Sedona
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Sedona clear sky chart from 2005-11-05 to 2017-08-12.

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
63%
15469
34%
46540
25%
15430
73%
15430
49%
22720

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
52%
719
32%
2327
23%
716
66%
716
40%
1152
January16th to endNight
52%
768
36%
2496
27%
768
67%
768
38%
1286
February1st to 15thNight
59%
700
33%
2214
25%
700
72%
700
45%
1065
February16th to endNight
50%
632
35%
1890
27%
632
62%
632
41%
1003
March1st to 15thNight
53%
720
37%
1980
25%
720
66%
720
50%
1018
March16th to endNight
61%
768
36%
2112
23%
768
72%
768
53%
1050
April1st to 15thNight
51%
692
29%
1951
14%
692
62%
692
48%
991
April16th to endNight
56%
540
43%
1677
27%
540
72%
540
58%
692
May1st to 15thNight
61%
539
37%
1619
25%
539
70%
539
57%
702
May16th to endNight
60%
561
36%
1684
25%
561
67%
561
58%
733
June1st to 15thNight
67%
540
33%
1620
27%
540
70%
540
66%
677
June16th to endNight
77%
540
34%
1620
31%
540
79%
540
69%
663
July1st to 15thNight
81%
510
22%
1530
19%
510
81%
510
44%
807
July16th to endNight
81%
564
20%
1593
17%
531
81%
531
36%
922
August1st to 15thNight
82%
527
28%
1575
24%
524
83%
524
43%
823
August16th to endNight
84%
561
30%
1674
28%
561
85%
561
45%
872
September1st to 15thNight
80%
660
30%
1815
24%
660
83%
660
47%
1000
September16th to endNight
75%
656
42%
1815
29%
656
83%
656
65%
817
October1st to 15thNight
66%
660
38%
1900
26%
660
76%
660
56%
905
October16th to endNight
67%
704
42%
2112
31%
704
77%
704
58%
962
November1st to 15thNight
63%
700
37%
2160
27%
700
75%
700
54%
1002
November16th to endNight
58%
720
39%
2340
30%
720
72%
720
51%
1053
December1st to 15thNight
60%
720
35%
2340
29%
720
71%
720
43%
1151
December16th to endNight
51%
768
31%
2496
25%
768
62%
768
34%
1374

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
5%313323446%62%
47432
Night
5%312213346%65%
46736
TransparencyDay
21%46%17%28%21%
47127
Night
19%46%17%28%23%
46542
SeeingDay
9%16%29%30%11%3
5273
Night
6%6%18%32%29%6%
15477

