56%
969
March16th to endNight
64%
768
37%
2112
24%
768
73%
768
59%
1010
April1st to 15thNight
51%
650
32%
1909
17%
650
65%
650
52%
906
April16th to endNight
54%
540
39%
1743
25%
540
70%
540
58%
727
May1st to 15thNight
65%
539
34%
1619
24%
539
73%
539
61%
712
May16th to endNight
64%
561
33%
1684
24%
561
71%
561
58%
754
June1st to 15thNight
72%
540
33%
1620
28%
540
75%
540
67%
684
June16th to endNight
82%
540
31%
1620
28%
540
84%
540
66%
690
July1st to 15thNight
76%
510
19%
1530
17%
510
77%
510
36%
880
July16th to endNight
73%
564
15%
1593
14%
531
73%
531
27%
1026
August1st to 15thNight
80%
539
22%
1611
20%
536
80%
536
37%
903
August16th to endNight
81%
573
27%
1830
27%
573
82%
573
39%
982
September1st to 15thNight
80%
681
28%
1941
25%
681
83%
681
45%
1057
September16th to endNight
78%
692
42%
1914
31%
692
85%
692
66%
878
October1st to 15thNight
72%
660
38%
1939
29%
660
78%
660
61%
880
October16th to endNight
79%
704
41%
2112
33%
704
85%
704
61%
945
November1st to 15thNight
76%
700
39%
2106
32%
700
82%
700
60%
946
November16th to endNight
72%
720
39%
2340
36%
720
78%
720
57%
1011
December1st to 15thNight
69%
720
34%
2340
33%
720
76%
720
50%
1089
December16th to endNight
62%
768
31%
2496
29%
768
68%
768
38%
1320

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
221332445%7%62%
47947
Night
3212323346%65%
47175
TransparencyDay
20%48%18%27%19%
47642
Night
18%48%19%28%20%
46981
SeeingDay
5%7%19%28%27%11%
5349
Night
4317%42%29%3
15516

