Bullhead City
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bullhead City clear sky chart from 2005-11-05 to 2017-09-17.

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
68%
15876
39%
46946
28%
15836
78%
15836
62%
20578

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
42%
720
35%
2327
18%
716
65%
716
49%
1038
January16th to endNight
48%
768
38%
2471
24%
768
68%
768
47%
1152
February1st to 15thNight
54%
696
39%
2112
25%
696
74%
696
57%
956
February16th to endNight
54%
632
38%
1895
30%
632
69%
632
51%
910
March1st to 15thNight
62%
720
38%
2079
29%
720
75%
720
60%
940
March16th to endNight
68%
768
41%
2112
29%
768
77%
768
64%
951
April1st to 15thNight
61%
719
36%
1862
20%
719
70%
719
63%
896
April16th to endNight
67%
618
45%
1698
26%
618
78%
618
76%
705
May1st to 15thNight
71%
539
40%
1619
28%
539
79%
539
71%
647
May16th to endNight
73%
561
39%
1685
29%
561
78%
561
73%
666
June1st to 15thNight
81%
540
35%
1620
31%
540
83%
540
78%
618
June16th to endNight
87%
540
36%
1620
32%
540
88%
540
79%
628
July1st to 15thNight
88%
510
30%
1530
26%
510
88%
510
63%
665
July16th to endNight
82%
564
33%
1593
29%
531
83%
531
51%
786
August1st to 15thNight
86%
561
39%
1633
30%
558
87%
558
66%
715
August16th to endNight
88%
764
43%
1910
31%
764
88%
764
68%
942
September1st to 15thNight
86%
720
37%
1946
29%
720
88%
720
68%
901
September16th to endNight
81%
664
47%
1837
37%
664
89%
664
80%
749
October1st to 15thNight
73%
660
45%
1815
35%
660
81%
660
69%
805
October16th to endNight
73%
704
45%
2131
37%
704
84%
704
69%
865
November1st to 15thNight
65%
700
40%
2275
31%
700
80%
700
66%
901
November16th to endNight
62%
720
44%
2340
34%
720
78%
720
65%
929
December1st to 15thNight
51%
720
39%
2340
24%
720
72%
720
52%
1043
December16th to endNight
44%
768
38%
2496
22%
768
65%
768
45%
1170

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
212212235%73%
47832
Night
2112212335%73%
47141
TransparencyDay
13%1313%26%42%
47527
Night
13%1313%26%41%
46947
SeeingDay
38%25%36%20%5%
5636
Night
3320%41%27%2
15887

