Pioneertown Mountains Preserve
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Pioneertown Mountains Preserve clear sky chart from 2005-11-05 to 2019-06-10.

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
72%
18501
40%
53943
30%
18463
80%
18463
64%
23515

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
60%
837
34%
2717
28%
836
71%
836
46%
1269
January16th to endNight
57%
896
38%
2744
27%
896
71%
896
48%
1297
February1st to 15thNight
60%
819
40%
2468
29%
818
76%
818
54%
1129
February16th to endNight
55%
736
38%
2207
31%
736
68%
736
53%
1029
March1st to 15thNight
59%
840
36%
2505
29%
840
73%
840
54%
1141
March16th to endNight
66%
896
38%
2405
26%
896
77%
896
61%
1129
April1st to 15thNight
56%
839
40%
2099
18%
839
69%
839
59%
1053
April16th to endNight
62%
832
41%
2080
18%
832
73%
832
73%
940
May1st to 15thNight
72%
629
44%
1889
30%
629
78%
629
75%
718
May16th to endNight
72%
657
39%
1973
28%
657
77%
657
78%
751
June1st to 15thNight
80%
612
38%
1836
31%
612
83%
612
80%
694
June16th to endNight
84%
585
37%
1755
32%
585
87%
585
83%
660
July1st to 15thNight
88%
555
33%
1665
30%
555
88%
555
70%
682
July16th to endNight
87%
612
35%
1737
30%
579
88%
579
62%
777
August1st to 15thNight
93%
764
40%
1910
26%
761
93%
761
80%
864
August16th to endNight
92%
828
43%
2070
30%
828
92%
828
77%
949
September1st to 15thNight
92%
780
43%
2040
35%
780
93%
780
78%
897
September16th to endNight
87%
776
48%
2145
42%
776
92%
776
86%
846
October1st to 15thNight
75%
780
46%
2145
36%
780
84%
780
72%
925
October16th to endNight
78%
832
45%
2516
41%
832
86%
832
70%
1012
November1st to 15thNight
74%
820
41%
2665
37%
820
85%
820
66%
1044
November16th to endNight
72%
840
41%
2730
39%
840
82%
840
58%
1141
December1st to 15thNight
63%
840
37%
2730
30%
840
74%
840
49%
1234
December16th to endNight
55%
896
37%
2912
27%
896
69%
896
45%
1334

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
111212235%75%
54563
Night
111112235%76%
54142
TransparencyDay
12%2416%28%35%
54259
Night
11%25%16%29%34%
53948
SeeingDay
314%27%32%16%4
8153
Night
25%16%32%32%10%
18512

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
3312223346%66%
1881
16th to endDay
3212324346%66%
2181
February1st to 15thDay
1212214346%69%
2051
16th to endDay
112322348%67%
1839
March1st to 15thDay
112212347%71%
2114
16th to endDay
112112346%73%
2520
April1st to 15thDay
1212112246%72%
2509
16th to endDay
111211226%80%
2485
May1st to 15thDay
11112135%79%
2721
16th to endDay
11111123480%
2845
June1st to 15thDay
111112484%
2653
16th to endDay
11111188%
2535
July1st to 15thDay
2212212345%70%
2535
16th to endDay
211222445%7%65%
2673
August1st to 15thDay
112212335%75%
2293
16th to endDay
2123246%76%
2484
September1st to 15thDay
2121233476%
2249
16th to endDay
1111111286%
2145
October1st to 15thDay
11111122480%
2145
16th to endDay
1111113481%
2055
November1st to 15thDay
11122235%77%
1854
16th to endDay
211212347%70%
1890
December1st to 15thDay
2213213338%65%
1890
16th to endDay
232322348%65%
2016
January1st to 15thNight
1312323347%65%
2717
16th to endNight
3213323346%66%
2744
February1st to 15thNight
1212322345%71%
2461
16th to endNight
221221335%9%66%
2207
March1st to 15thNight
1211213348%69%
2505
16th to endNight
11113347%73%
2405
April1st to 15thNight
212212325%75%
2099
16th to endNight
11122483%
2080
May1st to 15thNight
11225%83%
1889
16th to endNight
1112485%
1972
June1st to 15thNight
1112387%
1836
16th to endNight
111290%
1755
July1st to 15thNight
1111224477%
1755
16th to endNight
212212336%72%
1845
August1st to 15thNight
111123482%
1919
16th to endNight
11111113482%
2070
September1st to 15thNight
111123483%
2040
16th to endNight
1192%
2145
October1st to 15thNight
111122382%
2145
16th to endNight
1111112482%
2516
November1st to 15thNight
1112235%79%
2665
16th to endNight
212211345%74%
2730
December1st to 15thNight
2212323347%67%
2730
16th to endNight
321222235%6%67%
2912