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
26%25%5%24447%54%
1611
16th to endDay
4424322346%60%
1728
February1st to 15thDay
1324313347%62%
1590
16th to endDay
4424333247%59%
1625
March1st to 15thDay
2313313347%65%
1980
16th to endDay
1223223346%66%
2112
April1st to 15thDay
2213222347%67%
2039
16th to endDay
2212213325%72%
2214
May1st to 15thDay
1212212346%70%
2331
16th to endDay
221222334470%
2429
June1st to 15thDay
1111223479%
2340
16th to endDay
11121235%5%75%
2340
July1st to 15thDay
32136%47%6%8%8%45%
2340
16th to endDay
5%325%6%5%8%9%9%11%32%
2467
August1st to 15thDay
5%3246%47%6%8%10%41%
2340
16th to endDay
4214435%5%8%10%49%
2372
September1st to 15thDay
23144345%6%7%55%
2016
16th to endDay
111211235%77%
1904
October1st to 15thDay
211111323475%
1691
16th to endDay
22121222475%
1760
November1st to 15thDay
122213336%73%
1750
16th to endDay
322321223470%
1620
December1st to 15thDay
442432335%9%56%
1620
16th to endDay
4415%4245%46%56%
1728
January1st to 15thNight
4413313346%64%
2327
16th to endNight
4412314335%64%
2496
February1st to 15thNight
2313112346%68%
2259
16th to endNight
331322235%7%65%
1847
March1st to 15thNight
2311223346%68%
1980
16th to endNight
2112212346%70%
2112
April1st to 15thNight
213312447%66%
1909
16th to endNight
211212246%73%
1743
May1st to 15thNight
112222246%71%
1619
16th to endNight
322212235%73%
1684
June1st to 15thNight
221211235%76%
1620
16th to endNight
111212335%76%
1620
July1st to 15thNight
33135%36%6%7%9%49%
1620
16th to endNight
3326%6%38%7%7%12%36%
1701
August1st to 15thNight
22145%45%7%6%10%50%
1620
16th to endNight
2214436%6%8%10%49%
1830
September1st to 15thNight
331333447%7%56%
1941
16th to endNight
21221233475%
1914
October1st to 15thNight
2211212335%73%
1939
16th to endNight
121212222476%
2112
November1st to 15thNight
2112212245%71%
2106
16th to endNight
321221223473%
2340
December1st to 15thNight
3312222347%65%
2340
16th to endNight
5%5%14323447%57%
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
27%410%28%26%2
1612
16th to endDay
23%310%24%32%5%
1728
February1st to 15thDay
21%210%25%26%11%
1590
16th to endDay
25%26%23%31%9%
1625
March1st to 15thDay
18%3421%36%14%
1980
16th to endDay
17%26%20%37%14%
2112
April1st to 15thDay
17%2419%35%20%
2039
16th to endDay
15%2413%38%24%
2214
May1st to 15thDay
15%35%16%31%27%
2331
16th to endDay
16%36%11%31%30%
2432
June1st to 15thDay
9%237%25%52%
2340
16th to endDay
11%247%20%53%
2340
July1st to 15thDay
30%8%12%15%11%20%
2201
16th to endDay
37%13%17%17%10%3
2312
August1st to 15thDay
33%9%12%15%14%13%
2325
16th to endDay
28%8%14%16%20%11%
2372
September1st to 15thDay
25%7%12%17%19%18%
2016
16th to endDay
11%2416%33%31%
1904
October1st to 15thDay
13%36%17%33%25%
1691
16th to endDay
12%26%17%40%19%
1760
November1st to 15thDay
13%25%30%33%13%
1750
16th to endDay
19%2422%36%16%
1620
December1st to 15thDay
24%412%30%24%4
1620
16th to endDay
27%412%32%19%2
1728
January1st to 15thNight
21%47%28%32%4
2327
16th to endNight
22%28%25%34%6%
2496
February1st to 15thNight
18%29%25%28%15%
2270
16th to endNight
18%35%23%35%13%
1847
March1st to 15thNight
16%25%18%38%17%
1980
16th to endNight
15%36%19%38%17%
2112
April1st to 15thNight
17%35%18%33%22%
1909
16th to endNight
13%25%15%36%26%
1743
May1st to 15thNight
13%27%18%29%28%
1620
16th to endNight
14%25%13%31%32%
1685
June1st to 15thNight
11%226%20%56%
1620
16th to endNight
11%246%16%57%
1620
July1st to 15thNight
28%8%12%14%12%24%
1530
16th to endNight
34%12%20%15%12%5%
1593
August1st to 15thNight
26%8%16%16%16%15%
1611
16th to endNight
24%8%18%19%16%12%
1830
September1st to 15thNight
22%6%14%18%18%18%
1941
16th to endNight
12%25%15%29%35%
1914
October1st to 15thNight
13%36%19%25%30%
1939
16th to endNight
13%35%14%34%28%
2112
November1st to 15thNight
14%25%23%36%17%
2106
16th to endNight
15%25%20%32%23%
2340
December1st to 15thNight
18%310%26%31%9%
2340
16th to endNight
26%5%12%29%22%3
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
7%5%24%35%18%7%
90
16th to endDay
7%7%12%36%26%10%
96
February1st to 15thDay
3314%36%28%13%
105
16th to endDay
9%19%24%24%18%3
238
March1st to 15thDay
414%22%26%24%7%
270
16th to endDay
5%15%29%24%19%5%
288
April1st to 15thDay
7%16%28%19%16%11%
269
16th to endDay
6%19%32%23%14%3
270
May1st to 15thDay
5%13%29%29%17%4
288
16th to endDay
311%26%28%21%7%
330
June1st to 15thDay
36%25%29%25%10%
315
16th to endDay
1217%31%26%20%
315
July1st to 15thDay
313%37%30%13%
305
16th to endDay
6%7%27%34%23%
327
August1st to 15thDay
39%26%40%19%
315
16th to endDay
5%19%23%37%21%
332
September1st to 15thDay
5%112%29%40%10%
315
16th to endDay
4419%27%32%12%
288
October1st to 15thDay
3316%32%29%15%
131
16th to endDay
7%13%36%35%7%
96
November1st to 15thDay
5%5%7%27%38%14%
90
16th to endDay
7%5%26%28%28%2
90
December1st to 15thDay
6%5%12%37%30%7%
90
16th to endDay
9%11%16%36%22%3
96
January1st to 15thNight
6%315%43%26%4
720
16th to endNight
7%416%43%25%2
768
February1st to 15thNight
3220%47%21%3
704
16th to endNight
46%26%47%14%
632
March1st to 15thNight
35%24%42%22%1
720
16th to endNight
25%24%45%19%1
768
April1st to 15thNight
27%33%39%16%
650
16th to endNight
37%32%40%14%2
540
May1st to 15thNight
2326%49%17%
540
16th to endNight
4423%44%22%1
563
June1st to 15thNight
3220%52%20%
540
16th to endNight
212%55%29%
540
July1st to 15thNight
47%44%41%1
510
16th to endNight
47%31%48%6%
564
August1st to 15thNight
5%228%55%7%
539
16th to endNight
26%35%49%5%
573
September1st to 15thNight
46%36%48%4
681
16th to endNight
2113%38%39%5%
692
October1st to 15thNight
2219%45%26%3
660
16th to endNight
1113%41%37%4
704
November1st to 15thNight
2116%43%31%4
700
16th to endNight
3217%41%28%5%
720
December1st to 15thNight
6%317%44%26%2
720
16th to endNight
7%420%43%22%2
768
Page generated at 2017-09-25 06:02:21. Version ac04

Copyright 2017 A. Danko


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