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
3312212236%70%
1611
16th to endDay
6%213312237%65%
1752
February1st to 15thDay
3211112347%69%
1751
16th to endDay
5%213323338%63%
1579
March1st to 15thDay
21212236%74%
1880
16th to endDay
1112112346%72%
2112
April1st to 15thDay
2212212235%71%
2083
16th to endDay
11111123480%
2261
May1st to 15thDay
1111135%81%
2331
16th to endDay
1121212479%
2429
June1st to 15thDay
11112385%
2340
16th to endDay
1112287%
2340
July1st to 15thDay
2212223246%68%
2340
16th to endDay
32134235%5%8%58%
2467
August1st to 15thDay
2112213346%71%
2315
16th to endDay
211213335%72%
2292
September1st to 15thDay
112223247%71%
2013
16th to endDay
111122384%
1828
October1st to 15thDay
111221233475%
1815
16th to endDay
211223480%
1741
November1st to 15thDay
21112233377%
1584
16th to endDay
211111335%76%
1620
December1st to 15thDay
3213213347%64%
1620
16th to endDay
6%312212346%63%
1728
January1st to 15thNight
3212223345%68%
2327
16th to endNight
4213213346%65%
2471
February1st to 15thNight
3213212236%70%
2101
16th to endNight
5%312212337%65%
1895
March1st to 15thNight
21221345%6%69%
2079
16th to endNight
2111212346%72%
2112
April1st to 15thNight
2111213336%73%
1862
16th to endNight
1111111135%80%
1698
May1st to 15thNight
112245%79%
1619
16th to endNight
1112235%79%
1684
June1st to 15thNight
1122483%
1620
16th to endNight
11211385%
1620
July1st to 15thNight
212213446%70%
1620
16th to endNight
32133245%7%8%57%
1701
August1st to 15thNight
1212212347%71%
1642
16th to endNight
211212336%73%
1910
September1st to 15thNight
11121334474%
1946
16th to endNight
1122386%
1837
October1st to 15thNight
21112235%77%
1815
16th to endNight
1111122481%
2131
November1st to 15thNight
111112235%77%
2275
16th to endNight
21121235%77%
2340
December1st to 15thNight
5%112213346%66%
2340
16th to endNight
7%412212336%64%
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
15%25%20%38%16%
1612
16th to endDay
20%15%21%33%17%
1752
February1st to 15thDay
15%16%17%32%26%
1751
16th to endDay
21%1319%30%24%
1579
March1st to 15thDay
12%1313%31%36%
1880
16th to endDay
12%2416%34%30%
2112
April1st to 15thDay
15%1112%29%39%
2083
16th to endDay
8%111%30%47%
2261
May1st to 15thDay
8%110%27%50%
2331
16th to endDay
10%117%24%55%
2432
June1st to 15thDay
6%5%15%71%
2340
16th to endDay
5%39%80%
2340
July1st to 15thDay
16%238%16%53%
2201
16th to endDay
20%37%16%21%30%
2312
August1st to 15thDay
13%2312%21%46%
2300
16th to endDay
14%239%24%45%
2292
September1st to 15thDay
13%2310%23%45%
2013
16th to endDay
7%16%19%64%
1828
October1st to 15thDay
13%129%25%47%
1815
16th to endDay
9%1311%27%46%
1741
November1st to 15thDay
11%1214%33%35%
1584
16th to endDay
10%1417%33%31%
1620
December1st to 15thDay
18%18%26%28%17%
1620
16th to endDay
21%29%26%26%13%
1728
January1st to 15thNight
17%25%17%35%21%
2327
16th to endNight
21%1419%27%25%
2471
February1st to 15thNight
16%15%18%26%31%
2112
16th to endNight
20%1415%32%25%
1895
March1st to 15thNight
14%1313%32%34%
2079
16th to endNight
12%1216%32%34%
2112
April1st to 15thNight
13%1312%30%38%
1862
16th to endNight
7%110%28%51%
1698
May1st to 15thNight
8%128%29%49%
1620
16th to endNight
8%118%24%55%
1685
June1st to 15thNight
6%6%14%71%
1620
16th to endNight
6%210%79%
1620
July1st to 15thNight
13%248%17%53%
1530
16th to endNight
20%35%16%22%31%
1593
August1st to 15thNight
12%2210%23%48%
1633
16th to endNight
12%228%24%48%
1910
September1st to 15thNight
11%3414%21%45%
1946
16th to endNight
6%15%18%67%
1837
October1st to 15thNight
11%127%28%48%
1815
16th to endNight
9%139%21%54%
2131
November1st to 15thNight
11%1212%33%40%
2275
16th to endNight
11%314%29%40%
2340
December1st to 15thNight
17%25%19%31%23%
2340
16th to endNight
21%17%23%29%16%
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
14%13%34%32%5%
90
16th to endDay
5%6%35%40%9%2
120
February1st to 15thDay
6%13%38%28%11%1
266
16th to endDay
10%15%34%28%9%
238
March1st to 15thDay
5%12%29%35%15%1
270
16th to endDay
5%14%32%31%13%2
288
April1st to 15thDay
5%18%31%24%12%6%
269
16th to endDay
420%34%27%10%2
270
May1st to 15thDay
212%34%34%11%3
288
16th to endDay
10%33%34%16%4
330
June1st to 15thDay
26%27%40%18%3
315
16th to endDay
219%42%23%10%
315
July1st to 15thDay
2112%45%28%9%
305
16th to endDay
119%43%35%7%
327
August1st to 15thDay
2215%44%27%6%
315
16th to endDay
310%40%31%12%
332
September1st to 15thDay
1217%40%29%7%
315
16th to endDay
29%19%34%27%6%
260
October1st to 15thDay
110%30%36%20%1
255
16th to endDay
2217%43%26%6%
102
November1st to 15thDay
26%23%25%33%8%
90
16th to endDay
37%52%26%10%
90
December1st to 15thDay
46%21%58%8%
90
16th to endDay
14%9%30%36%8%1
96
January1st to 15thNight
5%8%40%37%8%
720
16th to endNight
6%7%32%44%8%
768
February1st to 15thNight
4331%45%13%1
704
16th to endNight
7%5%28%42%14%1
632
March1st to 15thNight
45%23%44%19%2
720
16th to endNight
3419%46%23%2
768
April1st to 15thNight
46%25%41%20%2
719
16th to endNight
1423%47%19%2
618
May1st to 15thNight
2419%42%28%1
540
16th to endNight
1320%43%28%2
563
June1st to 15thNight
114%47%32%1
540
16th to endNight
9%44%42%2
540
July1st to 15thNight
2340%49%3
510
16th to endNight
3235%53%3
564
August1st to 15thNight
3335%53%3
561
16th to endNight
3225%57%10%
764
September1st to 15thNight
16%32%50%8%
720
16th to endNight
1113%36%40%6%
664
October1st to 15thNight
3217%50%23%2
660
16th to endNight
2317%46%27%3
704
November1st to 15thNight
2326%44%21%2
700
16th to endNight
3426%45%18%2
720
December1st to 15thNight
6%5%33%46%8%
720
16th to endNight
9%7%34%40%7%
768
Page generated at 2017-09-18 05:38:21. Version ac04

Copyright 2017 A. Danko


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