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
18%36%21%28%21%
1882
16th to endDay
18%37%21%28%20%
2181
February1st to 15thDay
16%35%19%30%24%
2051
16th to endDay
16%38%22%32%16%
1839
March1st to 15thDay
13%26%24%30%22%
2114
16th to endDay
12%38%24%31%19%
2520
April1st to 15thDay
13%25%20%34%22%
2509
16th to endDay
8%1419%36%30%
2485
May1st to 15thDay
9%1317%35%32%
2721
16th to endDay
8%2416%36%31%
2848
June1st to 15thDay
5%129%23%57%
2653
16th to endDay
7%1411%74%
2535
July1st to 15thDay
15%339%19%48%
2396
16th to endDay
16%47%17%23%29%
2518
August1st to 15thDay
10%2310%21%50%
2279
16th to endDay
11%2312%27%42%
2484
September1st to 15thDay
11%339%24%48%
2249
16th to endDay
7%117%29%52%
2145
October1st to 15thDay
10%2211%33%40%
2145
16th to endDay
8%2311%30%44%
2055
November1st to 15thDay
11%2418%33%29%
1854
16th to endDay
13%25%19%29%28%
1890
December1st to 15thDay
18%39%22%24%21%
1890
16th to endDay
18%410%23%26%17%
2016
January1st to 15thNight
19%47%19%26%22%
2717
16th to endNight
18%36%21%25%23%
2744
February1st to 15thNight
15%35%20%28%26%
2472
16th to endNight
15%47%21%28%21%
2207
March1st to 15thNight
13%46%22%29%22%
2505
16th to endNight
11%37%21%37%18%
2405
April1st to 15thNight
13%35%22%31%23%
2099
16th to endNight
7%1316%42%28%
2080
May1st to 15thNight
5%1320%37%32%
1890
16th to endNight
5%1418%39%31%
1973
June1st to 15thNight
5%1211%21%57%
1836
16th to endNight
416%14%73%
1755
July1st to 15thNight
10%1310%18%55%
1665
16th to endNight
13%36%20%25%31%
1737
August1st to 15thNight
6%2212%24%50%
1910
16th to endNight
8%1210%31%44%
2070
September1st to 15thNight
6%249%24%52%
2040
16th to endNight
46%32%55%
2145
October1st to 15thNight
8%2312%35%38%
2145
16th to endNight
8%138%30%46%
2516
November1st to 15thNight
9%2414%37%31%
2665
16th to endNight
12%35%20%30%28%
2730
December1st to 15thNight
17%38%19%26%24%
2730
16th to endNight
17%410%19%28%19%
2912

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
13%12%20%32%18%3
180
16th to endDay
423%29%26%12%2
357
February1st to 15thDay
5%20%32%24%11%4
386
16th to endDay
6%31%26%24%10%
342
March1st to 15thDay
5%28%28%24%11%1
390
16th to endDay
5%19%38%26%9%1
416
April1st to 15thDay
7%22%31%21%13%2
389
16th to endDay
327%33%23%8%3
378
May1st to 15thDay
414%31%31%11%5%
408
16th to endDay
318%33%30%10%4
458
June1st to 15thDay
29%31%34%15%6%
412
16th to endDay
25%27%36%17%10%
375
July1st to 15thDay
216%48%21%10%
365
16th to endDay
4116%46%21%10%
391
August1st to 15thDay
2222%41%22%8%
359
16th to endDay
1119%41%26%9%
396
September1st to 15thDay
2325%47%19%1
375
16th to endDay
28%27%34%22%3
375
October1st to 15thDay
114%36%34%13%
375
16th to endDay
19%26%29%26%5%
294
November1st to 15thDay
112%21%35%25%3
180
16th to endDay
315%25%27%23%5%
180
December1st to 15thDay
6%15%17%35%22%1
180
16th to endDay
219%20%28%25%4
192
January1st to 15thNight
47%21%34%21%10%
840
16th to endNight
48%24%31%25%6%
896
February1st to 15thNight
38%23%34%23%7%
824
16th to endNight
37%31%32%19%5%
736
March1st to 15thNight
29%25%33%22%6%
840
16th to endNight
19%19%37%24%7%
896
April1st to 15thNight
210%26%30%23%6%
839
16th to endNight
19%24%31%23%9%
832
May1st to 15thNight
6%19%38%28%6%
630
16th to endNight
420%37%29%6%
659
June1st to 15thNight
215%42%33%5%
612
16th to endNight
112%37%42%6%
585
July1st to 15thNight
3329%51%12%
555
16th to endNight
3229%52%11%
612
August1st to 15thNight
225%50%19%
764
16th to endNight
2118%51%24%
828
September1st to 15thNight
1228%49%17%
780
16th to endNight
19%29%44%15%
776
October1st to 15thNight
1217%36%33%8%
780
16th to endNight
1412%30%35%16%
832
November1st to 15thNight
417%34%33%9%
820
16th to endNight
35%15%31%30%13%
840
December1st to 15thNight
37%20%36%24%7%
840
16th to endNight
5%12%23%29%22%6%
896
Page generated at 2019-06-10 16:29:50. Version ac04

Copyright 2019 A. Danko


Pioneertown Mountains Preserve Clear Sky Chart |Charts Home