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
7%32212345%65%
1611
16th to endDay
10%6%12212236%60%
1728
February1st to 15thDay
5%7%13212337%61%
1647
16th to endDay
10%7%13322336%55%
1582
March1st to 15thDay
5%5%12213346%62%
1980
16th to endDay
5%412213346%64%
2112
April1st to 15thDay
4312323347%63%
1996
16th to endDay
4212212236%69%
2280
May1st to 15thDay
4212212336%67%
2331
16th to endDay
3213213335%68%
2429
June1st to 15thDay
111112235%78%
2340
16th to endDay
11121223477%
2340
July1st to 15thDay
32135%37%7%8%7%47%
2340
16th to endDay
8%425%6%47%8%9%9%34%
2467
August1st to 15thDay
5%425%6%36%6%6%7%46%
2290
16th to endDay
5%3246%35%6%7%9%46%
2174
September1st to 15thDay
5%2244345%5%7%53%
1815
16th to endDay
312212235%72%
1815
October1st to 15thDay
42221333470%
1730
16th to endDay
312212245%72%
1760
November1st to 15thDay
421223336%70%
1697
16th to endDay
7%321123471%
1620
December1st to 15thDay
8%5%13222337%59%
1620
16th to endDay
12%6%2321324454%
1728
January1st to 15thNight
7%413322245%62%
2327
16th to endNight
10%5%12213235%62%
2496
February1st to 15thNight
5%5%12212246%65%
2203
16th to endNight
8%6%12213246%60%
1890
March1st to 15thNight
5%412112246%66%
1980
16th to endNight
5%311113335%69%
2112
April1st to 15thNight
6%212213347%64%
1951
16th to endNight
211112236%76%
1677
May1st to 15thNight
311212336%74%
1619
16th to endNight
211212235%75%
1684
June1st to 15thNight
21112235%78%
1620
16th to endNight
11111113481%
1620
July1st to 15thNight
23125%25%5%7%7%56%
1620
16th to endNight
32135%35%8%10%12%43%
1701
August1st to 15thNight
22135%25%5%6%9%54%
1584
16th to endNight
22134247%6%10%54%
1674
September1st to 15thNight
32143245%6%6%58%
1815
16th to endNight
31111123477%
1815
October1st to 15thNight
322113335%71%
1900
16th to endNight
221221223473%
2112
November1st to 15thNight
4211212335%70%
2160
16th to endNight
6%31112235%70%
2340
December1st to 15thNight
8%42122347%61%
2340
16th to endNight
11%5%1322324455%
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
21%35%20%32%16%
1612
16th to endDay
26%26%18%32%13%
1728
February1st to 15thDay
23%47%23%21%19%
1647
16th to endDay
29%35%20%27%13%
1582
March1st to 15thDay
22%4218%36%15%
1980
16th to endDay
21%4422%32%15%
2112
April1st to 15thDay
20%3420%33%17%
1996
16th to endDay
15%4316%38%21%
2280
May1st to 15thDay
16%3317%33%23%
2331
16th to endDay
17%3312%37%25%
2432
June1st to 15thDay
9%228%30%46%
2340
16th to endDay
11%235%23%53%
2340
July1st to 15thDay
26%9%11%14%15%22%
2201
16th to endDay
35%12%17%15%15%3
2312
August1st to 15thDay
31%7%9%17%18%15%
2275
16th to endDay
29%8%11%19%22%9%
2174
September1st to 15thDay
27%7%9%16%20%19%
1815
16th to endDay
13%3414%36%28%
1815
October1st to 15thDay
17%3416%30%28%
1730
16th to endDay
14%2415%35%27%
1760
November1st to 15thDay
15%3421%31%22%
1697
16th to endDay
17%2319%30%25%
1620
December1st to 15thDay
26%38%25%25%10%
1620
16th to endDay
32%46%22%25%7%
1728
January1st to 15thNight
23%3420%31%15%
2327
16th to endNight
26%3319%29%17%
2496
February1st to 15thNight
21%27%20%26%21%
2214
16th to endNight
25%3420%30%15%
1890
March1st to 15thNight
19%3316%39%17%
1980
16th to endNight
16%36%22%33%16%
2112
April1st to 15thNight
20%3417%35%19%
1951
16th to endNight
10%2316%39%27%
1677
May1st to 15thNight
11%35%19%30%28%
1620
16th to endNight
13%2214%37%30%
1685
June1st to 15thNight
10%217%26%51%
1620
16th to endNight
9%115%17%63%
1620
July1st to 15thNight
22%6%13%14%18%24%
1530
16th to endNight
26%10%20%19%16%5%
1593
August1st to 15thNight
21%8%12%19%20%18%
1575
16th to endNight
21%7%13%21%24%12%
1674
September1st to 15thNight
22%6%12%17%21%20%
1815
16th to endNight
11%2312%36%33%
1815
October1st to 15thNight
15%35%18%27%29%
1900
16th to endNight
14%3413%29%35%
2112
November1st to 15thNight
16%3420%32%22%
2160
16th to endNight
17%3316%29%29%
2340
December1st to 15thNight
22%47%23%26%15%
2340
16th to endNight
30%38%21%26%8%
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
33%12%16%28%8%
90
16th to endDay
14%20%23%22%16%1
96
February1st to 15thDay
8%17%34%24%12%1
162
16th to endDay
18%28%28%18%6%
238
March1st to 15thDay
10%21%34%20%11%1
270
16th to endDay
11%25%35%20%5%2
288
April1st to 15thDay
11%30%33%13%8%2
269
16th to endDay
10%33%36%12%5%1
270
May1st to 15thDay
10%24%38%18%6%1
288
16th to endDay
6%26%32%27%5%1
330
June1st to 15thDay
323%40%21%8%3
315
16th to endDay
35%35%40%11%3
315
July1st to 15thDay
45%30%45%9%4
305
16th to endDay
9%214%44%21%7%
327
August1st to 15thDay
6%217%47%20%5%
300
16th to endDay
5%419%44%20%4
268
September1st to 15thDay
8%7%29%40%9%5%
255
16th to endDay
7%12%26%36%11%4
255
October1st to 15thDay
5%20%32%27%10%2
170
16th to endDay
11%10%26%29%18%4
96
November1st to 15thDay
10%8%25%27%23%4
90
16th to endDay
15%16%28%27%11%
90
December1st to 15thDay
10%7%25%36%17%2
90
16th to endDay
25%10%22%32%8%1
96
January1st to 15thNight
9%9%22%33%17%6%
720
16th to endNight
13%10%19%34%18%3
768
February1st to 15thNight
9%8%18%40%20%2
704
16th to endNight
11%9%26%32%17%2
632
March1st to 15thNight
8%9%25%33%19%4
720
16th to endNight
5%9%21%36%23%3
768
April1st to 15thNight
7%10%26%34%17%3
692
16th to endNight
213%25%37%17%3
540
May1st to 15thNight
310%21%39%22%2
540
16th to endNight
39%24%31%28%3
563
June1st to 15thNight
2422%37%29%2
540
16th to endNight
2213%35%40%5%
540
July1st to 15thNight
4426%52%11%
510
16th to endNight
31115%59%18%
564
August1st to 15thNight
31217%59%15%
527
16th to endNight
2221%54%18%
561
September1st to 15thNight
46%26%49%12%
660
16th to endNight
45%12%26%39%12%
656
October1st to 15thNight
5%6%20%35%27%4
660
16th to endNight
3419%33%27%10%
704
November1st to 15thNight
5%5%21%40%20%6%
700
16th to endNight
7%7%23%33%20%7%
720
December1st to 15thNight
11%5%19%38%23%2
720
16th to endNight
14%7%21%36%16%3
768
Page generated at 2017-08-13 11:16:14. Version ac04

Copyright 2017 A. Danko


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